[Objective] studying the influences of different UV-B radiation treatments in short time on some physiological characteristics of winter wheat seedlings was to provide reference for the mechanism of plant response to ...[Objective] studying the influences of different UV-B radiation treatments in short time on some physiological characteristics of winter wheat seedlings was to provide reference for the mechanism of plant response to ultraviolet irradiation in short time. [Method] The winter wheat taken as materials were treated with 15 and 30 pW/cm^2 UV-B radiation, then the physiological indexes such as pigment content and photosynthetic rate were determined. [ Results] The UV-B treatment caused the declines of chlorophyll content, soluble protein content and water content of leaves, besides, dose-effect was existed. The decline of 30 pW/cm^2 treatment was bigger than that of 15 μW/cm^2 treatment. The influences of UV-B radiation on carotenoid content and anthocyanidin content were similar; the change trends were declined firstly then increased. The UVB treatment with two doses restrained the electron transport of PSⅡ, particularly; the inhibitory effect was biggest after treated 2 h, and then this effect was declined in 4, 6 and 8 h, so the dose-effect was existed. The UV-B radiation with two doses restricted photosynthetic rate and the inhibitory effect increased with the increase of treatment time. The high dose treatment caused huge damage to membrane system, while the result of low dose treatment was not obvious. [ Conclusion] UV-B radiation treatment had dose-effect on winter wheat seedlings in short time and the influence of high dose was bigger than that of low dose. With the increase of treatment time, the damage was alleviated; besides, the result was not similar to that of UV-B radiation in long time.展开更多
After treated with low concentration of La^3 + , the rate of producing active oxygen free radical, the relative permeability of cell membrane, the contents of bivalent iron ion in wheat seedling leaves under water st...After treated with low concentration of La^3 + , the rate of producing active oxygen free radical, the relative permeability of cell membrane, the contents of bivalent iron ion in wheat seedling leaves under water stress were determined. The results show that in wheat seedling leaves, feasible concentrations of La^3 + decreases the accumulation of active oxygen free radical, inhibits the increase of the relative permeability of cell membrane, reduces the content of peroxidation product MDA of membrane lipid, and prevents the plant cell producing more bivalent iron ion which can catalyzed the reaction of Haber-weiss and Fenton to produce more superoxide anion. In addition, purified plasma membrane was isolated by aqueous two-phase partitioning from wheat seedling leaves. The reduction rate of Fe(CN)6^3- by purified plasma membrane in La^3+ -treated wheat seedling leaves is different from those in the absence of La^3+ under water stress. The changing trend of the redox activity to La^3+ is similar to that of the content of Fe^2+ . The results reveal that extraneous La^3+ can alleviate the damages of cell membrane caused by water stress via promoting the activity of redox system and the ability of eliminating ROS in wheat seedling leaves.展开更多
Seedlings of wheat were used as receptor plants to study the allelopathic effects of Adzuki Bean aqueous extracts from different organs and rhizosphere soil at different concentrations (0, 10, 40 and 160 g/L) using ...Seedlings of wheat were used as receptor plants to study the allelopathic effects of Adzuki Bean aqueous extracts from different organs and rhizosphere soil at different concentrations (0, 10, 40 and 160 g/L) using sand culture of pot method. The results indicated that root aqueous extract of adzuki bean presented promotion effects at low concentrations and inhibition effects at the high concentra- tion on the growth of height and young leaf length of wheat seedlings, but inhibition effects at low concentrations and promotion effects at the high concentration on the growth of root length, the number of lateral roots and dry weigh of underground part of wheat seedlings. With the concentrations of rhizosphere soil, root, stem and leaf aqueous extracts of adzuki bean increasing, their inhibitory allelopathic effects on the growth of height and young leaf of wheat seedlings increased; the physiological parameters of wheat seedlings studied at the low concentrations of aqueous extracts, indicated that root and rhizosphere soil aqueous extracts of adzuki bean improved the activities of hyperoxid dismutase (SOD) and peroxide enzyme(POD), but reduced the contents of chlorophyll and malonaldehyde (MDA); the physiological parameters of wheat seedlings studied at the high concentration of aqueous extracts indicated that the leaf aqueous extract of adzuki bean inhibited root vigor, and reduced the contents of Chlorophyll and MDA, but it was found that the aqueous extract significantly improved the activities of SOD and POD; and as to the synthetic allelopathic effect (SE), the allelopathic effects of different tissues and rhizosphere soil of adzuki bean on wheat seedlings were in order of leaf〉stem〉soil〉root.展开更多
Drought is the main abiotic stress that restricts wheat production.The rapid development of sequencing technology and its widespread application to various fields have revealed the structural characteristics and regul...Drought is the main abiotic stress that restricts wheat production.The rapid development of sequencing technology and its widespread application to various fields have revealed the structural characteristics and regulation of related genes through gene expression analysis.Here,we studied responses of wheat plants under drought and rewatering conditions,using morphological and physiological indicators.Moreover,a transcriptome analysis was conducted on Jingmai 12,a drought-resistant wheat strain,to explore the mechanism underlying the response of drought-resistant wheat seedlings to drought stress at the transcriptome level.Drought stress caused morphological and physiological changes in both drought-resistant and-sensitive varieties,but to a greater extent in the drought-sensitive specimen.After re-watering,the drought-resistant wheat showed greater ability to recover than the drought-sensitive wheat.Transcriptome sequencing of Jingmai 12 revealed 97,422 genes,including 80,373 known genes and 17,049 newly predicted genes.The observed upregulation of genes was mostly involved in hormone and signal transduction,carbon metabolism,amino acid synthesis,small molecule production,transmembrane transport,ROS detoxification and defense,drought response protein,and protective enzyme activity.Downregulated genes were mostly involved in photosynthesis,lipid metabolism,signaling,and auxin response.Upon rehydration,these genes and metabolic pathways returned to normal.Our results suggest that all these changes are adaptations to drought stress.Through morphological adaptation,physiological regulation,and the expression of drought-induced genes,normal growth of drought-resistant varieties under drought stress can be promoted.These results increase our understanding of the transcriptomic changes taking place in drought-resistant wheat seedlings under drought stress,and provide a direction for future investigations.展开更多
Wheat seedling line detection is critical for precision agriculture and automatic guidance in early wheat field operation. Aiming at the complex wheat field environment, a method of detecting wheat seedling lines base...Wheat seedling line detection is critical for precision agriculture and automatic guidance in early wheat field operation. Aiming at the complex wheat field environment, a method of detecting wheat seedling lines based on deep learning was proposed in this study. Firstly, a rotated bounding box was created to improve the YOLOv3 model to predict the approximate position of the wheat seedling line;Then, according to the rotated bounding region obtained by the model, the wheat seedling line was detected by fitting the extracted center points. Finally, a comprehensive evaluation method combining angle error and distance error was proposed to evaluate the accuracy of the extracted crop line. By testing images of wheat seedlings in different environments, the results showed that the mean angle error and distance error respectively reached 0.75° and 10.84 pixels while the mean running time was 63.83 ms for a 1920×1080 pixels image. And compared to the original model the improved algorithm model improved the mAP value by 13.2%. The angle error and the distance error of the improved algorithm model were reduced by 51.4% and 39.7%, respectively. The method proposed in this study can accurately detect the wheat seedling lines at different stages and it is also suitable for the environments with weeds, shadow, bright light, and dark light. At the same time, it has a certain adaptability to wheat seedling images with a yaw angle in the shooting process. The research results could provide a reference for the automatic guidance of early wheat field machinery.展开更多
A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd) (0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and ...A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd) (0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing- 9428, Duokang- 1, Jingdong- 11, Jing-411, Jingdong-8 and Zhongrnai-8. The endpoints of wheat seedlings, including seed germination, biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p 〈 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongrnai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongrnai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.展开更多
The effects of exogenous spermidine (Spd) on lipid peroxidation, relative plasma membrane permeability, photosystem Ⅱ (PSII) gene expression and PSII photochemical activity in water-stressed wheat seedlings were ...The effects of exogenous spermidine (Spd) on lipid peroxidation, relative plasma membrane permeability, photosystem Ⅱ (PSII) gene expression and PSII photochemical activity in water-stressed wheat seedlings were investigated. The decrease in relative water content (RWC), Chl content, and 2,6-dichlorophenol indophenol (DCIP) photoreduction of PSII, and increases in electrolyte leakage of plasma membranes and malonyldialdehyde (MDA) in water-stressed leaves was alleviated by Spd pretreatment. Furthermore, Western and Northern blot analysis showed that decreases in the PSll major proteins D1, D2 and LHCII and the transcripts of corresponding genes psbA, psbD and cab were also alleviated by Spd pretreatment under water stress. These results suggest that the application of exogenous Spd protects PSII against water stress at both the transcriptional level and the translational level, and allows PSII to retain a higher activity level during water stress. The protective role of Spd in the photosynthetic apparatus also is discussed.展开更多
With the aim to determine whether coronatine (COR) alleviates drought stress on wheat, two winter wheat (Triticum aestivum L.) cultivars, ChangWu134 (drought-tolerant) and Shan253 (drought-sensitive) were stud...With the aim to determine whether coronatine (COR) alleviates drought stress on wheat, two winter wheat (Triticum aestivum L.) cultivars, ChangWu134 (drought-tolerant) and Shan253 (drought-sensitive) were studied under hydroponic conditions. Seedlings at the three-leaf stage were eultured in a Hoagland solution containing COR at 0.1 ~M for 24 h, and then exposed to 20% polyethylene glycol 6000 (PEG- 6000). Under simulated drought (SD), COR increased the dry weight of shoots and roots of the two cultivars significantly; the root/shoot ratio also increased by 30% for Shan253 and 40% for ChangWu134. Both cultivars treated with COR under SD (0.1COR-I-PEG) maintained significantly higher relative water content, photosynthesis, transpiration, intercellular concentration of CO2 and stomatal conductance in leaves than those not treated with PEG. Under drought, COR significantly decreased the relative conductivity and malondialdehyde production, and the loss of 1,1-diphenyl-2-picrylhydrazyl scavenging activity in leaves was significantly alleviated in COR-treated plants. The activity of peroxidase, catalase, glutathione reductase and ascorbate peroxidase were adversely affected by drought. Leaves of plants treated with COR under drought produced less abscisic acid (ABA) than those not treated. Thus, COR might alleviate drought effects on wheat by reducing active oxygen species production, activating antioxidant enzymes and changing the ABA level.展开更多
Temperature extremes represent an important limiting factor to plant growth and productivity. Low concentration of hydrogen sulfide (H2S) has been proven to function in physiological responses to various stresses. T...Temperature extremes represent an important limiting factor to plant growth and productivity. Low concentration of hydrogen sulfide (H2S) has been proven to function in physiological responses to various stresses. The present study evaluated the effect of foliar application of wheat seedlings with a H2S donor, sodium hydrosulfide (NariS), on the response to acute heat stress. The results showed that pretreatment with NariS could promote heat tolerance of wheat seedlings in a dose-depen- dent manner. Again, it was verified that H2S, rather than other sulfur-containing components or sodion derived from NariS solution, should contribute to the positive role in promoting wheat seedlings against heat stress. To further study antioxidant mechanisms of NariS-induced heat tolerance, superoxide dismutase (SOD, EC 1.15.1.1 ), catalase (CAT, EC 1.11.1.6) and ascorbate peroxidase (APX, EC 1.11.1.11 ) activities, and HzS, hydrogen peroxide (H2O2), malonaldehyde (MDA), and soluble sugar contents in wheat seedlings were determined. The results showed that, under heat stress, the activities of SOD, CAT, and APX, H2S, H2O2, MDA, and soluble sugar contents in NaHS-pretreated seedlings and its control all increased. Meanwhile, NaHS-pretreated seedlings showed higher antioxidant enzymes activities and gene expression levels as well as the H2S and soluble sugar levels, and lower H2O2, MDA contents induced by heat stress. While little effect was detected in antioxidant enzymes activities and soluble substances contents in pretreated wheat seedlings compared with its control under normal culture conditions (data not shown). All of our results suggested that exogenous NariS could alleviate oxidative damage and improve heat tolerance by regulating the antioxidant system in wheat seedlings under heat stress.展开更多
The toxic effects of 1-methyl-3-octylimidazolium bromide ([C8mim]Br) on wheat seedlings were evaluated. Wheat seedlings were cultivated in aqueous solution with [C8mim]Br at different concentrations (0, 1, 2, 4, 6,...The toxic effects of 1-methyl-3-octylimidazolium bromide ([C8mim]Br) on wheat seedlings were evaluated. Wheat seedlings were cultivated in aqueous solution with [C8mim]Br at different concentrations (0, 1, 2, 4, 6, 8 mg/L). The contents of photosynthetic pigment and proline, peroxidation of membrane lipid, and activities of antioxidation enzymes (superoxide dismutase, catalase, peroxidase and ascorbate peroxidase) in leaves were measured on day 7 after treatment with [C8mim]Br. The results showed that [C8mim]Br significantly decreased the contents of photosynthetic pigments, activities of antioxidant enzymes in the wheat leaves and in dry weight of seedlings, while increased the proline content and membrane lipid peroxidation. The results suggested that [C8mim]Br can inhibit photosynthesis and lead to oxidative stress to wheat seedlings.展开更多
Nutrient elements such as chlorophyll,nitrogen and water at the seedling stage are important key factors that could influence growth,development and even the final yield of wheat.In this study,the spectral data of can...Nutrient elements such as chlorophyll,nitrogen and water at the seedling stage are important key factors that could influence growth,development and even the final yield of wheat.In this study,the spectral data of canopy and single wheat plant leaves at seedling stage were acquired in field by using ASD non-imaging hyperspectrometer and imaging spectrometer respectively to establish prediction models for monitoring the growth at the seedling stage of wheat.According to the comparative analysis of models results built through partial least square algorithm(PLS),it was found that the models built using spectral data of canopy based on ASD non-imaging hyperspectrometer and imaging spectrometer both had low precision,which was possibly caused by background such as soil;while the model established from single wheat plant leaves based on the imaging spectrometer had a better effect.At last,the PLS model was established for chlorophyll SPAD value of wheat seedling leaves based on imaging spectrometry and its correlation coefficient R reached 0.8836,and the correlation coefficient R of the relevant model for nitrogen content was 0.8520,suggesting that the superiority of location monitoring of growth at seedling stage of wheat based on hyperspectral imaging is significant.展开更多
Toxicity of the different concentration of Cu^2+ to the wheat seeding and its distribution in the plant were studied by solution culture. The results showed that: The correlation between the content of Cu^2+ in med...Toxicity of the different concentration of Cu^2+ to the wheat seeding and its distribution in the plant were studied by solution culture. The results showed that: The correlation between the content of Cu^2+ in medium and the germination and growth of the seedlings is significant (P〈0.01). The effect of Cu^2+ to the germination, plant height, fresh weight, dried weight and the chlorophyll mount of the wheat seedling was stimulated under lower concentration of Cu^2+ and was inhibited under higher concentration. With the increase of the Cu^2+ concentration in the culture solution, the germination and growth of the seedlings was inhibited. The perfect positive correlation between the Cu^2+ content in the plant and that in the culture solution was noted. Most of Cu^2+ was concentrated in the root, and only a small amount was migrated to the aerial part of the wheat seedling. The sensitivity of each index to the Cu^2+ concentration was ranked as follows: the Cu^2+ content in the plant〉chlorophyll-a〉the ratio of chlorophyll-a to chlorophyll-b〉total chlorophyll〉plant height 〉germination〉fresh weight〉root elongation〉 chlorophyll-b 〉dried weight. The Cu^2+ content in the wheat plant was the most sensitive index to the Cu^2+ concentration in the culture solution.展开更多
Nitrogen(N) is one of the macronutrients required for plant growth, and reasonable application of N fertilizers can increase crop yields and improve their quality. However, excessive application of N fertilizers wil...Nitrogen(N) is one of the macronutrients required for plant growth, and reasonable application of N fertilizers can increase crop yields and improve their quality. However, excessive application of N fertilizers will decrease N use efficiency and also lead to increases in N2O emissions from agricultural soils and many other environmental issues. Research on the effects of different N fertilizer management practices on wheat yields and N2O emissions will assist the selection of effective N management measures which enable achieving high wheat yields while reducing N2O emissions. To investigate the effects of different N management practices on wheat yields and soil N2O emissions, we conducted field trials with 5 treatments of no N fertilizer(CK), farmers common N rate(AN), optimal N rate(ON), 20% reduction in optimal rate+dicyandiamide(ON80%+DCD), 20% reduction in optimal rate+nano-carbon(ON80%+NC). The static closed chamber gas chromatography method was used to monitor N2O emissions during the wheat growing season. The results showed that there were obvious seasonal characteristics of N2O emissions under each treatment and N2O emissions were mainly concentrated in the sowing-greening stage, accounting for 54.6–68.2% of the overall emissions. Compared with AN, N2O emissions were decreased by 23.1, 45.4 and 33.7%, respectively, under ON, ON80%+DCD and ON80%+NC, and emission factors were declined by 22.2, 66.7 and 33.3%, respectively. Wheat yield was increased significantly under ON80%+DCD and ON80%+NC by 12.3 and 11.9%, respectively, relative to AN while there was no significant change in yield in the ON treatment. Compared with ON, overall N2O emissions were decreased by 29.1 and 13.9% while wheat yields improved by 18.3 and 17.9% under ON80%+DCD and ON80%+NC, respectively. We therefore recommend that ON80%+DCD and ON80%+NC be referred as effective N management practices increasing yields while mitigating emissions.展开更多
基金Supported by Natural Science Foundation of China(Grant:30771156)Student Technology New Ideas Project of Liaocheng University(Grant:SRT08111SM2)~~
文摘[Objective] studying the influences of different UV-B radiation treatments in short time on some physiological characteristics of winter wheat seedlings was to provide reference for the mechanism of plant response to ultraviolet irradiation in short time. [Method] The winter wheat taken as materials were treated with 15 and 30 pW/cm^2 UV-B radiation, then the physiological indexes such as pigment content and photosynthetic rate were determined. [ Results] The UV-B treatment caused the declines of chlorophyll content, soluble protein content and water content of leaves, besides, dose-effect was existed. The decline of 30 pW/cm^2 treatment was bigger than that of 15 μW/cm^2 treatment. The influences of UV-B radiation on carotenoid content and anthocyanidin content were similar; the change trends were declined firstly then increased. The UVB treatment with two doses restrained the electron transport of PSⅡ, particularly; the inhibitory effect was biggest after treated 2 h, and then this effect was declined in 4, 6 and 8 h, so the dose-effect was existed. The UV-B radiation with two doses restricted photosynthetic rate and the inhibitory effect increased with the increase of treatment time. The high dose treatment caused huge damage to membrane system, while the result of low dose treatment was not obvious. [ Conclusion] UV-B radiation treatment had dose-effect on winter wheat seedlings in short time and the influence of high dose was bigger than that of low dose. With the increase of treatment time, the damage was alleviated; besides, the result was not similar to that of UV-B radiation in long time.
基金Project supported bythe National Natural Science Foundation of China (30270744) and 863 Program(2002AA241121)
文摘After treated with low concentration of La^3 + , the rate of producing active oxygen free radical, the relative permeability of cell membrane, the contents of bivalent iron ion in wheat seedling leaves under water stress were determined. The results show that in wheat seedling leaves, feasible concentrations of La^3 + decreases the accumulation of active oxygen free radical, inhibits the increase of the relative permeability of cell membrane, reduces the content of peroxidation product MDA of membrane lipid, and prevents the plant cell producing more bivalent iron ion which can catalyzed the reaction of Haber-weiss and Fenton to produce more superoxide anion. In addition, purified plasma membrane was isolated by aqueous two-phase partitioning from wheat seedling leaves. The reduction rate of Fe(CN)6^3- by purified plasma membrane in La^3+ -treated wheat seedling leaves is different from those in the absence of La^3+ under water stress. The changing trend of the redox activity to La^3+ is similar to that of the content of Fe^2+ . The results reveal that extraneous La^3+ can alleviate the damages of cell membrane caused by water stress via promoting the activity of redox system and the ability of eliminating ROS in wheat seedling leaves.
基金Supported by Natural Science Foundation of Shanxi Province(2013011030-1)Fund for Science and Technology Development and Application of Shanxi Normal University(YK1502)~~
文摘Seedlings of wheat were used as receptor plants to study the allelopathic effects of Adzuki Bean aqueous extracts from different organs and rhizosphere soil at different concentrations (0, 10, 40 and 160 g/L) using sand culture of pot method. The results indicated that root aqueous extract of adzuki bean presented promotion effects at low concentrations and inhibition effects at the high concentra- tion on the growth of height and young leaf length of wheat seedlings, but inhibition effects at low concentrations and promotion effects at the high concentration on the growth of root length, the number of lateral roots and dry weigh of underground part of wheat seedlings. With the concentrations of rhizosphere soil, root, stem and leaf aqueous extracts of adzuki bean increasing, their inhibitory allelopathic effects on the growth of height and young leaf of wheat seedlings increased; the physiological parameters of wheat seedlings studied at the low concentrations of aqueous extracts, indicated that root and rhizosphere soil aqueous extracts of adzuki bean improved the activities of hyperoxid dismutase (SOD) and peroxide enzyme(POD), but reduced the contents of chlorophyll and malonaldehyde (MDA); the physiological parameters of wheat seedlings studied at the high concentration of aqueous extracts indicated that the leaf aqueous extract of adzuki bean inhibited root vigor, and reduced the contents of Chlorophyll and MDA, but it was found that the aqueous extract significantly improved the activities of SOD and POD; and as to the synthetic allelopathic effect (SE), the allelopathic effects of different tissues and rhizosphere soil of adzuki bean on wheat seedlings were in order of leaf〉stem〉soil〉root.
基金This research was funded by the China Yunnan Province Agriculture Joint Key Project(2018FG001-005)Yunnan Academician Workstation(2019IC006).
文摘Drought is the main abiotic stress that restricts wheat production.The rapid development of sequencing technology and its widespread application to various fields have revealed the structural characteristics and regulation of related genes through gene expression analysis.Here,we studied responses of wheat plants under drought and rewatering conditions,using morphological and physiological indicators.Moreover,a transcriptome analysis was conducted on Jingmai 12,a drought-resistant wheat strain,to explore the mechanism underlying the response of drought-resistant wheat seedlings to drought stress at the transcriptome level.Drought stress caused morphological and physiological changes in both drought-resistant and-sensitive varieties,but to a greater extent in the drought-sensitive specimen.After re-watering,the drought-resistant wheat showed greater ability to recover than the drought-sensitive wheat.Transcriptome sequencing of Jingmai 12 revealed 97,422 genes,including 80,373 known genes and 17,049 newly predicted genes.The observed upregulation of genes was mostly involved in hormone and signal transduction,carbon metabolism,amino acid synthesis,small molecule production,transmembrane transport,ROS detoxification and defense,drought response protein,and protective enzyme activity.Downregulated genes were mostly involved in photosynthesis,lipid metabolism,signaling,and auxin response.Upon rehydration,these genes and metabolic pathways returned to normal.Our results suggest that all these changes are adaptations to drought stress.Through morphological adaptation,physiological regulation,and the expression of drought-induced genes,normal growth of drought-resistant varieties under drought stress can be promoted.These results increase our understanding of the transcriptomic changes taking place in drought-resistant wheat seedlings under drought stress,and provide a direction for future investigations.
基金funded by the Natural Science Foundation of Shandong Province (Grant No. ZR2021MF096)Shandong Agricultural Machinery Equipment Research and Development Innovation Plan (Grant No. 2018YF009).
文摘Wheat seedling line detection is critical for precision agriculture and automatic guidance in early wheat field operation. Aiming at the complex wheat field environment, a method of detecting wheat seedling lines based on deep learning was proposed in this study. Firstly, a rotated bounding box was created to improve the YOLOv3 model to predict the approximate position of the wheat seedling line;Then, according to the rotated bounding region obtained by the model, the wheat seedling line was detected by fitting the extracted center points. Finally, a comprehensive evaluation method combining angle error and distance error was proposed to evaluate the accuracy of the extracted crop line. By testing images of wheat seedlings in different environments, the results showed that the mean angle error and distance error respectively reached 0.75° and 10.84 pixels while the mean running time was 63.83 ms for a 1920×1080 pixels image. And compared to the original model the improved algorithm model improved the mAP value by 13.2%. The angle error and the distance error of the improved algorithm model were reduced by 51.4% and 39.7%, respectively. The method proposed in this study can accurately detect the wheat seedling lines at different stages and it is also suitable for the environments with weeds, shadow, bright light, and dark light. At the same time, it has a certain adaptability to wheat seedling images with a yaw angle in the shooting process. The research results could provide a reference for the automatic guidance of early wheat field machinery.
基金Project supported by the National Natural Science Foundation of China (No.4073740,20621703).
文摘A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd) (0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing- 9428, Duokang- 1, Jingdong- 11, Jing-411, Jingdong-8 and Zhongrnai-8. The endpoints of wheat seedlings, including seed germination, biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p 〈 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongrnai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongrnai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.
基金Supported by the National Natural Science Foundation of China(30571119)the Sichuan Science and Technology Foundation(04ZQ026-036 and 05JY029-017)+1 种基金the Education Ministry Doctoral Foundation of China (20040610015)the Chengdu Science and Technology Foundation (05HJSW117)
文摘The effects of exogenous spermidine (Spd) on lipid peroxidation, relative plasma membrane permeability, photosystem Ⅱ (PSII) gene expression and PSII photochemical activity in water-stressed wheat seedlings were investigated. The decrease in relative water content (RWC), Chl content, and 2,6-dichlorophenol indophenol (DCIP) photoreduction of PSII, and increases in electrolyte leakage of plasma membranes and malonyldialdehyde (MDA) in water-stressed leaves was alleviated by Spd pretreatment. Furthermore, Western and Northern blot analysis showed that decreases in the PSll major proteins D1, D2 and LHCII and the transcripts of corresponding genes psbA, psbD and cab were also alleviated by Spd pretreatment under water stress. These results suggest that the application of exogenous Spd protects PSII against water stress at both the transcriptional level and the translational level, and allows PSII to retain a higher activity level during water stress. The protective role of Spd in the photosynthetic apparatus also is discussed.
基金supported by grants from the National High Technology Research and Development Program of China(2006AA10A213)the Teaching and Research Award Program for Outstanding Young Teachers in Higher Educational Institutions of the Ministry of Education,China
文摘With the aim to determine whether coronatine (COR) alleviates drought stress on wheat, two winter wheat (Triticum aestivum L.) cultivars, ChangWu134 (drought-tolerant) and Shan253 (drought-sensitive) were studied under hydroponic conditions. Seedlings at the three-leaf stage were eultured in a Hoagland solution containing COR at 0.1 ~M for 24 h, and then exposed to 20% polyethylene glycol 6000 (PEG- 6000). Under simulated drought (SD), COR increased the dry weight of shoots and roots of the two cultivars significantly; the root/shoot ratio also increased by 30% for Shan253 and 40% for ChangWu134. Both cultivars treated with COR under SD (0.1COR-I-PEG) maintained significantly higher relative water content, photosynthesis, transpiration, intercellular concentration of CO2 and stomatal conductance in leaves than those not treated with PEG. Under drought, COR significantly decreased the relative conductivity and malondialdehyde production, and the loss of 1,1-diphenyl-2-picrylhydrazyl scavenging activity in leaves was significantly alleviated in COR-treated plants. The activity of peroxidase, catalase, glutathione reductase and ascorbate peroxidase were adversely affected by drought. Leaves of plants treated with COR under drought produced less abscisic acid (ABA) than those not treated. Thus, COR might alleviate drought effects on wheat by reducing active oxygen species production, activating antioxidant enzymes and changing the ABA level.
基金supported by the Special Fund for Agro-scientific Research in the Public Interest of China (201203029)
文摘Temperature extremes represent an important limiting factor to plant growth and productivity. Low concentration of hydrogen sulfide (H2S) has been proven to function in physiological responses to various stresses. The present study evaluated the effect of foliar application of wheat seedlings with a H2S donor, sodium hydrosulfide (NariS), on the response to acute heat stress. The results showed that pretreatment with NariS could promote heat tolerance of wheat seedlings in a dose-depen- dent manner. Again, it was verified that H2S, rather than other sulfur-containing components or sodion derived from NariS solution, should contribute to the positive role in promoting wheat seedlings against heat stress. To further study antioxidant mechanisms of NariS-induced heat tolerance, superoxide dismutase (SOD, EC 1.15.1.1 ), catalase (CAT, EC 1.11.1.6) and ascorbate peroxidase (APX, EC 1.11.1.11 ) activities, and HzS, hydrogen peroxide (H2O2), malonaldehyde (MDA), and soluble sugar contents in wheat seedlings were determined. The results showed that, under heat stress, the activities of SOD, CAT, and APX, H2S, H2O2, MDA, and soluble sugar contents in NaHS-pretreated seedlings and its control all increased. Meanwhile, NaHS-pretreated seedlings showed higher antioxidant enzymes activities and gene expression levels as well as the H2S and soluble sugar levels, and lower H2O2, MDA contents induced by heat stress. While little effect was detected in antioxidant enzymes activities and soluble substances contents in pretreated wheat seedlings compared with its control under normal culture conditions (data not shown). All of our results suggested that exogenous NariS could alleviate oxidative damage and improve heat tolerance by regulating the antioxidant system in wheat seedlings under heat stress.
基金supported by the National Natural Science Foundation of China(No. 20273019,20573034)the Innovation Project for University Prominent Research Talents of Henan,China(No. 2006KYCX021)the Project-sponsored by SRF for ROCS,SEM(No. [2006]331)
文摘The toxic effects of 1-methyl-3-octylimidazolium bromide ([C8mim]Br) on wheat seedlings were evaluated. Wheat seedlings were cultivated in aqueous solution with [C8mim]Br at different concentrations (0, 1, 2, 4, 6, 8 mg/L). The contents of photosynthetic pigment and proline, peroxidation of membrane lipid, and activities of antioxidation enzymes (superoxide dismutase, catalase, peroxidase and ascorbate peroxidase) in leaves were measured on day 7 after treatment with [C8mim]Br. The results showed that [C8mim]Br significantly decreased the contents of photosynthetic pigments, activities of antioxidant enzymes in the wheat leaves and in dry weight of seedlings, while increased the proline content and membrane lipid peroxidation. The results suggested that [C8mim]Br can inhibit photosynthesis and lead to oxidative stress to wheat seedlings.
基金Natural Science Foundation of China(41371349,31501217)Special Fund for Agro-scientific Research in the Public Interest of China(201203026)+1 种基金Liaoning Province Science and Technology Plan Projects(2014104017)Scientific Research on the General Project of Education Department of Liaoning Province(L2014265,L2015484).
文摘Nutrient elements such as chlorophyll,nitrogen and water at the seedling stage are important key factors that could influence growth,development and even the final yield of wheat.In this study,the spectral data of canopy and single wheat plant leaves at seedling stage were acquired in field by using ASD non-imaging hyperspectrometer and imaging spectrometer respectively to establish prediction models for monitoring the growth at the seedling stage of wheat.According to the comparative analysis of models results built through partial least square algorithm(PLS),it was found that the models built using spectral data of canopy based on ASD non-imaging hyperspectrometer and imaging spectrometer both had low precision,which was possibly caused by background such as soil;while the model established from single wheat plant leaves based on the imaging spectrometer had a better effect.At last,the PLS model was established for chlorophyll SPAD value of wheat seedling leaves based on imaging spectrometry and its correlation coefficient R reached 0.8836,and the correlation coefficient R of the relevant model for nitrogen content was 0.8520,suggesting that the superiority of location monitoring of growth at seedling stage of wheat based on hyperspectral imaging is significant.
文摘Toxicity of the different concentration of Cu^2+ to the wheat seeding and its distribution in the plant were studied by solution culture. The results showed that: The correlation between the content of Cu^2+ in medium and the germination and growth of the seedlings is significant (P〈0.01). The effect of Cu^2+ to the germination, plant height, fresh weight, dried weight and the chlorophyll mount of the wheat seedling was stimulated under lower concentration of Cu^2+ and was inhibited under higher concentration. With the increase of the Cu^2+ concentration in the culture solution, the germination and growth of the seedlings was inhibited. The perfect positive correlation between the Cu^2+ content in the plant and that in the culture solution was noted. Most of Cu^2+ was concentrated in the root, and only a small amount was migrated to the aerial part of the wheat seedling. The sensitivity of each index to the Cu^2+ concentration was ranked as follows: the Cu^2+ content in the plant〉chlorophyll-a〉the ratio of chlorophyll-a to chlorophyll-b〉total chlorophyll〉plant height 〉germination〉fresh weight〉root elongation〉 chlorophyll-b 〉dried weight. The Cu^2+ content in the wheat plant was the most sensitive index to the Cu^2+ concentration in the culture solution.
基金supported by the National Science and Technology Support Program during 12th Five-Year Plan period(2013BAD11B03)the National Natural Science Foundation of China(41105115)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS)
文摘Nitrogen(N) is one of the macronutrients required for plant growth, and reasonable application of N fertilizers can increase crop yields and improve their quality. However, excessive application of N fertilizers will decrease N use efficiency and also lead to increases in N2O emissions from agricultural soils and many other environmental issues. Research on the effects of different N fertilizer management practices on wheat yields and N2O emissions will assist the selection of effective N management measures which enable achieving high wheat yields while reducing N2O emissions. To investigate the effects of different N management practices on wheat yields and soil N2O emissions, we conducted field trials with 5 treatments of no N fertilizer(CK), farmers common N rate(AN), optimal N rate(ON), 20% reduction in optimal rate+dicyandiamide(ON80%+DCD), 20% reduction in optimal rate+nano-carbon(ON80%+NC). The static closed chamber gas chromatography method was used to monitor N2O emissions during the wheat growing season. The results showed that there were obvious seasonal characteristics of N2O emissions under each treatment and N2O emissions were mainly concentrated in the sowing-greening stage, accounting for 54.6–68.2% of the overall emissions. Compared with AN, N2O emissions were decreased by 23.1, 45.4 and 33.7%, respectively, under ON, ON80%+DCD and ON80%+NC, and emission factors were declined by 22.2, 66.7 and 33.3%, respectively. Wheat yield was increased significantly under ON80%+DCD and ON80%+NC by 12.3 and 11.9%, respectively, relative to AN while there was no significant change in yield in the ON treatment. Compared with ON, overall N2O emissions were decreased by 29.1 and 13.9% while wheat yields improved by 18.3 and 17.9% under ON80%+DCD and ON80%+NC, respectively. We therefore recommend that ON80%+DCD and ON80%+NC be referred as effective N management practices increasing yields while mitigating emissions.