Stomatal regulation is critical for mangroves to survive in the hyper-saline intertidal zone where water stress is severe and water availability is highly fluctuant.However,very little is known about the stomatal sens...Stomatal regulation is critical for mangroves to survive in the hyper-saline intertidal zone where water stress is severe and water availability is highly fluctuant.However,very little is known about the stomatal sensitivity to vapour pressure deficit(VPD)in mangroves,and its co-ordination with stomatal morphology and leaf hydraulic traits.We measured the stomatal response to a step increase in VPD in situ,stomatal anatomy,leaf hydraulic vulnerability and pressure-volume traits in nine true mangrove species of five families and collected the data of genome size.We aimed to answer two questions:(1)Does stomatal morphology influence stomatal dynamics in response to a high VPD in mangroves?with a consideration of possible influence of genome size on stomatal morphology;and(2)do leaf hydraulic traits influence stomatal sensitivity to VPD in mangroves?We found that the stomata of mangrove plants were highly sensitive to a step rise in VPD and the stomatal responses were directly affected by stomatal anatomy and hydraulic traits.Smaller,denser stomata was correlated with faster stomatal closure at high VPD across the species of Rhizophoraceae,and stomata size negatively and vein density positively correlated with genome size.Less negative leaf osmotic pressure at the full turgor(πo)was related to higher operating steady-state stomatal conductance(gs);and a higher leaf capacitance(Cleaf)and more embolism resistant leaf xylem were associated with slower stomatal responses to an increase in VPD.In addition,stomatal responsiveness to VPD was indirectly affected by leaf morphological traits,which were affected by site salinity and consequently leaf water status.Our results demonstrate that mangroves display a unique relationship between genome size,stomatal size and vein packing,and that stomatal responsiveness to VPD is regulated by leaf hydraulic traits and stomatal morphology.Our work provides a quantitative framework to better understand of stomatal regulation in mangroves in an environment with high salinity and dynamic water availability.展开更多
The guava plant has achieved viable significance in subtropics and tropics owing to its flexibility to climatic environments,soil conditions and higher human consumption.It is cultivated in vast areas of Asian and Non...The guava plant has achieved viable significance in subtropics and tropics owing to its flexibility to climatic environments,soil conditions and higher human consumption.It is cultivated in vast areas of Asian and Non-Asian countries,including Pakistan.The guava plant is vulnerable to diseases,specifically the leaves and fruit,which result in massive crop and profitability losses.The existing plant leaf disease detection techniques can detect only one disease from a leaf.However,a single leaf may contain symptoms of multiple diseases.This study has proposed a hybrid deep learning-based framework for the real-time detection of multiple diseases from a single guava leaf in several steps.Firstly,Guava Infected Patches Modified MobileNetV2 and U-Net(GIP-MU-NET)has been proposed to segment the infected guava patches.The proposed model consists of modified MobileNetv2 as an encoder,and the U-Net model’s up-sampling layers are used as a decoder part.Secondly,the Guava Leaf SegmentationModel(GLSM)is proposed to segment the healthy and infected leaves.In the final step,the Guava Multiple Leaf Diseases Detection(GMLDD)model based on the YOLOv5 model detects various diseases from a guava leaf.Two self-collected datasets(the Guava Patches Dataset and the Guava Leaf Diseases Dataset)are used for training and validation.The proposed method detected the various defects,including five distinct classes,i.e.,anthracnose,insect attack,nutrition deficiency,wilt,and healthy.On average,the GIP-MU-Net model achieved 92.41%accuracy,the GLSM gained 83.40%accuracy,whereas the proposed GMLDD technique achieved 73.3%precision,73.1%recall,71.0%mAP@0.5 and 50.3 mAP@0.5:0.95 scores for all the aforesaid classes.展开更多
The morphological development of rice(Oryza sativa L.)leaves is closely related to plant architecture,physiological activities,and resistance.However,it is unclear whether there is a co-regulatory relationship between...The morphological development of rice(Oryza sativa L.)leaves is closely related to plant architecture,physiological activities,and resistance.However,it is unclear whether there is a co-regulatory relationship between the morphological development of leaves and adaptation to drought environment.In this study,a drought-sensitive,roll-enhanced,and narrow-leaf mutant(renl1)was induced from a semi-rolled leaf mutant(srl1)by ethyl methane sulfonate(EMS),which was obtained from Nipponbare(NPB)through EMS.Map-based cloning and functional validation showed that RENL1 encodes a cellulose synthase,allelic to NRL1/OsCLSD4.The RENL1 mutation resulted in reduced vascular bundles,vesicular cells,cellulose,and hemicellulose contents in cell walls,diminishing the water-holding capacity of leaves.In addition,the root system of the renl1 mutant was poorly developed and its ability to scavenge reactive oxygen species(ROS)was decreased,leading to an increase in ROS after drought stress.Meanwhile,genetic results showed that RENL1 and SRL1 synergistically regulated cell wall components.Our results revealed a theoretical basis for further elucidating the molecular regulation mechanism of cellulose on rice drought tolerance,and provided a new genetic resource for enhancing the synergistic regulation network of plant type and stress resistance,thereby realizing simultaneous improvement of multiple traits in rice.展开更多
Sweet potato leaf tips have high nutritional value,and exploring the differences in the metabolic profiles of leaf tips among different sweet potato varieties can provide information to improve their qualities.In this...Sweet potato leaf tips have high nutritional value,and exploring the differences in the metabolic profiles of leaf tips among different sweet potato varieties can provide information to improve their qualities.In this study,a UPLC-Q-Exactive Orbitrap/MS-based untargeted metabolomics method was used to evaluate the metabolites in leaf tips of 32 sweet potato varieties.Three varieties with distinct overall metabolic profiles(A01,A02,and A03),two varieties with distinct profiles of phenolic acids(A20 and A18),and three varieties with distinct profiles of flavonoids(A05,A12,and A16)were identified.In addition,a total of 163 and 29 differentially expressed metabolites correlated with the color and leaf shape of sweet potato leaf tips,respectively,were identified through morphological characterization.Group comparison analysis of the phenotypic traits and a metabolite-phenotypic trait correlation analysis indicated that the color differences of sweet potato leaf tips were markedly associated with flavonoids.Also,the level of polyphenols was correlated with the leaf shape of sweet potato leaf tips,with lobed leaf types having higher levels of polyphenols than the entire leaf types.The findings on the metabolic profiles and differentially expressed metabolites associated with the morphology of sweet potato leaf tips can provide useful information for breeding sweet potato varieties with higher nutritional value.展开更多
Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and s...Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.展开更多
Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the act...Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the activities of Chl a-degrading enzymes after silking,and the post-silking dry matter accumulation and grain yield under multiple planting densities and N fertilization rates.The dynamic change of GLA_(ear)after silking fitted to the logistic model,and the GLA_(ear) duration and the GLAearat 42 d after silking were affected mainly by the duration of the initial senescence period(T_(1))which was a key factor of the leaf senescence.The average chlorophyllase(CLH)activity was 8.3 times higher than pheophytinase activity and contributed most to the Chl content,indicating that CLH is a key enzyme for degrading Chl a in maize.Increasing density increased the CLH activity and decreased the Chl content,T1,GLAear,and GLA_(ear) duration.Under high density,appropriate N application reduced CLH activity,increased Chl content,prolonged T1,alleviated high-density-induced leaf senescence,and increased post-silking dry matter accumulation and grain yield.展开更多
Knowledge of the function of growth-regulating factors(GRFs)in sugarcane(Saccharum officinarum and S.spontaneum)growth and development could assist breeders in selecting desirable plant architectures.However,limited i...Knowledge of the function of growth-regulating factors(GRFs)in sugarcane(Saccharum officinarum and S.spontaneum)growth and development could assist breeders in selecting desirable plant architectures.However,limited information about GRFs is available in Saccharum due to their polyploidy.In this study,22 GRFs were identified in the two species and their conserved domains,gene structures,chromosome location,and synteny were characterized.GRF7 expression varied among tissues and responded to diurnal rhythm.SsGRF7-YFP was localized preferentially in the nucleus and appears to act as a transcriptional cofactor.SsGRF7 positively regulated the size and length of rice leaves,possibly by regulating cell size and plant hormones.Of seven potential transcription factors binding to the SsGRF7 promoter in S.spontaneum,four showed positive expression patterns,and two showed negative expression patterns relative to SsGRF7.展开更多
Two oligosaccharide fractions(MLO 2-1 and 2-2)were purified from enzymatic hydrolysate of mulberry leaf polysaccharide.The results of simulated digestion showed that MLO 2-2 was a digestible oligosaccharide,which coul...Two oligosaccharide fractions(MLO 2-1 and 2-2)were purified from enzymatic hydrolysate of mulberry leaf polysaccharide.The results of simulated digestion showed that MLO 2-2 was a digestible oligosaccharide,which could be degraded by human digestive juice;while MLO 2-1 possessed the non-digestible property in the upper gastrointestinal tract and performed the function by regulating the gut microbiota.Hence,MLO 2-1 was selected for the further analysis.The structure of MLO 2-1 was elucidated as follow:α-T-Glcp-(1→3)-β-Glcp-(1→5)-α-Araf-(1→5)-α-Araf-1→5)-α-Araf-(1→3)-α-(2-OAc)-Glcp-1.The in vitro fecal fermentation results showed that MLO 2-1 could modulate the composition of gut microbiota.Meanwhile,MLO 2-1 was effectively metabolized by fecal bacteria to produce lactate and short chain fatty acids,especially acetate and butyrate.The specific metabolic pathways of MLO 2-1 by gut microbiota were further illuminated.Gut microbiota analysis revealed that MLO 2-1 selectively promoted the growth of Ligilactobacillus murinus,a commensal bacterium presented a reduced level in T2DM mice.Animal experiments indicated that MLO 2-1 and L.murinus exhibited hypoglycemic activities.These results demonstrated that MLO 2-1 might alleviate T2DM by selectively accelerating the proliferation of L.murinus.展开更多
Olive trees are susceptible to a variety of diseases that can cause significant crop damage and economic losses.Early detection of these diseases is essential for effective management.We propose a novel transformed wa...Olive trees are susceptible to a variety of diseases that can cause significant crop damage and economic losses.Early detection of these diseases is essential for effective management.We propose a novel transformed wavelet,feature-fused,pre-trained deep learning model for detecting olive leaf diseases.The proposed model combines wavelet transforms with pre-trained deep-learning models to extract discriminative features from olive leaf images.The model has four main phases:preprocessing using data augmentation,three-level wavelet transformation,learning using pre-trained deep learning models,and a fused deep learning model.In the preprocessing phase,the image dataset is augmented using techniques such as resizing,rescaling,flipping,rotation,zooming,and contrasting.In wavelet transformation,the augmented images are decomposed into three frequency levels.Three pre-trained deep learning models,EfficientNet-B7,DenseNet-201,and ResNet-152-V2,are used in the learning phase.The models were trained using the approximate images of the third-level sub-band of the wavelet transform.In the fused phase,the fused model consists of a merge layer,three dense layers,and two dropout layers.The proposed model was evaluated using a dataset of images of healthy and infected olive leaves.It achieved an accuracy of 99.72%in the diagnosis of olive leaf diseases,which exceeds the accuracy of other methods reported in the literature.This finding suggests that our proposed method is a promising tool for the early detection of olive leaf diseases.展开更多
Auxin is throughout the entire life process of plants and is involved in the crosstalk with other hormones,yet its role in apple disease resistance remains unclear.In this study,we investigated the function of auxin/i...Auxin is throughout the entire life process of plants and is involved in the crosstalk with other hormones,yet its role in apple disease resistance remains unclear.In this study,we investigated the function of auxin/indole-3-acetic acid(IAA)gene Md IAA24 overexpression in enhancing apple resistance to Glomerella leaf spot(GLS)caused by Colletotrichum fructicola(Cf).Analysis revealed that,upon Cf infection,35S::Md IAA24 plants exhibited enhanced superoxide dismutase(SOD)and peroxidase(POD)activity,as well as a greater amount of glutathione(reduced form)and ascorbic acid accumulation,resulting in less H_(2)O_(2)and superoxide anion(O_(2)^(-))in apple leaves.Furthermore,35S::Md IAA24 plants produced more protocatechuic acid,proanthocyanidins B1,proanthocyanidins B2 and chlorogenic acid when infected with Cf.Following Cf infection,35S::Md IAA24 plants presented lower levels of IAA and jasmonic acid(JA),but higher levels of salicylic acid(SA),along with the expression of related genes.The overexpression of Md IAA24 was observed to enhance the activity of chitinase andβ-1,3-glucanase in Cfinfected leaves.The results indicated the ability of Md IAA24 to regulate the crosstalk between IAA,JA and SA,and to improve reactive oxygen species(ROS)scavenging and defense-related enzymes activity.This jointly contributed to GLS resistance in apple.展开更多
Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion...Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion on the networks of leaf traits in woody plants within remnant forest patches,thereby enhancing our understanding of plant adaptive strategies and contributing to the conservation of urban biodiversity.Methods:Our study examined woody plants within 120 sample plots across 15 remnant forest patches in Guiyang,China.We constructed leaf trait networks (LTNs) based on 26 anatomical,structural,and compositional leaf traits and assessed the effects of the spatiotemporal dynamics of urban expansion on these LTNs.Results and conclusions:Our results indicate that shrubs within these patches have greater average path lengths and diameters than trees.With increasing urban expansion intensity,we observed a rise in the edge density of the LTN-shrubs.Additionally,modularity within the networks of shrubs decreased as road density and urban expansion intensity increased,and increases in the average path length and average clustering coefficient for shrubs were observed with a rise in the composite terrain complexity index.Notably,patches subjected to‘leapfrog’expansion exhibited greater average patch length and diameter than those experiencing edge growth.Stomatal traits were found to have high degree centrality within these networks,signifying their substantial contribution to multiple functions.In urban remnant forests,shrubs bolster their resilience to variable environmental pressures by augmenting the complexity of their leaf trait networks.展开更多
Accurate diagnosis of apple leaf diseases is crucial for improving the quality of apple production and promoting the development of the apple industry. However, apple leaf diseases do not differ significantly from ima...Accurate diagnosis of apple leaf diseases is crucial for improving the quality of apple production and promoting the development of the apple industry. However, apple leaf diseases do not differ significantly from image texture and structural information. The difficulties in disease feature extraction in complex backgrounds slow the related research progress. To address the problems, this paper proposes an improved multi-scale inverse bottleneck residual network model based on a triplet parallel attention mechanism, which is built upon ResNet-50, while improving and combining the inception module and ResNext inverse bottleneck blocks, to recognize seven types of apple leaf(including six diseases of alternaria leaf spot, brown spot, grey spot, mosaic, rust, scab, and one healthy). First, the 3×3 convolutions in some of the residual modules are replaced by multi-scale residual convolutions, the convolution kernels of different sizes contained in each branch of the multi-scale convolution are applied to extract feature maps of different sizes, and the outputs of these branches are multi-scale fused by summing to enrich the output features of the images. Second, the global layer-wise dynamic coordinated inverse bottleneck structure is used to reduce the network feature loss. The inverse bottleneck structure makes the image information less lossy when transforming from different dimensional feature spaces. The fusion of multi-scale and layer-wise dynamic coordinated inverse bottlenecks makes the model effectively balances computational efficiency and feature representation capability, and more robust with a combination of horizontal and vertical features in the fine identification of apple leaf diseases. Finally, after each improved module, a triplet parallel attention module is integrated with cross-dimensional interactions among channels through rotations and residual transformations, which improves the parallel search efficiency of important features and the recognition rate of the network with relatively small computational costs while the dimensional dependencies are improved. To verify the validity of the model in this paper, we uniformly enhance apple leaf disease images screened from the public data sets of Plant Village, Baidu Flying Paddle, and the Internet. The final processed image count is 14,000. The ablation study, pre-processing comparison, and method comparison are conducted on the processed datasets. The experimental results demonstrate that the proposed method reaches 98.73% accuracy on the adopted datasets, which is 1.82% higher than the classical ResNet-50 model, and 0.29% better than the apple leaf disease datasets before preprocessing. It also achieves competitive results in apple leaf disease identification compared to some state-ofthe-art methods.展开更多
The purpose of this study was to characterize mulberry leaf instant tea(MLIT)powder prepared from the'Longsang No.1'(Morus abla L.cv.Longsang 1)mulberry leaves in Heilongjiang Province(China)and assess its obe...The purpose of this study was to characterize mulberry leaf instant tea(MLIT)powder prepared from the'Longsang No.1'(Morus abla L.cv.Longsang 1)mulberry leaves in Heilongjiang Province(China)and assess its obesity-preventing/relieving effects.A total of 174 compounds including quercetin,chlorogenic acid,1-deoxyecomycin(1-DNJ)related to antihyperlipidemia effects were identified from the MLIT powder.MLIT treatment reversed the Lee's index,fat coefficient,and serum biochemical parameters in both the obesity relieving and obesity preventing mice fed with high-fat diet.In the obesity relieving experiment,the relative abundance of Desulfovibrio in mouse feces decreased after both 0.5%and 1%MLIT treatments.In obesity preventing experiments,mouse with different amount of MLIT treatments showed increased relative abundance of Akkermansia,Bifidobacterium and Lactobacillus,while Deferribacteres,Desulfobacterota decreased.The beneficial bacteria in the intestinal tract of mice treated with MLIT increased.This study proved that MLIT had antihyperlipidemia potential via modulating intestinal microbiota in mice.展开更多
As an important rice disease, rice bacterial leaf blight (RBLB, caused by the bacterium Xanthomonas oryzae pv.oryzae), has become widespread in east China in recent years. Significant losses in rice yield occurred as ...As an important rice disease, rice bacterial leaf blight (RBLB, caused by the bacterium Xanthomonas oryzae pv.oryzae), has become widespread in east China in recent years. Significant losses in rice yield occurred as a result ofthe disease’s epidemic, making it imperative to monitor RBLB at a large scale. With the development of remotesensing technology, the broad-band sensors equipped with red-edge channels over multiple spatial resolutionsoffer numerous available data for large-scale monitoring of rice diseases. However, RBLB is characterized by rapiddispersal under suitable conditions, making it difficult to track the disease at a regional scale with a single sensorin practice. Therefore, it is necessary to identify or construct features that are effective across different sensors formonitoring RBLB. To achieve this goal, the spectral response of RBLB was first analyzed based on the canopyhyperspectral data. Using the relative spectral response (RSR) functions of four representative satellite or UAVsensors (i.e., Sentinel-2, GF-6, Planet, and Rededge-M) and the hyperspectral data, the corresponding broad-bandspectral data was simulated. According to a thorough band combination and sensitivity analysis, two novel spectralindices for monitoring RBLB that can be effective across multiple sensors (i.e., RBBRI and RBBDI) weredeveloped. An optimal feature set that includes the two novel indices and a classical vegetation index was formed.The capability of such a feature set in monitoring RBLB was assessed via FLDA and SVM algorithms. The resultdemonstrated that both constructed novel indices exhibited high sensitivity to the disease across multiple sensors.Meanwhile, the feature set yielded an overall accuracy above 90% for all sensors, which indicates its cross-sensorgenerality in monitoring RBLB. The outcome of this research permits disease monitoring with different remotesensing data over a large scale.展开更多
Soybean frogeye leaf spot(FLS) disease is a global disease affecting soybean yield, especially in the soybean growing area of Heilongjiang Province. In order to realize genomic selection breeding for FLS resistance of...Soybean frogeye leaf spot(FLS) disease is a global disease affecting soybean yield, especially in the soybean growing area of Heilongjiang Province. In order to realize genomic selection breeding for FLS resistance of soybean, least absolute shrinkage and selection operator(LASSO) regression and stepwise regression were combined, and a genomic selection model was established for 40 002 SNP markers covering soybean genome and relative lesion area of soybean FLS. As a result, 68 molecular markers controlling soybean FLS were detected accurately, and the phenotypic contribution rate of these markers reached 82.45%. In this study, a model was established, which could be used directly to evaluate the resistance of soybean FLS and to select excellent offspring. This research method could also provide ideas and methods for other plants to breeding in disease resistance.展开更多
BACKGROUND The investigation of plant-based therapeutic agents in medicinal plants has revealed their presence in the extracts and provides the vision to formulate novel techniques for drug therapy.Vitex negundo(V.neg...BACKGROUND The investigation of plant-based therapeutic agents in medicinal plants has revealed their presence in the extracts and provides the vision to formulate novel techniques for drug therapy.Vitex negundo(V.negundo),a perennial herb belonging to the Varbanaceae family,is extensively used in conventional medication.AIM To determine the existence of therapeutic components in leaf and callus extracts from wild V.negundo plants using gas chromatography-mass spectrometry(GCMS).METHODS In this study,we conducted GC-MS on wild plant leaf extracts and correlated the presence of constituents with those in callus extracts.Various growth regulators such as 6-benzylaminopurine(BAP),2,4-dichlorophenoxyacetic acid(2,4-D),α-naphthylacetic acid(NAA),and di-phenylurea(DPU)were added to plant leaves and in-vitro callus and grown on MS medium.RESULTS The results clearly indicated that the addition of BAP(2.0 mg/L),2,4-D(0.2 mg/mL),DPU(2.0 mg/L)and 2,4-D(0.2 mg/mL)in MS medium resulted in rapid callus development.The plant profile of Vitex extracts by GC-MS analysis showed that 24,10,and 14 bioactive constituents were detected in the methanolic extract of leaf,green callus and the methanolic extract of white loose callus,respectively.CONCLUSION Octadecadienoic acid,hexadecanoic acid and methyl ester were the major constituents in the leaf and callus methanolic extract.Octadecadienoic acid was the most common constituent in all samples.The maximum concentration of octadecadienoic acid in leaves,green callus and white loose callus was 21.93%,47.79%and 40.38%,respectively.These findings demonstrate that the concentration of octadecadienoic acid doubles in-vitro compared to in-vivo.In addition to octadecadienoic acid;butyric acid,benzene,1-methoxy-4-(1-propenyl),dospan,tridecanedialdehyde,methylcyclohexenylbutanol,chlorpyrifos,n-secondary terpene diester,anflunine and other important active compounds were also detected.All these components were only available in callus formed in-vitro.This study showed that the callus contained additional botanical characteristics compared with wild plants.Due to the presence of numerous bioactive compounds,the medical use of Vitex for various diseases has been accepted and the plant is considered an important source of therapeutics for research and development.展开更多
Technologies for reducing corn leaf burn caused by foliar spray of urea-ammonium nitrate (UAN) during the early growing season are limited. A field experiment was carried out to evaluate the effects of humic acid on c...Technologies for reducing corn leaf burn caused by foliar spray of urea-ammonium nitrate (UAN) during the early growing season are limited. A field experiment was carried out to evaluate the effects of humic acid on corn leaf burn caused by foliar spray of undiluted UAN solution on corn canopy at Jackson, TN in 2018. Thirteen treatments of the mixtures of UAN and humic acid were evaluated at V6 of corn with different UAN application rates and different UAN/humic acid ratios. Leaf burn during 1 2, 3, 4, 5, 6, 7, and 14 days after UAN foliar spray significantly differed between with or without humic acid addition. The addition of humic acid to UAN significantly reduced leaf burn at each UAN application rate (15, 25, and 35 gal/acre). The reduction of leaf burn was enhanced as the humic acid/UAN ratio went up from 10% to 30%. Leaf burn due to foliar application of UAN became severer with higher UAN rates. The linear regression of leaf burn 14 days after application with humic acid/UAN ratio was highly significant and negative. However, the linear regression of leaf burn 14 days after application with the UAN application rate was highly significant and positive. In conclusion, adding humic acid to foliar-applied UAN is beneficial for reducing corn leaf burn during the early growing season.展开更多
Independence among leaf economics,leaf hydraulics and leaf size confers plants great capability in adapting to heterogeneous environments.However,it remains unclear whether the independence of the leaf traits revealed...Independence among leaf economics,leaf hydraulics and leaf size confers plants great capability in adapting to heterogeneous environments.However,it remains unclear whether the independence of the leaf traits revealed across species still holds within species,especially under stressed conditions.Here,a suite of traits in these dimensions were measured in leaves and roots of a typical mangrove species,Ceriops tagal,which grows in habitats with a similar sunny and hot environment but different soil salinity in southern China.Compared with C.tagal under low soil salinity,C.tagal under high soil salinity had lower photosynthetic capacity,as indicated directly by a lower leaf nitrogen concentration and higher water use efficiency,and indirectly by a higher investment in defense function and thinner palisade tissue;had lower water transport capacity,as evidenced by thinner leaf minor veins and thinner root vessels;and also had much smaller single leaf area.Leaf economics,hydraulics and leaf size of the mangrove species appear to be coordinated as one trait dimension,which likely stemmed from covariation of soil water and nutrient availability along the salinity gradient.The intraspecific leaf trait relationship under a stressful environment is insightful for our understanding of plant adaption to the multifarious environments.展开更多
A collection representing the native range of pecan was planted at the US DA-ARS Southeastern Fruit and Tree Nut Research Station,Byron,GA.The collection(867 trees)is a valuable genetic resource for characterizing imp...A collection representing the native range of pecan was planted at the US DA-ARS Southeastern Fruit and Tree Nut Research Station,Byron,GA.The collection(867 trees)is a valuable genetic resource for characterizing important horticultural traits.Canopy density during leaf fall is important as the seasonal canopy dynamics provides insights to environmental cues and breeding potential of germplasm.The ability of visual raters to estimate canopy density on a subset of the provenance collection(76 trees)as an indicator of leaf shed during autumn along with image analysis values was explored.Mean canopy density using the image analysis software was less compared to visual estimates(11.9%vs 18.4%,respectively).At higher canopy densities,the raters overestimated foliage density,but overall agreement between raters and measured values was good(ρc=0.849 to 0.915),and inter-rater reliability was high(R^(2)=0.910 to 0.953).The provenance from Missouri(MOL),the northernmost provenance,had the lowest canopy density in November,and results show that the higher the latitude of the provenance,the lower the canopy density.Based on regression,the source provenance latitude explained 0.609 of the variation using image analysis,and0.551 to 0.640 when based on the rater estimates of canopy density.Visual assessment of pecan canopy density due to late season leaf fall for comparing pecan genotypes provides accurate and reliable estimates and could be used in future studies of the whole provenance collection.展开更多
基金financially supported by a grant of the National Natural Science Foundation of China(31670406)the Bagui Fellow scholarship(C33600992001)of Guangxi Zhuang Autonomous Region to KFC.
文摘Stomatal regulation is critical for mangroves to survive in the hyper-saline intertidal zone where water stress is severe and water availability is highly fluctuant.However,very little is known about the stomatal sensitivity to vapour pressure deficit(VPD)in mangroves,and its co-ordination with stomatal morphology and leaf hydraulic traits.We measured the stomatal response to a step increase in VPD in situ,stomatal anatomy,leaf hydraulic vulnerability and pressure-volume traits in nine true mangrove species of five families and collected the data of genome size.We aimed to answer two questions:(1)Does stomatal morphology influence stomatal dynamics in response to a high VPD in mangroves?with a consideration of possible influence of genome size on stomatal morphology;and(2)do leaf hydraulic traits influence stomatal sensitivity to VPD in mangroves?We found that the stomata of mangrove plants were highly sensitive to a step rise in VPD and the stomatal responses were directly affected by stomatal anatomy and hydraulic traits.Smaller,denser stomata was correlated with faster stomatal closure at high VPD across the species of Rhizophoraceae,and stomata size negatively and vein density positively correlated with genome size.Less negative leaf osmotic pressure at the full turgor(πo)was related to higher operating steady-state stomatal conductance(gs);and a higher leaf capacitance(Cleaf)and more embolism resistant leaf xylem were associated with slower stomatal responses to an increase in VPD.In addition,stomatal responsiveness to VPD was indirectly affected by leaf morphological traits,which were affected by site salinity and consequently leaf water status.Our results demonstrate that mangroves display a unique relationship between genome size,stomatal size and vein packing,and that stomatal responsiveness to VPD is regulated by leaf hydraulic traits and stomatal morphology.Our work provides a quantitative framework to better understand of stomatal regulation in mangroves in an environment with high salinity and dynamic water availability.
基金financially supported by the Deanship of Scientific Research,Qassim University,Saudi Arabia for funding the publication of this project.
文摘The guava plant has achieved viable significance in subtropics and tropics owing to its flexibility to climatic environments,soil conditions and higher human consumption.It is cultivated in vast areas of Asian and Non-Asian countries,including Pakistan.The guava plant is vulnerable to diseases,specifically the leaves and fruit,which result in massive crop and profitability losses.The existing plant leaf disease detection techniques can detect only one disease from a leaf.However,a single leaf may contain symptoms of multiple diseases.This study has proposed a hybrid deep learning-based framework for the real-time detection of multiple diseases from a single guava leaf in several steps.Firstly,Guava Infected Patches Modified MobileNetV2 and U-Net(GIP-MU-NET)has been proposed to segment the infected guava patches.The proposed model consists of modified MobileNetv2 as an encoder,and the U-Net model’s up-sampling layers are used as a decoder part.Secondly,the Guava Leaf SegmentationModel(GLSM)is proposed to segment the healthy and infected leaves.In the final step,the Guava Multiple Leaf Diseases Detection(GMLDD)model based on the YOLOv5 model detects various diseases from a guava leaf.Two self-collected datasets(the Guava Patches Dataset and the Guava Leaf Diseases Dataset)are used for training and validation.The proposed method detected the various defects,including five distinct classes,i.e.,anthracnose,insect attack,nutrition deficiency,wilt,and healthy.On average,the GIP-MU-Net model achieved 92.41%accuracy,the GLSM gained 83.40%accuracy,whereas the proposed GMLDD technique achieved 73.3%precision,73.1%recall,71.0%mAP@0.5 and 50.3 mAP@0.5:0.95 scores for all the aforesaid classes.
基金supported by the Nanfan Special Project of Chinese Academy of Agricultural Sciences (Grant No. ZDXM2315)the National Natural Science Foundation of China (Grant Nos. 32372125, 31861143006, and 32188102)+2 种基金Special Support Program of Chinese Academy of Agricultural Sciences (Grant NO. NKYCLJ-C-2021-015)Specific Research Fund of the Innovation Platform for Academicians of Hainan Province2023 College Student Innovation and Entrepreneurship Project of Jiangxi Agricultural University, China (Grant No. S202310410095)
文摘The morphological development of rice(Oryza sativa L.)leaves is closely related to plant architecture,physiological activities,and resistance.However,it is unclear whether there is a co-regulatory relationship between the morphological development of leaves and adaptation to drought environment.In this study,a drought-sensitive,roll-enhanced,and narrow-leaf mutant(renl1)was induced from a semi-rolled leaf mutant(srl1)by ethyl methane sulfonate(EMS),which was obtained from Nipponbare(NPB)through EMS.Map-based cloning and functional validation showed that RENL1 encodes a cellulose synthase,allelic to NRL1/OsCLSD4.The RENL1 mutation resulted in reduced vascular bundles,vesicular cells,cellulose,and hemicellulose contents in cell walls,diminishing the water-holding capacity of leaves.In addition,the root system of the renl1 mutant was poorly developed and its ability to scavenge reactive oxygen species(ROS)was decreased,leading to an increase in ROS after drought stress.Meanwhile,genetic results showed that RENL1 and SRL1 synergistically regulated cell wall components.Our results revealed a theoretical basis for further elucidating the molecular regulation mechanism of cellulose on rice drought tolerance,and provided a new genetic resource for enhancing the synergistic regulation network of plant type and stress resistance,thereby realizing simultaneous improvement of multiple traits in rice.
基金This work was supported by grants from the construction and operation of the Food Nutrition and Health Research Center of Guangdong Academy of Agricultural Sciences,China(XTXM 202205)the earmarked fund for CARS-10Sweetpotato,and the Guangdong Modern Agro-industry Technology Research System,China(2022KJ111).
文摘Sweet potato leaf tips have high nutritional value,and exploring the differences in the metabolic profiles of leaf tips among different sweet potato varieties can provide information to improve their qualities.In this study,a UPLC-Q-Exactive Orbitrap/MS-based untargeted metabolomics method was used to evaluate the metabolites in leaf tips of 32 sweet potato varieties.Three varieties with distinct overall metabolic profiles(A01,A02,and A03),two varieties with distinct profiles of phenolic acids(A20 and A18),and three varieties with distinct profiles of flavonoids(A05,A12,and A16)were identified.In addition,a total of 163 and 29 differentially expressed metabolites correlated with the color and leaf shape of sweet potato leaf tips,respectively,were identified through morphological characterization.Group comparison analysis of the phenotypic traits and a metabolite-phenotypic trait correlation analysis indicated that the color differences of sweet potato leaf tips were markedly associated with flavonoids.Also,the level of polyphenols was correlated with the leaf shape of sweet potato leaf tips,with lobed leaf types having higher levels of polyphenols than the entire leaf types.The findings on the metabolic profiles and differentially expressed metabolites associated with the morphology of sweet potato leaf tips can provide useful information for breeding sweet potato varieties with higher nutritional value.
基金supported by the Doctor Foundation of Gansu Academy of Agricultural Sciences,China(2020GAAS33)the Young Science and Technology Lifting Engineering Talents in Gansu Province,China(2020-18)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2017-ICS)。
文摘Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.
基金financially supported by the National Key Research and Development Program of China(2022YFD190160304)Natural Science Foundation of Sichuan Province(2022NSFSC0013)+1 种基金Sichuan Maize Innovation Team Construction Project(SCCXTD-2022-02)National Key Research and Development Program of China(2018YFD0301206)。
文摘Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the activities of Chl a-degrading enzymes after silking,and the post-silking dry matter accumulation and grain yield under multiple planting densities and N fertilization rates.The dynamic change of GLA_(ear)after silking fitted to the logistic model,and the GLA_(ear) duration and the GLAearat 42 d after silking were affected mainly by the duration of the initial senescence period(T_(1))which was a key factor of the leaf senescence.The average chlorophyllase(CLH)activity was 8.3 times higher than pheophytinase activity and contributed most to the Chl content,indicating that CLH is a key enzyme for degrading Chl a in maize.Increasing density increased the CLH activity and decreased the Chl content,T1,GLAear,and GLA_(ear) duration.Under high density,appropriate N application reduced CLH activity,increased Chl content,prolonged T1,alleviated high-density-induced leaf senescence,and increased post-silking dry matter accumulation and grain yield.
基金funded by the National Key Research and Development Program(2021YFF1000101 and 2021YFF1000104)the National Natural Science Foundation of China(32272196)the Sugarcane Research Foundation of Guangxi University(2022GZB007)。
文摘Knowledge of the function of growth-regulating factors(GRFs)in sugarcane(Saccharum officinarum and S.spontaneum)growth and development could assist breeders in selecting desirable plant architectures.However,limited information about GRFs is available in Saccharum due to their polyploidy.In this study,22 GRFs were identified in the two species and their conserved domains,gene structures,chromosome location,and synteny were characterized.GRF7 expression varied among tissues and responded to diurnal rhythm.SsGRF7-YFP was localized preferentially in the nucleus and appears to act as a transcriptional cofactor.SsGRF7 positively regulated the size and length of rice leaves,possibly by regulating cell size and plant hormones.Of seven potential transcription factors binding to the SsGRF7 promoter in S.spontaneum,four showed positive expression patterns,and two showed negative expression patterns relative to SsGRF7.
基金the Key Research and Development Program of Yunnan Province(No.202202AE090023)Key Research and Development Program of Guangdong Province(No.2022B0202040002+8 种基金2022B0202050001)the Key Laboratory of Green Processing and Intelligent Manufacturing of Lingnan Specialty Food,Ministry of Agriculturethe Heyuan Branch,Guangdong Laboratory for Lingnan Modern Agriculture Project(No.DT20220026)Talent Introduction Program of Guangdong Academy of Agricultural Sciences(No.R2022YJ-YB3004)the Basic and Applied Basic Research Project of Guangdong Province(No.2022A15151102272023A1515012386)the Science and Technology Planning Project of Guangzhou(No.2023A04J0828)the Guangdong Provincial Special Fund for Modern Agriculture Industry Technology Innovation Teams(No.202109TD)the Special Fund Project for Teachers’Scientific and Technological Achievements Transformation in Shunde Innovation Park,National University Science Park,South China University of Technology(No.KJYS2021KZ05)for their financial support。
文摘Two oligosaccharide fractions(MLO 2-1 and 2-2)were purified from enzymatic hydrolysate of mulberry leaf polysaccharide.The results of simulated digestion showed that MLO 2-2 was a digestible oligosaccharide,which could be degraded by human digestive juice;while MLO 2-1 possessed the non-digestible property in the upper gastrointestinal tract and performed the function by regulating the gut microbiota.Hence,MLO 2-1 was selected for the further analysis.The structure of MLO 2-1 was elucidated as follow:α-T-Glcp-(1→3)-β-Glcp-(1→5)-α-Araf-(1→5)-α-Araf-1→5)-α-Araf-(1→3)-α-(2-OAc)-Glcp-1.The in vitro fecal fermentation results showed that MLO 2-1 could modulate the composition of gut microbiota.Meanwhile,MLO 2-1 was effectively metabolized by fecal bacteria to produce lactate and short chain fatty acids,especially acetate and butyrate.The specific metabolic pathways of MLO 2-1 by gut microbiota were further illuminated.Gut microbiota analysis revealed that MLO 2-1 selectively promoted the growth of Ligilactobacillus murinus,a commensal bacterium presented a reduced level in T2DM mice.Animal experiments indicated that MLO 2-1 and L.murinus exhibited hypoglycemic activities.These results demonstrated that MLO 2-1 might alleviate T2DM by selectively accelerating the proliferation of L.murinus.
文摘Olive trees are susceptible to a variety of diseases that can cause significant crop damage and economic losses.Early detection of these diseases is essential for effective management.We propose a novel transformed wavelet,feature-fused,pre-trained deep learning model for detecting olive leaf diseases.The proposed model combines wavelet transforms with pre-trained deep-learning models to extract discriminative features from olive leaf images.The model has four main phases:preprocessing using data augmentation,three-level wavelet transformation,learning using pre-trained deep learning models,and a fused deep learning model.In the preprocessing phase,the image dataset is augmented using techniques such as resizing,rescaling,flipping,rotation,zooming,and contrasting.In wavelet transformation,the augmented images are decomposed into three frequency levels.Three pre-trained deep learning models,EfficientNet-B7,DenseNet-201,and ResNet-152-V2,are used in the learning phase.The models were trained using the approximate images of the third-level sub-band of the wavelet transform.In the fused phase,the fused model consists of a merge layer,three dense layers,and two dropout layers.The proposed model was evaluated using a dataset of images of healthy and infected olive leaves.It achieved an accuracy of 99.72%in the diagnosis of olive leaf diseases,which exceeds the accuracy of other methods reported in the literature.This finding suggests that our proposed method is a promising tool for the early detection of olive leaf diseases.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFD1000307)the National Natural Science Foundation of China(Grant No.32172529)+2 种基金the Special Funds for Major Scientific and Technological Innovation from Shaanxi Province(Grant No.2020zdzx03-0101)the Earmarked Fund for China Agriculture Research System(Grant No.CARS-27)China Postdoctoral Science Foundation(Grant Nos.2017M610657,2018T111108)。
文摘Auxin is throughout the entire life process of plants and is involved in the crosstalk with other hormones,yet its role in apple disease resistance remains unclear.In this study,we investigated the function of auxin/indole-3-acetic acid(IAA)gene Md IAA24 overexpression in enhancing apple resistance to Glomerella leaf spot(GLS)caused by Colletotrichum fructicola(Cf).Analysis revealed that,upon Cf infection,35S::Md IAA24 plants exhibited enhanced superoxide dismutase(SOD)and peroxidase(POD)activity,as well as a greater amount of glutathione(reduced form)and ascorbic acid accumulation,resulting in less H_(2)O_(2)and superoxide anion(O_(2)^(-))in apple leaves.Furthermore,35S::Md IAA24 plants produced more protocatechuic acid,proanthocyanidins B1,proanthocyanidins B2 and chlorogenic acid when infected with Cf.Following Cf infection,35S::Md IAA24 plants presented lower levels of IAA and jasmonic acid(JA),but higher levels of salicylic acid(SA),along with the expression of related genes.The overexpression of Md IAA24 was observed to enhance the activity of chitinase andβ-1,3-glucanase in Cfinfected leaves.The results indicated the ability of Md IAA24 to regulate the crosstalk between IAA,JA and SA,and to improve reactive oxygen species(ROS)scavenging and defense-related enzymes activity.This jointly contributed to GLS resistance in apple.
基金funded by the National Natural Science Foundation of China (No.32360418)the Guizhou Provincial Basic Research Program (Natural Science)(No.QianKeHeJiChu-ZK[2024]YiBan022)。
文摘Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion on the networks of leaf traits in woody plants within remnant forest patches,thereby enhancing our understanding of plant adaptive strategies and contributing to the conservation of urban biodiversity.Methods:Our study examined woody plants within 120 sample plots across 15 remnant forest patches in Guiyang,China.We constructed leaf trait networks (LTNs) based on 26 anatomical,structural,and compositional leaf traits and assessed the effects of the spatiotemporal dynamics of urban expansion on these LTNs.Results and conclusions:Our results indicate that shrubs within these patches have greater average path lengths and diameters than trees.With increasing urban expansion intensity,we observed a rise in the edge density of the LTN-shrubs.Additionally,modularity within the networks of shrubs decreased as road density and urban expansion intensity increased,and increases in the average path length and average clustering coefficient for shrubs were observed with a rise in the composite terrain complexity index.Notably,patches subjected to‘leapfrog’expansion exhibited greater average patch length and diameter than those experiencing edge growth.Stomatal traits were found to have high degree centrality within these networks,signifying their substantial contribution to multiple functions.In urban remnant forests,shrubs bolster their resilience to variable environmental pressures by augmenting the complexity of their leaf trait networks.
基金supported in part by the General Program Hunan Provincial Natural Science Foundation of 2022,China(2022JJ31022)the Undergraduate Education Reform Project of Hunan Province,China(HNJG-20210532)the National Natural Science Foundation of China(62276276)。
文摘Accurate diagnosis of apple leaf diseases is crucial for improving the quality of apple production and promoting the development of the apple industry. However, apple leaf diseases do not differ significantly from image texture and structural information. The difficulties in disease feature extraction in complex backgrounds slow the related research progress. To address the problems, this paper proposes an improved multi-scale inverse bottleneck residual network model based on a triplet parallel attention mechanism, which is built upon ResNet-50, while improving and combining the inception module and ResNext inverse bottleneck blocks, to recognize seven types of apple leaf(including six diseases of alternaria leaf spot, brown spot, grey spot, mosaic, rust, scab, and one healthy). First, the 3×3 convolutions in some of the residual modules are replaced by multi-scale residual convolutions, the convolution kernels of different sizes contained in each branch of the multi-scale convolution are applied to extract feature maps of different sizes, and the outputs of these branches are multi-scale fused by summing to enrich the output features of the images. Second, the global layer-wise dynamic coordinated inverse bottleneck structure is used to reduce the network feature loss. The inverse bottleneck structure makes the image information less lossy when transforming from different dimensional feature spaces. The fusion of multi-scale and layer-wise dynamic coordinated inverse bottlenecks makes the model effectively balances computational efficiency and feature representation capability, and more robust with a combination of horizontal and vertical features in the fine identification of apple leaf diseases. Finally, after each improved module, a triplet parallel attention module is integrated with cross-dimensional interactions among channels through rotations and residual transformations, which improves the parallel search efficiency of important features and the recognition rate of the network with relatively small computational costs while the dimensional dependencies are improved. To verify the validity of the model in this paper, we uniformly enhance apple leaf disease images screened from the public data sets of Plant Village, Baidu Flying Paddle, and the Internet. The final processed image count is 14,000. The ablation study, pre-processing comparison, and method comparison are conducted on the processed datasets. The experimental results demonstrate that the proposed method reaches 98.73% accuracy on the adopted datasets, which is 1.82% higher than the classical ResNet-50 model, and 0.29% better than the apple leaf disease datasets before preprocessing. It also achieves competitive results in apple leaf disease identification compared to some state-ofthe-art methods.
基金supported by the Natural Science Foundation of Heilongjiang Province (LH2021C075)Key Laboratory of Functional Inorganic Material Chemistry (Heilongjiang University),Ministry of Education。
文摘The purpose of this study was to characterize mulberry leaf instant tea(MLIT)powder prepared from the'Longsang No.1'(Morus abla L.cv.Longsang 1)mulberry leaves in Heilongjiang Province(China)and assess its obesity-preventing/relieving effects.A total of 174 compounds including quercetin,chlorogenic acid,1-deoxyecomycin(1-DNJ)related to antihyperlipidemia effects were identified from the MLIT powder.MLIT treatment reversed the Lee's index,fat coefficient,and serum biochemical parameters in both the obesity relieving and obesity preventing mice fed with high-fat diet.In the obesity relieving experiment,the relative abundance of Desulfovibrio in mouse feces decreased after both 0.5%and 1%MLIT treatments.In obesity preventing experiments,mouse with different amount of MLIT treatments showed increased relative abundance of Akkermansia,Bifidobacterium and Lactobacillus,while Deferribacteres,Desulfobacterota decreased.The beneficial bacteria in the intestinal tract of mice treated with MLIT increased.This study proved that MLIT had antihyperlipidemia potential via modulating intestinal microbiota in mice.
基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA28010500)National Natural Science Foundation of China(Grant Nos.42371385,42071420)Zhejiang Provincial Natural Science Foundation of China(Grant No.LTGN23D010002).
文摘As an important rice disease, rice bacterial leaf blight (RBLB, caused by the bacterium Xanthomonas oryzae pv.oryzae), has become widespread in east China in recent years. Significant losses in rice yield occurred as a result ofthe disease’s epidemic, making it imperative to monitor RBLB at a large scale. With the development of remotesensing technology, the broad-band sensors equipped with red-edge channels over multiple spatial resolutionsoffer numerous available data for large-scale monitoring of rice diseases. However, RBLB is characterized by rapiddispersal under suitable conditions, making it difficult to track the disease at a regional scale with a single sensorin practice. Therefore, it is necessary to identify or construct features that are effective across different sensors formonitoring RBLB. To achieve this goal, the spectral response of RBLB was first analyzed based on the canopyhyperspectral data. Using the relative spectral response (RSR) functions of four representative satellite or UAVsensors (i.e., Sentinel-2, GF-6, Planet, and Rededge-M) and the hyperspectral data, the corresponding broad-bandspectral data was simulated. According to a thorough band combination and sensitivity analysis, two novel spectralindices for monitoring RBLB that can be effective across multiple sensors (i.e., RBBRI and RBBDI) weredeveloped. An optimal feature set that includes the two novel indices and a classical vegetation index was formed.The capability of such a feature set in monitoring RBLB was assessed via FLDA and SVM algorithms. The resultdemonstrated that both constructed novel indices exhibited high sensitivity to the disease across multiple sensors.Meanwhile, the feature set yielded an overall accuracy above 90% for all sensors, which indicates its cross-sensorgenerality in monitoring RBLB. The outcome of this research permits disease monitoring with different remotesensing data over a large scale.
基金Supported by the National Key Research and Development Program of China(2021YFD1201103-01-05)。
文摘Soybean frogeye leaf spot(FLS) disease is a global disease affecting soybean yield, especially in the soybean growing area of Heilongjiang Province. In order to realize genomic selection breeding for FLS resistance of soybean, least absolute shrinkage and selection operator(LASSO) regression and stepwise regression were combined, and a genomic selection model was established for 40 002 SNP markers covering soybean genome and relative lesion area of soybean FLS. As a result, 68 molecular markers controlling soybean FLS were detected accurately, and the phenotypic contribution rate of these markers reached 82.45%. In this study, a model was established, which could be used directly to evaluate the resistance of soybean FLS and to select excellent offspring. This research method could also provide ideas and methods for other plants to breeding in disease resistance.
文摘BACKGROUND The investigation of plant-based therapeutic agents in medicinal plants has revealed their presence in the extracts and provides the vision to formulate novel techniques for drug therapy.Vitex negundo(V.negundo),a perennial herb belonging to the Varbanaceae family,is extensively used in conventional medication.AIM To determine the existence of therapeutic components in leaf and callus extracts from wild V.negundo plants using gas chromatography-mass spectrometry(GCMS).METHODS In this study,we conducted GC-MS on wild plant leaf extracts and correlated the presence of constituents with those in callus extracts.Various growth regulators such as 6-benzylaminopurine(BAP),2,4-dichlorophenoxyacetic acid(2,4-D),α-naphthylacetic acid(NAA),and di-phenylurea(DPU)were added to plant leaves and in-vitro callus and grown on MS medium.RESULTS The results clearly indicated that the addition of BAP(2.0 mg/L),2,4-D(0.2 mg/mL),DPU(2.0 mg/L)and 2,4-D(0.2 mg/mL)in MS medium resulted in rapid callus development.The plant profile of Vitex extracts by GC-MS analysis showed that 24,10,and 14 bioactive constituents were detected in the methanolic extract of leaf,green callus and the methanolic extract of white loose callus,respectively.CONCLUSION Octadecadienoic acid,hexadecanoic acid and methyl ester were the major constituents in the leaf and callus methanolic extract.Octadecadienoic acid was the most common constituent in all samples.The maximum concentration of octadecadienoic acid in leaves,green callus and white loose callus was 21.93%,47.79%and 40.38%,respectively.These findings demonstrate that the concentration of octadecadienoic acid doubles in-vitro compared to in-vivo.In addition to octadecadienoic acid;butyric acid,benzene,1-methoxy-4-(1-propenyl),dospan,tridecanedialdehyde,methylcyclohexenylbutanol,chlorpyrifos,n-secondary terpene diester,anflunine and other important active compounds were also detected.All these components were only available in callus formed in-vitro.This study showed that the callus contained additional botanical characteristics compared with wild plants.Due to the presence of numerous bioactive compounds,the medical use of Vitex for various diseases has been accepted and the plant is considered an important source of therapeutics for research and development.
文摘Technologies for reducing corn leaf burn caused by foliar spray of urea-ammonium nitrate (UAN) during the early growing season are limited. A field experiment was carried out to evaluate the effects of humic acid on corn leaf burn caused by foliar spray of undiluted UAN solution on corn canopy at Jackson, TN in 2018. Thirteen treatments of the mixtures of UAN and humic acid were evaluated at V6 of corn with different UAN application rates and different UAN/humic acid ratios. Leaf burn during 1 2, 3, 4, 5, 6, 7, and 14 days after UAN foliar spray significantly differed between with or without humic acid addition. The addition of humic acid to UAN significantly reduced leaf burn at each UAN application rate (15, 25, and 35 gal/acre). The reduction of leaf burn was enhanced as the humic acid/UAN ratio went up from 10% to 30%. Leaf burn due to foliar application of UAN became severer with higher UAN rates. The linear regression of leaf burn 14 days after application with humic acid/UAN ratio was highly significant and negative. However, the linear regression of leaf burn 14 days after application with the UAN application rate was highly significant and positive. In conclusion, adding humic acid to foliar-applied UAN is beneficial for reducing corn leaf burn during the early growing season.
基金This study was funded by the National Natural Science Foundation of China(32171746,31870522 and 31670550)Special Foundation for National Science and Technology Basic Research Program of China(2019FY101300)the Scientific Research Foundation of Henan Agricultural University(30500854).
文摘Independence among leaf economics,leaf hydraulics and leaf size confers plants great capability in adapting to heterogeneous environments.However,it remains unclear whether the independence of the leaf traits revealed across species still holds within species,especially under stressed conditions.Here,a suite of traits in these dimensions were measured in leaves and roots of a typical mangrove species,Ceriops tagal,which grows in habitats with a similar sunny and hot environment but different soil salinity in southern China.Compared with C.tagal under low soil salinity,C.tagal under high soil salinity had lower photosynthetic capacity,as indicated directly by a lower leaf nitrogen concentration and higher water use efficiency,and indirectly by a higher investment in defense function and thinner palisade tissue;had lower water transport capacity,as evidenced by thinner leaf minor veins and thinner root vessels;and also had much smaller single leaf area.Leaf economics,hydraulics and leaf size of the mangrove species appear to be coordinated as one trait dimension,which likely stemmed from covariation of soil water and nutrient availability along the salinity gradient.The intraspecific leaf trait relationship under a stressful environment is insightful for our understanding of plant adaption to the multifarious environments.
基金supported by the USDA-ARS through CRIS project 6606-21220-014–00Dthe National Institute of Food and Agriculture–Specialty Crops Research Initiative grant 2016-51181-25408“Coordinated development of genetic tools for pecan”。
文摘A collection representing the native range of pecan was planted at the US DA-ARS Southeastern Fruit and Tree Nut Research Station,Byron,GA.The collection(867 trees)is a valuable genetic resource for characterizing important horticultural traits.Canopy density during leaf fall is important as the seasonal canopy dynamics provides insights to environmental cues and breeding potential of germplasm.The ability of visual raters to estimate canopy density on a subset of the provenance collection(76 trees)as an indicator of leaf shed during autumn along with image analysis values was explored.Mean canopy density using the image analysis software was less compared to visual estimates(11.9%vs 18.4%,respectively).At higher canopy densities,the raters overestimated foliage density,but overall agreement between raters and measured values was good(ρc=0.849 to 0.915),and inter-rater reliability was high(R^(2)=0.910 to 0.953).The provenance from Missouri(MOL),the northernmost provenance,had the lowest canopy density in November,and results show that the higher the latitude of the provenance,the lower the canopy density.Based on regression,the source provenance latitude explained 0.609 of the variation using image analysis,and0.551 to 0.640 when based on the rater estimates of canopy density.Visual assessment of pecan canopy density due to late season leaf fall for comparing pecan genotypes provides accurate and reliable estimates and could be used in future studies of the whole provenance collection.