Comparison of Genetic Diversity Between Local Cultivated Aromatic and Non-aromatic Rice in Yunnan Province

[ Objective] The genetic diversity of the local cultivated aromatic rice and non-aromatic rice in Yunnan Province were compared to provide further genetic resources for breeding practice. [Method] Genetic diversity of 10 aromatic rice and 45 non-aromatic rice were analyzed by 64 SSR primers covered on 12 rice chromosomes. [ Result] Per locus 5.44 and 7.98 alleles in average were detected, ranging from 2 to 12 and from 2 to 17 in aromatic and non-aromatic rice, respectively. Average genetic multiplicity index（Hs） was 0.46 and 0.67 respectively. The average polymorphism information content （PIC） was 0.43 and 0.58 in aromatic and non-aromatic rice respectively. [ Conclusion] The results indicated that genetic diversity was higher in non-aromatic rice than in aromatic rice.

Effects of Paclobutrazol Seed Soaking on Non-Structural Carbohydrate and Grain Enrichment in Direct-Seeded Rice

The yield of direct-seeded rice(DSR)was constrained by inadequate grain filling.Recent studies have indicated that paclobutrazol application plays a significant role in enhancing crop agronomic traits and increasing yield.This study aimed to examine the effects of paclobutrazol seed soaking(PSS)on non-structural carbohydrate accumulation and grain enrichment in DSR,potentially providing a theoretical foundation for achieving high-yield DSR cultivation.The experiment utilized two rice varieties,Jiyujing(JYJ)and Jijing305(JJ305),with seeds soaked in paclobutrazol concentrations of 0 mg L−1 and 100 mg L−1.PSS demonstrated increased chlorophyll content,net photosynthetic rate,and leaf area,as well as an extended photosynthetic function period during the filling stage.It also elevated soluble sugar and starch contents in the flag leaf(during the filling stage)and stem sheath(after heading),decreased starch content in the top panicle while increasing it in the middle and lower panicle during the filling stage,and enhanced spikelet per unit area and seed setting rate,thereby improving DSR yield.In conclusion,PSS enhanced the photosynthetic capacity of DSR during the filling stage,coordinated the filling process of superior and inferior grains,maintained source-sink balance,and facilitated stable and orderly filling,ultimately resulting in improved yield.

Breeding for Heat Tolerant Aromatic Rice Varieties and Identification of Novel QTL Regions Associated with Heat Tolerance During Reproductive Phase by QTL-Seq

Extremely high temperatures resulting from climate change have become a major challenge for increasing rice production.Therefore,our objective was to develop heat-tolerant aromatic rice varieties using the pedigree method,focusing on selecting for seed-setting ability under extremely high temperatures along with the use of single nucleotide polymorphism/insertion and deletion(SNP/InDel)markers to improve aromatic properties and grain quality.Furthermore,the QTL-seq approach was utilized to identify QTLs for seed-setting rate in an F2 population subjected to heat stress.The candidate QTL regions were then aligned to confirm SNPs/InDels in synonymous F7 candidate heat-tolerant lines.The results revealed that four promising lines,namely 84-7-1-9,84-7-1-10,159-3-3-1,and 159-3-3-10,were classified as heat-tolerant with low amylose content.In addition,lines 84-7-1-9 and 84-7-1-10 were identified as aromatic rice encompassing the aroma gene(badh2).Regarding the QTL-seq results,the qSF2.1 region ranged from 311051 to 3929422 bp on chromosome 2,was identified based on the highest contrasting SNP index between the heat-susceptible and tolerant bulks.The candidate genes within this region include two genes related to heat shock proteins,three genes associated with pollen fertility,and four genes involved in heat stress and other abiotic stress responses.These genes are proposed as potential candidates for heat tolerance and could serve as targets in rice breeding programs aimed at enhancing heat tolerance.

Understanding Investigational Perspective of Antioxidant and Antibacterial Properties of Rice

Whole-grain rice has gained significant attention for its potential health benefits,particularly because of its antioxidant and antibacterial properties.Despite this growing interest,there remains a pressing need for a comprehensive evaluation of the methods used to analyze these bioactive compounds,considering the diversity of rice types and the influence of environmental factors.This review aims to provide an in-depth overview of recent analytical methods,particularly those employed over the last five years,to assess the antioxidant and antibacterial properties of rice.It focuses on commonly used antioxidant assays,such as the 2,2-diphenyl-1-picrylhydrazyl(DPPH)radical scavenging activity assay,which encompasses both single electron transfer and hydrogen atom transfer mechanisms.Other antioxidant assays are also discussed,alongside methods used to evaluate antibacterial properties,including disc diffusion,well diffusion,broth or agar dilution,and advanced techniques such as flow cytofluorometric and bioluminescent assays.The review further explores the bacterial strains most frequently studied,including Bacillus cereus,Listeria monocytogenes,Escherichia coli,and Salmonella species.It highlights the key techniques and parameters employed to ascertain and quantify the antioxidant and antibacterial potential of rice,while critically analysing the strengths and limitations of these approaches.By synthesizing current methods and offering insights into their application,this review can be served as a guide for future research aimed at standardizing and improving the assessment of rice’s bioactive properties,paving the way for broader scientific and practical applications.

Small auxin-up RNA gene OsSAUR33 promotes seed aging tolerance in rice

Seed aging tolerance during storage is generally an important trait for crop production, yet the role of small auxin-up RNA genes in conferring seed aging tolerance is largely unknown in rice. In this study, one small auxin-up RNA gene, OsSAUR33, was found to be involved in the regulation of seed aging tolerance in rice. The expression of OsSAUR33 was significantly induced in aged seeds compared with unaged seeds during the seed germination phase. Accordingly, the disruption of OsSAUR33 significantly reduced seed vigor compared to the wild type(WT) in response to natural storage or artificial aging treatments. The rice OsSAUR33 gene promotes the vigor of aged seeds by enhancing their reactive oxygen species(ROS) level during seed germination, and the accumulation of ROS was significantly delayed in the aged seeds of Ossaur33 mutants in comparison with WT during seed germination. Hydrogen peroxide(H_(2)O_(2)) treatments promoted the vigor of aged seeds in various rice varieties. Our results provide timely theoretical and technical insights for the trait improvement of seed aging tolerance in rice.

Disruption of Energy Metabolism and Reactive Oxygen Species Homeostasis in Honglian Type-Cytoplasmic Male Sterility(HL-CMS)Rice Pollen

Honglian type-cytoplasmic male sterility(HL-CMS)is caused by the inter-communication between the nucleus and mitochondria.However,the mechanisms by which sterility genes regulate metabolic alterations and changes in mitochondrial morphology in the pollen of HL-CMS remain unclear.In this study,we compared the morphological differences between the pollen of the male sterile line YA and the near-isogenic line NIL-Rf6 using hematoxylin-eosin staining and 4ʹ,6-diamidino-2-phenylindole(DAPI)staining.HL-CMS is characterized by gametophytic sterility,where the aborted pollen grains are empty,and the tapetal layer remains intact.Transmission electron microscopy was employed to observe mitochondrial morphological changes at the microspore stage,revealing significant mitochondrial alterations,characterized by the formation of'large spherical mitochondria',occurred at the binucleate stage in the YA line.Additionally,metabolomics analysis revealed decreased levels of metabolites associated with the carbohydrate and flavonoid pathways.Notably,the decrease in flavonoids was found to contribute to an elevation in reactive oxygen species(ROS)levels.Therefore,we propose a model in which rice fertility is modulated by the levels of pollen carbohydrates and flavonoid metabolites,with impaired mitochondrial energy production and reduced flavonoid biosynthesis as the main causes of ROS accumulation and pollen abortion in rice.

Expanding Viral Diversity in Rice Fields by Next-Generation Sequencing

In rice fields,rice plants usually grow alongside wild weeds and are attacked by various invertebrate species.Viruses are abundant in plants and invertebrates,playing crucial ecological roles in controlling microbial abundance and maintaining community structures.To date,only 16 rice viruses have been documented in rice-growing regions.These viruses pose serious threats to rice production and have traditionally been identified only from rice plants and insect vectors by isolation techniques.Advances in next-generation sequencing(NGS)have made it feasible to discover viruses on a global scale.Recently,numerous viruses have been identified in plants and invertebrates using NGS technologies.In this review,we discuss viral studies in rice plants,invertebrate species,and weeds in rice fields.Many novel viruses have been discovered in rice ecosystems through NGS technologies,with some also detected using metatranscriptomic and small RNA sequencing.These analyses greatly expand our understanding of viruses in rice fields and provide valuable insights for developing efficient strategies to manage insect pests and virus-mediated rice diseases.

Mitigating ethyl carbamate production in Chinese rice wine:Role of raspberry extract

This study investigated the use of raspberry extract(RBE) for mitigating ethyl carbamate(EC) accumulation in Chinese rice wine(Huangjiu), a traditional fermented beverage. It focused on the addition of RBE to the fermentation mash and its effects on EC levels. The results showed a significant reduction in EC production that could be attributed to RBE's role in altering urea and citrulline catabolism and inhibiting arginine metabolism, thus preventing EC precursors from reacting with ethanol. Additionally, RBE enhanced the rice wine's flavor profile, as shown by volatile component and amino acid analysis. This study also explored RBE's impact on the metabolism of arginine by Saccharomyces cerevisiae in a simulated fermentation environment, and found increased arginine, reduced urea and citrulline levels, altered enzyme activities, and gene expression changes in the arginine metabolism and transport pathways. In conclusion, the results clearly demonstrated RBE's efficacy in reducing the EC content in Chinese rice wine, offering valuable insights for EC reduction strategies.

Effects of increased seeding density on seedling characteristics,mechanical transplantation quality,and yields of rice with crop straw boards for seedling cultivation

The high labor demand during rice seedling cultivation and transplantation poses a significant challenge in advancing machine-transplanted rice cultivation.This problem may be solved by increasing the seeding rate during seedling production while reducing the number of seedling trays.This study conducted field experiments from 2021 to 2022,using transplanting seedling ages of 10 and 15 days to explore the effects of 250,300,and 350 g/tray on the seedling quality,mechanical transplantation quality,yields,and economic benefits of rice.The commonly used combination of 150 g/tray with a 20-day seedling age in rice production was used as CK.The cultivation of seedlings under a high seeding rate and short seedling age significantly affected seedling characteristics,but there was no significant difference in seedling vitality compared to CK.The minimum number of rice trays used in the experiment was observed in the treatment of 350-10(300 g/tray and 10-day seedling age),only 152-155 trays ha^(-1),resulting in a 62%reduction in the number of trays needed.By increasing the seeding rate of rice,missed holes during mechanical transplantation decreased by 2.8 to 4%.The treatment of 300-15(300 g/tray and 15-day seedling age)achieved the highest yields and economic gains.These results indicated that using crop straw boards can reduce the application of seedling trays.On that basis,rice yields can be increased by raising the seeding rate and shortening the seedling age of rice without compromising seedling quality.

Biofilmed-PGPR:Next-Generation Bioinoculant for Plant Growth Promotion in Rice under Changing Climate

The exopolysaccharide matrix of diazotrophic cyanobacteria was used to integrate phosphorus(P)and potassium(K)solubilizing bacteria,enhancing the survival of plant growth-promoting rhizobacteria,and ultimately the survival of bacteria in the rhizosphere for better plant growth.A new biofilm-based formulation comprising the diazotrophic cyanobacteria Anabaena AMP2,P-solubilizing Bacillus megaterium var.phosphaticum PB1,and K-solubilizing Rhizobium pusense KRBKKM1 was tested for efficacy in rice.The growth medium with half-strength BG-11 medium supplemented with 3%glucose showed best for biofilm formation under in vitro conditions.Analysis of the methanolic extract of the cyanobacterial-bacterial biofilm(CBB)showed the activity of antioxidants,such as 2-methoxy phenol and pentadecane,which are proven to improve plant-microbe interactions and plant growth,respectively.Treatment of rice seeds with CBB extract at 100 mL/kg or 200 mL/kg showed significant enhancement in germination rate and seedling length.Therefore,a pot culture experiment with the CBB formulations was carried out,and different growth and yield parameters were recorded.Principal component analysis showed that plant growth,yield,soil dehydrogenase activity,and soil chlorophyll content were positively correlated with rice plants amended with vermiculite-based CBB at 2 kg/hm^(2) followed by a spray with aqueous CBB formulation at 5 mL/L at 15 and 30 d after rice transplanting grown with a 25%reduced level of nitrogen/phosphorus/potassium chemical fertilizers than the recommended dose.Further,Pearson correlation analysis showed that yield was positively correlated with soil dehydrogenase(r=0.92**)and soil chlorophyll content(r=0.96**).We concluded that CBB could be used as a novel biofilm-based bio-inoculant to increase rice productivity and crop fitness as a component in integrated nutrient management and sustainable organic farming strategies with reduced chemical fertilizers.

Geographical Indications and Regional Public Brands of the Whole Rice Industry Chain in the Yangtze River Economic Belt

The Yangtze River Economic Belt is the main rice producing area in China.The rice industry chain is the agricultural pillar industry chain of this economic belt and it is the key to ensuring national food security and promoting comprehensive rural revitalization.This study discusses the entire rice industry chain in the Yangtze River Economic Belt from the national rice production functional zones,agricultural product quality and safety,national famous and excellent new agricultural products,national specialty agricultural products,"China s good grain and oil"products,and national advantageous characteristic industrial clusters.Then,it discusses the geographical indications of rice and its products in this economic belt from geographical indication products,geographical indication trademarks,agricultural geographical indications,geographical indication standards,geographical indication special indications,national geographical indication product protection demonstration zones,and Chinese geographical indication products protected by the European Union.In addition,it analyzes the five main problems between geographical indications and public brands,such as the limited use of geographical indication specific signs and the imperfect intellectual property protection system for geographical indications.Finally,it proposes eight strategies,including promoting the high-quality development of the entire rice industry chain,creating a geographical indication regional public brand for rice and its products,and implementing geographical indication protection projects.

RICE原则联合手法淋巴引流技术治疗急性期踝关节扭伤的临床效果

踝关节扭伤的急性期,在RICE原则下,结合应用优势较高、疗效突出的手法淋巴结引流技术,探究其应用效果和干预积极性。方法 纳入2020.01-2024.01期间治疗的80例踝关节扭伤患者,均属于急性期,按照随机数字表法,将其分为对比组、试验组,各40例,分别采取常规(RICE原则)、常规+手法淋巴引流技术,对比差异。结果 试验组的疗效更低(P<0.05);干预后,试验组的疼痛、肿胀和踝关节功能评分均更好(P<0.05),其肢体周径、细胞外液含量指标均更好(P<0.05)。结论 联合干预模式(RICE+手法淋巴引流技术)可以有效减少踝关节损伤程度,也可有效减少肿胀程度,减少肢体周径,减少细胞外液浓度,可以有效减少疼痛感,缩短病程,加快疾病康复速度,其干预优势明显。

YOLO-Rice:一种基于YOLOv5的水稻虫害检测

为了保证水稻的高产和稳产、提高水稻虫害检测的识别率,提出一种高效快速的检测算法——YOLO-Rice。首先,在传统YOLOv5s模型的基础上融合CA机制;其次,更换PANet为BiFPN结构;随后,使用更加轻量的CARAFE结构来代替原始的上采样模块;最后,替换损失函数来提高收敛速度,以便更好地进行定位。结果表明,与Faster R-CNN、SSD、YOLOv3等模型相比,YOLO-Rice的检测精确率提高了2.4%~40.8%,召回率提高了6.9%~31.4%,平均精度均值提高了7%~37.2%。由此可说明,改进后的模型在多个方面都优于原模型,具有更强的鲁棒性和更高的准确率,实现了对水稻虫害的准确、高效识别。

The underlying mechanism of variety–water–nitrogen–stubble damage interactions on yield formation in ratoon rice with low stubble height under mechanized harvesting

Agronomic measures are the key to promote the sustainable development of ratoon rice by reducing the damage from mechanical crushing to the residual stubble of the main crop, thereby mitigating the impact on axillary bud sprouting and yield formation in ratoon rice. This study used widely recommended conventional rice Jiafuzhan and hybrid rice Yongyou 2640 as the test materials to conduct a four-factor block design field experiment in a greenhouse of the experimental farm of Fujian Agricultural and Forestry University, China from 2018 to 2019.The treatments included fertilization and no fertilization, alternate wetting and drying irrigation and continuous water flooding irrigation, and plots with and without artificial crushing damage on the rice stubble. At the same time, a 13C stable isotope in-situ detection technology was used to fertilize the pot experiment. The results showed significant interactions among varieties, water management, nitrogen application and stubble status.Relative to the long-term water flooding treatment, the treatment with sequential application of nitrogen fertilizer coupled with moderate field drought for root-vigor and tiller promotion before and after harvesting of the main crop, significantly improved the effective tillers from low position nodes. This in turn increased the effective panicles per plant and grains per panicle by reducing the influence of artificial crushing damage on rice stubble and achieving a high yield of the regenerated rice. Furthermore, the partitioning of 13C assimilates to the residual stubble and its axillary buds were significantly improved at the mature stage of the main crop, while the translocation rate to roots and rhizosphere soil was reduced at the later growth stage of ratooning season rice. This was triggered by the metabolism of hormones and polyamines at the stem base regulated by the interaction of water and fertilizer at this time. We therefore suggest that to achieve a high yield of ratoon rice with low stubble height under mechanized harvesting, the timely application of nitrogen fertilizer is fundamental,coupled with moderate field drying for root-vigor preservation and tiller promotion before and after the mechanical harvesting of the main crop.

A phenology-based vegetation index for improving ratoon rice mapping using harmonized Landsat and Sentinel-2 data

Ratoon rice,which refers to a second harvest of rice obtained from the regenerated tillers originating from the stubble of the first harvested crop,plays an important role in both food security and agroecology while requiring minimal agricultural inputs.However,accurately identifying ratoon rice crops is challenging due to the similarity of its spectral features with other rice cropping systems(e.g.,double rice).Moreover,images with a high spatiotemporal resolution are essential since ratoon rice is generally cultivated in fragmented croplands within regions that frequently exhibit cloudy and rainy weather.In this study,taking Qichun County in Hubei Province,China as an example,we developed a new phenology-based ratoon rice vegetation index(PRVI)for the purpose of ratoon rice mapping at a 30 m spatial resolution using a robust time series generated from Harmonized Landsat and Sentinel-2(HLS)images.The PRVI that incorporated the red,near-infrared,and shortwave infrared 1 bands was developed based on the analysis of spectro-phenological separability and feature selection.Based on actual field samples,the performance of the PRVI for ratoon rice mapping was carefully evaluated by comparing it to several vegetation indices,including normalized difference vegetation index(NDVI),enhanced vegetation index(EVI)and land surface water index(LSWI).The results suggested that the PRVI could sufficiently capture the specific characteristics of ratoon rice,leading to a favorable separability between ratoon rice and other land cover types.Furthermore,the PRVI showed the best performance for identifying ratoon rice in the phenological phases characterized by grain filling and harvesting to tillering of the ratoon crop(GHS-TS2),indicating that only several images are required to obtain an accurate ratoon rice map.Finally,the PRVI performed better than NDVI,EVI,LSWI and their combination at the GHS-TS2 stages,with producer's accuracy and user's accuracy of 92.22 and 89.30%,respectively.These results demonstrate that the proposed PRVI based on HLS data can effectively identify ratoon rice in fragmented croplands at crucial phenological stages,which is promising for identifying the earliest timing of ratoon rice planting and can provide a fundamental dataset for crop management activities.

Regulation of 2-acetyl-1-pyrroline and grain quality in early-season indica fragrant rice by nitrogen and silicon fertilization under different plantation methods

Fragrant rice has a high market value,and it is a popular rice type among consumers owing to its pleasant flavor.Plantation methods,nitrogen(N)fertilizers,and silicon(Si)fertilizers can affect the grain yield and fragrance of fragrant rice.However,the core commercial rice production attributes,namely the head rice yield(HRY)and 2-acetyl-1-pyrroline(2-AP)content of fragrant rice,under various nitrogen and silicon(N-Si)fertilization levels and different plantation methods remain unknown.The field experiment in this study was performed in the early seasons of 2018 and 2019 with two popular indica fragrant rice cultivars(Yuxiangyouzhan and Xiangyaxiangzhan).They were grown under six N-Si fertilization treatments(combinations of two levels of Si fertilizer,0 kg Si ha^(−1)(Si0)and 150 kg Si ha^(−1)(Si1),and three levels of N fertilizer,0 kg N ha^(−1)(N0),150 kg N ha^(−1)(N1),and 220 kg N ha^(−1)(N2))and three plantation methods(artificial transplanting(AT),mechanical transplanting(MT),and mechanical direct-seeding(MD)).The results showed that the N-Si fertilization treatments and all the plantation methods significantly affected the HRY and 2-AP content and related parameters of the two different fragrant rice cultivars.Compared with the Si0N0 treatment,the N-Si fertilization treatments resulted in higher HRY and 2-AP contents.The rates of brown rice,milled rice,head rice,and chalky rice of the fragrant rice also improved with the N-Si fertilization treatments.The N-Si fertilization treatments increased the activities of N metabolism enzymes and the accumulation of N and Si in various parts of the fragrant rice,and affected their antioxidant response parameters.The key parameters for the HRY and 2-AP content were assessed by redundancy analysis.Furthermore,the structural equation model revealed that the Si and N accumulation levels indirectly affected the HRY by affecting the N metabolism enzyme activity,N use efficiency,and grain quality of fragrant rice.Moreover,high N and Si accumulation directly promoted the 2-AP content or affected the antioxidant response parameters and indirectly regulated 2-AP synthesis.The interactions of the MT method with the N-Si fertilization treatments varied in the fragrant rice cultivars in terms of the HRY and 2-AP content,whereas the MD method was beneficial to the 2-AP content in both fragrant rice cultivars under the N-Si fertilization treatments.

Preparation of lactic acid bacteria compound starter cultures based on pasting properties and its improvement of glutinous rice flour and dough

The effects of 5 lactic acid bacteria(LAB)fermentation on the pasting properties of glutinous rice flour were compared,and suitable fermentation strains were selected based on the changes of viscosity,setback value,and breakdown value to prepare LAB compound starter cultures.The results revealed that Latilactobacillus sakei HSD004 and Lacticaseibacillus rhamnosus HSD005 had apparent advantages in increasing the viscosity and reducing the setback and breakdown values of glutinous rice flour.In particular,the compound starter created using the two abovementioned LAB in the ratio of 3:1 had better performance than that using a single LAB in improving the pasting properties and increasing the water and oil absorption capacity of glutinous rice flour.Moreover,the gelatinization enthalpy of the fermented samples increased significantly.For frozen glutinous rice dough stored for 28 days,the viscoelasticity of frozen dough prepared by compound starter was better than that of control dough,and the freezable water content was lower than that of control dough.These results indicate that compound LAB fermentation is a promising technology in the glutinous rice-based food processing industry,which has significance for its application.

Grain Yield,Biomass Accumulation,and Leaf Photosynthetic Characteristics of Rice under Combined Salinity-Drought Stress

Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands,primarily due to insufficient water resources and inadequate irrigation facilities.Consequently,combined salinity-drought stress poses a major threat to rice production.In this study,two salinity levels(NS,non-salinity;HS,high salinity)along with three drought treatments(CC,control condition;DJ,drought stress imposed at jointing;DH,drought stress imposed at heading)were performed to investigate their combined influences on leaf photosynthetic characteristics,biomass accumulation,and rice yield formation.Salinity,drought,and their combination led to a shortened growth period from heading to maturity,resulting in a reduced overall growth duration.Grain yield was reduced under both salinity and drought stress,with a more substantial reduction under the combined salinity-drought stress.The combined stress imposed at heading caused greater yield losses in rice compared with the stress imposed at jointing.Additionally,the combined salinity-drought stress induced greater decreases in shoot biomass accumulation from heading to maturity,as well as in shoot biomass and nonstructural carbohydrate(NSC)content in the stem at heading and maturity.However,it increased the harvest index and NSC remobilization reserve.Salinity and drought reduced the leaf area index and SPAD value of flag leaves and weakened the leaf photosynthetic characteristics as indicated by lower photosynthetic rates,transpiration rates,and stomatal conductance.These reductions were more pronounced under the combined stress.Salinity,drought,and especially their combination,decreased the activities of ascorbate peroxidase,catalase,and superoxide dismutase,while increasing the contents of malondialdehyde,hydrogen peroxide,and superoxide radical.Our results indicated a more significant yield loss in rice when subjected to combined salinity-drought stress.The individual and combined stresses of salinity and drought diminished antioxidant enzyme activities,inhibited leaf photosynthetic functions,accelerated leaf senescence,and subsequently lowered assimilate accumulation and grain yield.

Dynamic changes of rumen microbiota and serum metabolome revealed increases in meat quality and growth performances of sheep fed bio‑fermented rice straw

Background Providing high-quality roughage is crucial for improvement of ruminant production because it is an essential component of their feed.Our previous study showed that feeding bio-fermented rice straw(BF)improved the feed intake and weight gain of sheep.However,it remains unclear why feeding BF to sheep increased their feed intake and weight gain.Therefore,the purposes of this research were to investigate how the rumen micro-biota and serum metabolome are dynamically changing after feeding BF,as well as how their changes influence the feed intake,digestibility,nutrient transport,meat quality and growth performances of sheep.Twelve growing Hu sheep were allocated into 3 groups:alfalfa hay fed group(AH:positive control),rice straw fed group(RS:negative control)and BF fed group(BF:treatment).Samples of rumen content,blood,rumen epithelium,muscle,feed offered and refusals were collected for the subsequent analysis.Results Feeding BF changed the microbial community and rumen fermentation,particularly increasing(P<0.05)relative abundance of Prevotella and propionate production,and decreasing(P<0.05)enteric methane yield.The histomorphology(height,width,area and thickness)of rumen papillae and gene expression for carbohydrate trans-port(MCT1),tight junction(claudin-1,claudin-4),and cell proliferation(CDK4,Cyclin A2,Cyclin E1)were improved(P<0.05)in sheep fed BF.Additionally,serum metabolome was also dynamically changed,which led to up-regulating(P<0.05)the primary bile acid biosynthesis and biosynthesis of unsaturated fatty acid in sheep fed BF.As a result,the higher(P<0.05)feed intake,digestibility,growth rate,feed efficiency,meat quality and mono-unsaturated fatty acid concentration in muscle,and the lower(P<0.05)feed cost per kg of live weight were achieved by feeding BF.Conclusions Feeding BF improved the growth performances and meat quality of sheep and reduced their feed cost.Therefore,bio-fermentation of rice straw could be an innovative way for improving ruminant production with mini-mizing production costs.

Molecular Mechanism of Rice Necrotic Lesion for Optimized Yield and Disease Resistance

How to balance rice resistance and yield is an important issue in rice breeding.Plants with mutated necrotic lesion genes often have persistent broad-spectrum resistance,but this broad-spectrum resistance usually comes at the expense of yield.Currently,many necrotic lesion mutants in rice have been identified,and these genes are involved in disease resistance pathways.This review provides a detailed introduction to the characteristics,classification,and molecular mechanisms of necrotic lesion formation.Additionally,we review the molecular regulatory pathways of genes involved in rice disease resistance.Concurrently,we summarize the relationship between resistance and yield in rice using newly developed gene editing methods.We discuss a rational and precise breeding strategy to better utilize molecular design technology for breeding disease-resistant and high-yield rice varieties.