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Genomic insights of leafminer resistance in spinach through GWAS approach and genomic prediction
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作者 Ibtisam Alatawi Haizheng Xiong +6 位作者 Beiquan Mou Kenani Chiwina Waltram Ravelombola Qun Luo Yiting Xiao Yang Tian Ainong Shi 《Horticultural Plant Journal》 2026年第2期356-368,共13页
The Leafminers,representing a diverse group of insects from various genera within the Agromyzidae family,pose a significant threat to spinach(Spinacia oleracea L.)production.This study aimed to identify single nucleot... The Leafminers,representing a diverse group of insects from various genera within the Agromyzidae family,pose a significant threat to spinach(Spinacia oleracea L.)production.This study aimed to identify single nucleotide polymorphism(SNP)markers associated with leafminer resistance through a genome-wide association study(GWAS)and to evaluate the prediction accuracy(PA)for selecting resistant spinach using genomic prediction(GP).Using a dataset of 84301 SNPs obtained from whole-genome resequencing,seven GWAS models,including BLINK,FarmCPU,MLM,and MLMM in GAPIT 3,as well as MLM,GLM,and SMR in TASSEL 5,were employed to perform GWAS on a panel of 286 USDA spinach germplasm accessions.Three SNP markers,namely 1_115279256_C_T,3_157082529_C_T,and 4_168510908_T_G on chromosomes 1,3,and 4,respectively,were identified as associated with leafminer resistance.In the 30 kb flanking regions of these markers,four candidate genes(SOV1g031330,SOV1g031340,SOV4g047270,and SOV4g047280),encoding LOB domain-containing protein,KH domain-containing protein,were discovered.Nodulin-like domain-containing protein,and SAM domain-containing protein,were discovered.The PA for leafminer resistance selection was estimated using ten different SNP sets,including two GWAS-derived marker sets(three and 51 SNPs)and eight random marker sets(ranging from 51 to 10 K SNPs)analyzed by seven GP models.The findings emphasized the superior performance of GWAS-derived SNP sets,reaching a PA of up to 0.79 using the cBLUP model.Notably,this research marks the pioneering application of GP in the context of insect resistance,providing a significant advancement in the understanding and management of leafminer resistance in spinach cultivation. 展开更多
关键词 Spinach germplasm Genome-wide association study Pest resistance Genomic prediction
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Predicting the Yield Loss of Winter Wheat Due to Drought in the Llano Estacado Region of the United States Based on the Cultivar-Specific Sensitivity to Drought
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作者 Prem Woli Gerald R. Smith +1 位作者 Charles R. Long Francis M. Rouquette Jr. 《Agricultural Sciences》 2025年第1期13-30,共18页
In most agricultural areas in the semi-arid region of the southern United States, wheat (Triticum aestivum L.) production is a primary economic activity. This region is drought-prone and projected to have a drier clim... In most agricultural areas in the semi-arid region of the southern United States, wheat (Triticum aestivum L.) production is a primary economic activity. This region is drought-prone and projected to have a drier climate in the future. Predicting the yield loss due to an anticipated drought is crucial for wheat growers. A reliable way for predicting the drought-induced yield loss is to use a plant physiology-based drought index, such as Agricultural Reference Index for Drought (ARID). Since different wheat cultivars exhibit varying levels of sensitivity to water stress, the impact of drought could be different on the cultivars belonging to different drought sensitivity groups. The objective of this study was to develop the cultivar drought sensitivity (CDS) group-specific, ARID-based models for predicting the drought-induced yield loss of winter wheat in the Llano Estacado region in the southern United States by accounting for the phenological phase-specific sensitivity to drought. For the study, the historical (1947-2021) winter wheat grain yield and daily weather data of two locations in the region (Bushland, TX and Clovis, NM) were used. The logical values of the drought sensitivity parameters of the yield models, especially for the moderately-sensitive and highly-sensitive CDS groups, indicated that the yield models reflected the phenomenon of water stress decreasing the winter wheat yields in this region satisfactorily. The reasonable values of the Nash-Sutcliffe Index (0.65 and 0.72), the Willmott Index (0.88 and 0.92), and the percentage error (23 and 22) for the moderately-sensitive and highly-sensitive CDS groups, respectively, indicated that the yield models for these groups performed reasonably well. These models could be useful for predicting the drought-induced yield losses and scheduling irrigation allocation based on the phenological phase-specific drought sensitivity as influenced by cultivar genotype. 展开更多
关键词 ARID CULTIVAR DROUGHT Model Phase Prediction SEMI-ARID Stage Wheat Yield
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Genomic insights into oxalate content in spinach:A genome-wide association study and genomic prediction approach
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作者 Haizheng Xiong Kenani Chiwina +6 位作者 Waltram Ravelombola Yilin Chen Ibtisam Alatawi Qun Luo Theresa Makawa Phiri Beiquan Mou Ainong Shi 《Horticultural Plant Journal》 2025年第3期1140-1151,共12页
Oxalate content in spinach is a key trait of interest due to its relevance to human health.Understanding the genetic basis of it can facilitate the development of spinach varieties with reduced oxalate levels.In pursu... Oxalate content in spinach is a key trait of interest due to its relevance to human health.Understanding the genetic basis of it can facilitate the development of spinach varieties with reduced oxalate levels.In pursuit of understanding the genetic determinants,a diverse panel comprising 288 spinach accessions underwent thorough phenotyping of oxalate content and were subjected to whole-genome resequencing,resulting in a comprehensive dataset encompassing 14386 single-nucleotide polymorphisms(SNPs).Leveraging this dataset,we conducted a genome-wide association study(GWAS)to identify noteworthy SNPs associated with oxalate content.Furthermore,we employed genomic prediction(GP)via cross-prediction,utilizing five GP models,to assess genomic estimated breeding values(GEBVs)for oxalate content.The observed normal distribution and the wide range of oxalate content,exceeding 600.0 mg$100 g^(-1),underscore the complex and quantitative nature of this trait,likely influenced by multiple genes.Additionally,our analysis revealed distinct stratification,delineating the population into four discernible subpopulations.Furthermore,GWAS analysis employing five models in GAPIT 3 and TASSEL 5 unveiled nine significant SNPs(four SNPs on chromosome 1 and five on chromosome 5)associated with oxalate content.These loci exhibited associations with six candidate genes,which might have potential contribution to oxalate content regulation.Remarkably,our GP models exhibited notable predictive abilities,yielding average accuracies of up to 0.51 for GEBV estimation.The integration of GWAS and GP approaches offers a holistic comprehension of the genetic underpinnings of oxalate content in spinach.These findings offered a promising avenue for the development of spinach cultivars and hybrids optimized for oxalate levels,promoting consumer health. 展开更多
关键词 GWAS Spinach breeding OXALATE Genomic prediction
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寄生蜂取食寄主特性及其在害虫生物防治中的作用 被引量:23
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作者 史树森 臧连生 +2 位作者 刘同先 阮长春 孙光芝 《昆虫学报》 CAS CSCD 北大核心 2009年第4期424-433,共10页
许多寄生性天敌昆虫的雌虫不仅寄生寄主,而且还能取食寄主。在卵育型(synovigenic)寄生蜂类群中,取食寄主行为是较为普遍的现象。本文综合近20年相关研究进展,从寄生蜂类群、取食类型、生态学意义及影响因子等方面对寄生蜂的取食寄主行... 许多寄生性天敌昆虫的雌虫不仅寄生寄主,而且还能取食寄主。在卵育型(synovigenic)寄生蜂类群中,取食寄主行为是较为普遍的现象。本文综合近20年相关研究进展,从寄生蜂类群、取食类型、生态学意义及影响因子等方面对寄生蜂的取食寄主行为进行了归纳总结。寄生蜂通过取食不仅可以杀死寄主,直接起到控制害虫种群数量的作用,还能通过取食策略为卵的成熟和再生提供营养来源,对延长雌虫的寿命也有一定的帮助。对取食寄主行为的了解可为筛选优势寄生性天敌种类、评估寄生蜂在害虫生物防治中的作用提供重要信息。 展开更多
关键词 取食寄主行为 寄生 卵育型寄生蜂 天敌 生物防治
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基于中分辨卫星影像的农用航空喷药效果评估(英文) 被引量:6
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作者 张东彦 兰玉彬 +4 位作者 王秀 周新根 陈立平 李斌 马伟 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2016年第6期1971-1977,共7页
遥感技术能被用于大尺度作物化学喷药效果检测,这为精准农业航空施药发展提供了重要的技术支撑。利用M-18B农用飞机在4米的飞行高度喷施化学农药混合剂(杀菌剂和植物生长调节剂),去控制水稻爆发性疾病--叶片纹枯病和促进水稻植株的生长... 遥感技术能被用于大尺度作物化学喷药效果检测,这为精准农业航空施药发展提供了重要的技术支撑。利用M-18B农用飞机在4米的飞行高度喷施化学农药混合剂(杀菌剂和植物生长调节剂),去控制水稻爆发性疾病--叶片纹枯病和促进水稻植株的生长。施药一周后,喷药区的卫星影像被获取并计算植被指数,同时采集了地面化学农药的药液沉积量。分析了药液雾滴沉积量和植被指数的关系,结果显示,单相光谱特征(NDVI)和液滴沉积点密度(DDPD点·cm^(-2))的相关系数是0.315,p-value为0.035;时间变化特征(MSAVI)和液滴沉积体积密度(DDVDμL·cm^(-2))之间的相关系数是0.312,p-value为0.038。另外,水稻生长活力最旺盛的范围都出现在喷洒区域内,植株活力随着药液漂移距离的增加逐步减少。同时,相同的变化趋势也出现在雾滴沉积量与光谱特征的空间变化插值图中。由此得知,从卫星图像中计算的植被指数NDVI和MSAVI,可以用来评估大尺度农田的农用航空药液喷洒效果。 展开更多
关键词 卫星影像 植被指数 航空喷药 雾滴沉积 漂移
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Comparison of Organ Morphology and Yield Composition in Different Rice Cultivars
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作者 严定春 王勋 +1 位作者 L.T.Wilson Y. Yang 《Agricultural Science & Technology》 CAS 2012年第10期2088-2092,2151,共6页
[Objective] The study aimed to compare the difference of organ morphology and yield composition in 10 rice cultivars with 3 sowing date,and to correlate leaf length and plant height with exogenous variables like tempe... [Objective] The study aimed to compare the difference of organ morphology and yield composition in 10 rice cultivars with 3 sowing date,and to correlate leaf length and plant height with exogenous variables like temperature accumulation and sunshine duration.[Method] Detailed data of organ morphology and yield component were obtained and analyzed through repeated field observations and destructive samplings over the growing season,including leaf length,node number,tiller number,plant height and grain yield of 10 rice cultivars(Takanari,IR72,Sankeiso,CH86,IR65564-44-2-2,Nipponbare,Takenari,Banten,WAB450-1-B-P-38-HB,Wuxiangjing 9) with 3 sowing dates(May 11,May 22,and June 19,2002).[Result] Max leaf length for each node increased at the early growth stage and decreased at the later growth stage.The leaf length of CH86 and Banten was the maximum in 4 Indica cultivars and 6 Japonica cultivars,respectively.Node number and plant height decreased with the later sowing date,and that of CH86 was the maximum.The maximum grain yield was found in Wuxiangjing 9,and the greatest genotypic variation existed in rice yield,panicle number,spikelet per panicle,and grain weight;the grain yield ranged from 4 358 to 7 443 kg ha-1;the panicle number ranged from 158×104 to 330×104 ha-1;no direct correlation between yield,tiller number and plant height was observed in this experiment.[Conclusion] Empirical regression fitting of the resulting data was developed for leaf length and plant height prediction and yield component comparison,which could be used to construct deeper and more mechanistic models or to optimize rice growing conditions. 展开更多
关键词 LEAF Plant height YIELD GDD Sunshine duration
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低空遥感平台下可见光与多光谱传感器在水稻纹枯病病害评估中的效果对比研究 被引量:24
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作者 赵晓阳 张建 +3 位作者 张东彦 周新根 刘小辉 谢静 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2019年第4期1192-1198,共7页
高效无损地评估农作物病害等级,对于实际农业生产和研究都具有重要意义。研究探讨了基于低空无人机遥感平台进行水稻纹枯病病害等级评估的可行性,分析可见光与多光谱传感器的光谱响应差异及其对感病水稻光谱反射率获取的影响,并定量对... 高效无损地评估农作物病害等级,对于实际农业生产和研究都具有重要意义。研究探讨了基于低空无人机遥感平台进行水稻纹枯病病害等级评估的可行性,分析可见光与多光谱传感器的光谱响应差异及其对感病水稻光谱反射率获取的影响,并定量对比两种传感器的病害监测效果。实验研究区由67个不同品种的水稻小区组成,每块小区均分为相接的纹枯病接种区和侵染区。以大疆精灵Phantom 3 Advanced小型消费级无人机作为搭载平台,分别搭载该无人机系统自带的可见光传感器和MicasenseRedEdge^(TM)多光谱传感器获取遥感影像。同时,通过植保专家现场调查的方式识别病害等级,并利用Trimble公司的手持式NDVI测量仪获取实测NDVI值。基于影像拼接、波段叠合、辐射校正后的预处理结果,对可见光图像的接种区和侵染区共134个小区计算七种可见光植被指数,即NDI(normalized difference index), ExG(excess green), ExR(excess red), ExG-ExR, B~*, G~*, R~*,多光谱图像除上述可见光指数外再计算NDVI(normalized difference vegetation index), RVI(ratio vegetation index)和NDWI(normalized difference water Index)三种多光谱植被指数。将计算得到的图像植被指数与地面实测NDVI进行相关性分析,以选取两种传感器的最优图像植被指数建立水稻纹枯病病害等级反演模型。相关性分析结果表明,基于多光谱传感器计算的图像NDVI与实测NDVI拟合度最高,接种区R^2为0.914, RMSE为0.024,侵染区R^2为0.863, RMSE为0.024。对于可见光传感器, NDI与实测NDVI的相关性最好,接种区R^2为0.875, RMSE为0.011,侵染区R^2为0.703, RMSE为0.014。比较两种传感器两种区域的同一图像植被指数与实测NDVI的一致性,除B~*外, NDI, ExR, ExG-ExR, G~*, ExG, R~*与实测NDVI基本属于高度相关,在病害严重的接种区,两种传感器对水稻纹枯病的监测效果相近,但在病害相对较轻的侵染区,多光谱传感器的监测更为精确灵敏。基于多光谱图像NDVI建立的病害等级反演模型,R^2达到0.624, RMSE为0.801,预测精度达到90.04%,模型效果良好。而基于可见光图像NDI建立的反演模型,R^2为0.580, RMSE为0.847,预测精度为89.45%,效果稍差。对比分析可见光与多光谱传感器的光谱响应曲线,可见光传感器可获取可见光范围的红、绿、蓝三个波段,波段范围互相重叠,多光谱传感器包含五个成像单元,可独立获取从可见光到近红外的五个窄波光谱波段,提供更加准确的光谱信息。比较传感器获取的接种区和侵染区水稻平均反射率曲线得出,多光谱传感器不仅在可见光波段反映了较可见光传感器更强的差异,在红边和近红外波段差异则更加明显,这说明专业窄波段传感器在病害监测方面较宽波段消费级传感器更有优势。综上所述,基于可见光与多光谱传感器的低空无人机遥感平台进行水稻纹枯病病害等级评估是可行的,多光谱传感器精确灵敏,可用于纹枯病的早期监测,可见光传感器效果稍差但经济易于推广。研究结果为病虫害防治提供决策支持,有助于推动实现精准农业,保障粮食安全。 展开更多
关键词 多光谱传感器 可见光传感器 低空遥感 水稻纹枯病 病害等级评估 植被指数
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Effects of saline irrigation on soil salt accumulation and grain yield in the winter wheat-summer maize double cropping system in the low plain of North China 被引量:16
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作者 LIU Xiu-wei Til Feike +3 位作者 CHEN Su-ying SHAO Li-wei SUN Hong-yong ZHANG Xi-ying 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第12期2886-2898,共13页
In the dominant winter wheat (WW)-summer maize (SM) double cropping system in the low plain located in the North China, limited access to fresh water, especially during dry season, constitutes a major obstacle to ... In the dominant winter wheat (WW)-summer maize (SM) double cropping system in the low plain located in the North China, limited access to fresh water, especially during dry season, constitutes a major obstacle to realize high crop productivity. Using the vast water resources of the saline upper aquifer for irrigation during WW jointing stage, may help to bridge the peak of dry season and relieve the tight water situation in the region. A field experiment was conducted during 2009-2012 to investigate the effects of saline irrigation during WW jointing stage on soil salt accumulation and productivity of WW and SM. The experiment treatments comprised no irrigation (T1), fresh water irrigation (T2), slightly saline water irrigation (T3:2.8 dS m-l), and strongly saline water irrigation (T4:8.2 dS m-1) at WW jointing stage. With regard to WW yields and aggregated annual WW-SM yields, clear benefits of saline water irrigation (T3 & T4) compared to no irrigation (T1), as well as insignificant yield losses compared to fresh water irrigation (T2) occurred in all three experiment years. However, the increased soil salinity in eady SM season in consequence of saline irrigation exerted a negative effect on SM photosynthesis and final yield in two of three experiment years. To avoid the negative aftereffects of saline irrigation, sufficient fresh water irrigation during SM sowing phase (i.e., increase from 60 to 90 mm) is recommended to guarantee good growth conditions during the sensitive early growing period of SM. The risk of long-term accumulation of salts as a result of saline irrigation during the peak of dry season is considered low, due to deep leaching of salts during regularly occurring wet years, as demonstrated in the 2012 experiment year. Thus, applying saline water irrigation at jointing stage of WW and fresh water at sowing of SM is most promising to realize high yield and fresh irrigation water saving. 展开更多
关键词 winter wheat summer maize soil salinity saline water irrigation salt balance
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The effects of soil moisture and salinity as functions of groundwater depth on wheat growth and yield in coastal saline soils 被引量:7
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作者 ZHANG He LI Yan +5 位作者 MENG Ya-li CAO Nan LI Duan-sheng ZHOU Zhi-guo CHEN Bing-lin DOU Fu-gen 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2019年第11期2472-2482,共11页
In the coastal saline soils,moisture and salinity are the functions of groundwater depth affecting crop growth and yield.Accordingly,the objectives of this study were to:1)investigate the combined effects of moisture ... In the coastal saline soils,moisture and salinity are the functions of groundwater depth affecting crop growth and yield.Accordingly,the objectives of this study were to:1)investigate the combined effects of moisture and salinity stresses on wheat growth as affected by groundwater depth,and 2)find the optimal groundwater depth for wheat growth in coastal saline soils.The groundwater depths(0.7,1.1,1.5,1.9,2.3,and 2.7 m during 2013-2014(Y1)and 0.6,1.0,1.4,1.8,2.2,and 2.6 m during 2014-2015(Y2))of the field experiment were maintained by soil columns.There was a positive correlation between soil moisture and salinity.Water logging with high salinity(groundwater depth at 0.7 m in Y1 and 0.6 m in Y2)showed a greater decline towards wheat growth than that of slight drought with medium(2.3 m in Y1)or low salinity(2.7 m in Y1,2.2 and 2.6 m in Y2).The booting stage was the most sensitive stage of wheat crop under moisture and salinity stresses.Data showed the most optimal rate of photosynthesis,grain yield,and flour quality were obtained under the groundwater depth(ditch depth)of 1.9 m(standard soil moisture with medium salinity)and 2.3 m(slight drought with medium salinity)in Y1 and 1.8 m(standard soil moisture with medium salinity)and 2.2 m(slight drought with low salinity)in Y2.The corresponding optimal soil relative moisture content and conductivity with the 1:5 distilled water/soil dilution,in the depth of 0-20 cm and 20-40 cm in coastal saline soils,were equal to 58.67-63.07%and 65.51-72.66%in Y1,63.09-66.70%and 69.75-74.72%in Y2;0.86-1.01 dS m^-1 and 0.63-0.77 dS m^-1 in Y1,0.57-0.93 dS m^-1 and 0.40-0.63 dS m^-1 in Y2,respectively. 展开更多
关键词 COUPLE stress SOIL relative moisture content SOIL CONDUCTIVITY PHOTOSYNTHESIS growth stage
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Soil Enzyme Activities and Organic Matter Composition Affected by 26 Years of Continuous Cropping 被引量:14
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作者 Fugen DOU Alan L.WRIGHT +2 位作者 Rao S.MYLAVARAPU JIANG Xianjun John E.MATOCHA 《Pedosphere》 SCIE CAS CSCD 2016年第5期618-625,共8页
The study was to determine the long-term effects of subtropical monoculture and rotational cropping systems and fertilization on soil enzyme activities and soil C, N, and P levels. Cropping systems included continuous... The study was to determine the long-term effects of subtropical monoculture and rotational cropping systems and fertilization on soil enzyme activities and soil C, N, and P levels. Cropping systems included continuous sorghum(Sorghum bicolor L.), cotton(Gossypium hirsutum L.), corn(Zea mays L.), and cotton/sorghum rotations after 26 years of treatment imposition. Soil under continuous sorghum and continuous corn had 15% and 11%, respectively, greater C concentrations than soil under continuous cotton.Organic C was 10% higher at 0–7.5 cm than at 7.5–15 cm. Total N followed similar trends with soil depth as organic C. Continuous sorghum had 19% higher total N than other crop species and rotations. With fertilization, continuous cotton had the highest total P at 0–7.5 cm and sorghum had the highest at 7.5–15 cm. Soil total P was 14% higher at 0–7.5 than at 7.5–15 cm, and fertilization increased 15% total P compared to unfertilized soil. Arylsulfatase, alkaline phosphatase, and β-d-glucosidase activity were the highest for sorghum and the lowest for cotton. Rotation increased enzyme activities compared to continuous cotton but not for continuous sorghum. Of all crop species and rotations, continuous cotton generally showed the lowest levels of organic matter and enzyme activities after 26 years. Fertilization significantly increased the yields for all cropping systems, but rotation had no significant effect on either sorghum or cotton lint yield compared to each crop grown in monoculture. Long-term cropping did not increase soil organic matter levels beyond short-term gains, indicating the difficulty in promoting C sequestration in subtropical soils. 展开更多
关键词 C sequestration FERTILIZATION MONOCULTURE ROTATION subtropical soil
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Effect of Source-Sink Manipulation on Photosynthetic Characteristics of Flag Leaf and the Remobilization of Dry Mass and Nitrogen in Vegetative Organs of Wheat 被引量:7
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作者 ZHANG Ying-hua SUN Na-na +6 位作者 HONG Jia-pei ZHANG Qi WANG Chao XUE Qing-wu ZHOU Shun-li HUANG Qin WANG Zhi-min 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第8期1680-1690,共11页
The photosynthetic characteristics of flag leaf and the accumulation and remobilization of pre-anthesis dry mass(DM) and nitrogen(N) in vegetable organs in nine wheat cultivars under different source-sink manipula... The photosynthetic characteristics of flag leaf and the accumulation and remobilization of pre-anthesis dry mass(DM) and nitrogen(N) in vegetable organs in nine wheat cultivars under different source-sink manipulation treatments including defoliation(DF), spike shading(SS) and half spikelets removal(SR) were investigated. Results showed that the SS treatment increased the photosynthetic rate(Pn) of flag leaf in source limited cultivar, but had no significant effect on sink limited cultivar. The SR treatment decreased the Pn of flag leaf. Grain DM accumulation was limited by source in some cultivars, in other cultivars, it was limited by sink. Grain N accumulation was mainly limited by source supply. The contribution of pre-anthesis dry mass to grain yield from high to low was stem, leaf and chaff, while the contribution of pre-anthesis N to grain N from high to low was leaf, stem and chaff. Cultivars S7221 and TA9818 can increase the contribution of remobilization of DM and N to grain at the maximum ratio under reducing source treatments, which may be the major reason for these cultivars having lower decrease in grain yield and N content under reducing source treatments. 展开更多
关键词 genotypic variation remobilization of pre-anthesis dry mass and nitrogen source-sink treatment WHEAT
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Co-incorporation of rice straw and leguminous green manure can increase soil available nitrogen(N)and reduce carbon and N losses:An incubation study 被引量:20
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作者 Guopeng ZHOU Weidong CAO +5 位作者 Jinshun BAI Changxu XU Naohua ZENG Songjuan GAO Robert M.REES Fugen DOU 《Pedosphere》 SCIE CAS CSCD 2020年第5期661-670,共10页
Returning rice straw and leguminous green manure alone or in combination to soil is effective in improving soil fertility in South China.Despite the popularity of this practice,our understanding o f the underlying pro... Returning rice straw and leguminous green manure alone or in combination to soil is effective in improving soil fertility in South China.Despite the popularity of this practice,our understanding o f the underlying processes for straw and manure combined application is relatively poor.In this study,rice straw(carbon(C)/nitrogen(N)ratio of 63),green manure(hairy vetch,C/N ratio of 14),and their mixtures(C/N ratio of 25 and 35)were added into a paddy soil,and their effects on soil N availability and C or N loss under waterlogged conditions were evaluated in a 100-d incubation experiment.All plant residue treatments significantly enhanced C〇2 and CH4 emissions,but decreased N2O emission.Dissolved organic C(DOC)and N(DON)and microbial biomass C in soil and water-soluble organic C and N and mineral N in the upper aqueous layer above soil were also enhanced by all the plant residue treatments except the rice straw treatment,and soil microbial biomass N and mineral N were lower in the rice straw treatment than in the other treatments.Changes in plant residue C/N ratio,DOC/DON ratio,and cellulose content significantly affected greenhouse gas emissions and active C and N concentrations in soil.Additionally,the treatment with green manure alone yielded the largest C and N losses,and incorporation of the plant residue mixture with a C/N ratio of 35 caused the largest net global warming potential(nGWP)among the amended treatments.In conclusion,the co-incorporation of rice straw and green manure can alleviate the limitation resulting from only applying rice straw(N immobilization)or the sole application of leguminous green manure(high C and N losses),and the residue mixture with a C/N ratio of 25 is a better option because of lower nGWP. 展开更多
关键词 active C and N pools C/N ratio global warming potential greenhouse gas plant residues straw returning
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Numerical Simulation on a Tremendous Debris Flow Caused by Typhoon Morakot in the Jiaopu Stream,Taiwan 被引量:4
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作者 HSU Yu-chao YEN Haw +1 位作者 TSENG Wen-hsiao JAN Chyan-deng 《Journal of Mountain Science》 SCIE CSCD 2014年第1期1-18,共18页
In August 2009,Typhoon Morakot brought a large amount of rainfall with both high intensity and long duration to a vast area of Taiwan.Unfortunately,this resulted in a catastrophic landslide in Hsiaolin Village,Taiwan.... In August 2009,Typhoon Morakot brought a large amount of rainfall with both high intensity and long duration to a vast area of Taiwan.Unfortunately,this resulted in a catastrophic landslide in Hsiaolin Village,Taiwan.Meanwhile,large amounts of landslides were formed in the Jiaopu Stream watershed near the southeast part of the Hsiaolin Village.The Hsiaolin Village access road(Provincial Highway No.21 and Bridge No.8) was completely destroyed by the landslide and consequent debris flow.The major scope of this study is to apply a debris flow model to simulate the disaster caused by the debris flow that occurred in the Jiaopu Stream during Typhoon Morakot.According to the interviews with local residents,this study applied the destruction time of Bridge No.8 and Chen's house to verify the numerical debris flow model.By the spatial rainfall distributions information,the numerical simulations of the debris flow are conducted in two stages.In the first stage(before the landslide-dam failure),the elevation of the debris flow and the corresponding potential damages toward residential properties were investigated.In the second stage(after the landslidedam failure),comparisons of simulation results between the longitudinal and cross profiles of the Jiaopu Stream were performed using topographic maps and satellite imagery.In summary,applications of the adopted numerical debris flow model have shown positive impact on supporting better understanding of the occurrence and movement of debris flow processes. 展开更多
关键词 TYPHOON Morakot DEBRIS flow Numerical simulation Jiaopu STREAM Hsiaolin VILLAGE
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Effects of nitrogen management on the ratoon crop yield and head rice yield in South USA 被引量:8
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作者 WANG Yue-chao LI Xiu-fen +2 位作者 Lee TARPLEY PENG Shao-bing DOU Fu-gen 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2021年第6期1457-1464,共8页
Ratoon rice cropping is an important component of the rice cropping system in Texas and south Louisiana,USA,and expanded to Asian countries in 1970.Two field studies were conducted with widely planted rice(Oryza sativ... Ratoon rice cropping is an important component of the rice cropping system in Texas and south Louisiana,USA,and expanded to Asian countries in 1970.Two field studies were conducted with widely planted rice(Oryza sativa L.)cultivars at Eagle Lake,Texas,USA to determine the effects of nitrogen(N)management in main(first)crop(MC)and ratoon(second)crop(RC)on RC yield.In 2012 and 2013,one cultivar(Presidio)was adopted to determine the effects of RC N management on ratoon yield and head rice yield.In 2016 and 2017,CL153,CL163 and CL272 in addition to Presidio were adopted to examine the effect of MC N management on ratoon yield and head rice yield.N applied at preflood after MC harvest considerably improved RC yield.Application of 99 kg N ha^(–1)at preflood after MC harvest was practically adequate for RC regrowth,development and approaching the yield potential for Presidio.RC could produce quite high average grain yields of 5.90 to 6.53 t ha–1 in 2012 and 2013,respectively.Main crop N rate only significantly affected MC yield;however,given N applied of 99 kg ha^(–1)at preflood after MC harvest,ratoon yield was not significantly affected by MC N rate.Neither the main nor ratoon crop N management had a significant effect on RC head rice yield.Considerable RC head rice yields(55–65%)were observed in all of the four cultivars and 4 years except for CL272 in 2016.These results indicat that without very high N fertilizer application,rice ratoon crop could produce a considerable grain yield and an expectative head rice yield.Rice ratooning could be a practical way to increase rice yields with the minimal input in south Texas and regions with a similar climate. 展开更多
关键词 rice nitrogen management main crop ratoon crop grain yield head rice yield
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Impact of time lags on diurnal estimates of canopy transpiration and canopy conductance from sap-flow measurements of Populus cathayana in the Qinghai–Tibetan Plateau 被引量:4
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作者 Hui Wang Kangning He +4 位作者 Runjie Li Zhuping Sheng Yun Tian Jun Wen Bo Chang 《Journal of Forestry Research》 SCIE CAS CSCD 2017年第3期481-490,共10页
Recently, canopy transpiration (Ec) has been often estimated by xylem sap-flow measurements. However, there is a significant time lag between sap flow measured at the base of the stem and canopy transpiration due to... Recently, canopy transpiration (Ec) has been often estimated by xylem sap-flow measurements. However, there is a significant time lag between sap flow measured at the base of the stem and canopy transpiration due to the capacitive exchange between the transpiration stream and stem water storage. Significant errors will be introduced in canopy conductance (gc) and canopy transpiration estimation if the time lag is neglected. In this study, a cross-correlation analysis was used to quantify the time lag, and the sap flowbased transpiration was measured to pararneterize Jarvistype models of gc and thus to simulate Ec of Populus cathayana using the Penman-Monteith equation. The results indicate that solar radiation (Rs) and vapor pressure deficit (VPD) are not fully coincident with sap flow and have an obvious lag effect; the sap flow lags behind Rs and precedes VPD, and there is a 1-h time shift between Eo and sap flow in the 30-min interval data set. A parameterized Jarvis-type gc model is suitable to predict P. cathayana transpiration and explains more than 80% of the variation observed in go, and the relative error was less than 25%, which shows a preferable simulation effect. The root mean square error (RMSEs) between the predicted and measured Ec were 1.91×10^-3 (with the time lag) and 3.12×10^-3cm h^-1 (without the time lag). More importantly, Ec simulation precision that incorporates time lag is improved by 6% compared to the results without the time lag, with the mean relative error (MRE) of only 8.32% and the mean absolute error (MAE) of 1.48 × 10^-3 cm h^-1. 展开更多
关键词 Canopy transpiration Model - Populuscathayana Qinghai-Tibetan Plateau Sap flow Time lags
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远红光有效促进罗勒植株的生物量和叶片花青素、总酚及类黄酮的积累 被引量:5
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作者 窦海杰 Genhua Niu +1 位作者 Mengmeng Gu Joseph Masabni 《中国蔬菜》 北大核心 2022年第5期81-88,共8页
为了明确远红光代替部分光合有效辐射对植株生物量和叶片花青素、总酚及类黄酮含量的影响,以绿叶罗勒为研究对象,在人工光型植物工厂内保持总光量子通量密度为230μmol·m^(-2)·s^(-1)、光周期16 h/8 h(昼/夜)的条件下,测定远... 为了明确远红光代替部分光合有效辐射对植株生物量和叶片花青素、总酚及类黄酮含量的影响,以绿叶罗勒为研究对象,在人工光型植物工厂内保持总光量子通量密度为230μmol·m^(-2)·s^(-1)、光周期16 h/8 h(昼/夜)的条件下,测定远红光代替部分光合有效辐射对绿叶罗勒植株光合、形态、生物量和叶片花青素、总酚及类黄酮含量的影响。结果表明,与对照相比,远红光处理的绿叶罗勒植株地上部鲜质量和干质量分别提高了6%~23%和4%~28%,株高和开展度分别提高了49%~65%和10%~17%。远红光处理显著提高了部分光源下的罗勒叶片和整株的花青素、总酚和类黄酮含量,叶片的抗氧化活性显著提高了21%~44%,对植株的净光合速率和叶面积无显著影响。 展开更多
关键词 远红光 罗勒 次生代谢 LED光源 光合作用效率 光合作用系统
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Soil Organic Carbon Pools Under Switchgrass Grown as a Bioenergy Crop Compared to Other Conventional Crops 被引量:2
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作者 F.G.DOU F.M.HONS +3 位作者 W.R.OCUMPAUGH J.C.READ M.A.HUSSEY J.P.MUIR 《Pedosphere》 SCIE CAS CSCD 2013年第4期409-416,共8页
Switchgrass (Panicum virgaturn L.) has been proposed as a sustainable bioenergy crop because of its high yield potential, adap- tation to marginal sites, and tolerance to water and nutrient limitations. A better und... Switchgrass (Panicum virgaturn L.) has been proposed as a sustainable bioenergy crop because of its high yield potential, adap- tation to marginal sites, and tolerance to water and nutrient limitations. A better understanding of the potential effects of biomass energy crop production practices on soil biological properties and organic matter dynamics is critical to its production. Our objective was to evaluate changes in C pools under a warm-season perennial switchgrass in different soils compared to typically-grown crops col- lected at College Station, Dallas, and Stephenville, TX in February 2001. Sampling depths were 0-5, 5-15, and 15-30 cm. Switchgrass increased soil organic C (SOC), soil microbial biomass C (SMBC), mineralizable C, and particulate organic matter C (POM-C) com- pared to conventional cropping systems. Soil C concentrations were in the order: long-term coastal bermudagrass [Cynodon dactylon (L.) Pers.] 〉 switchgrass or kleingrass (Panicum coloratura L.) planted in 1992 〉 switchgrass 1997 〉 conventional cropping systems. Soil C concentrations tended to increase with increasing clay content. Greater microbial biomass C followed the order of Dallas 〉 College Station 〉 Stephenville, and ranged from approximately 180 mg C kg-1 soil at Stephenville to 1 900 mg C kg-1 soil at Dallas. Particulate organic C was more sensitive than other fractions to management, increasing as much as 6-fold under long-term coastal bermudagrass compared to conventional cropping systems. Our study indicated that conversion of conventional cropping systems into switchgrass production can sequestrate more SOC and improve soil biological properties in the southern USA. 展开更多
关键词 cropping systems particulate organic C perennial grasses soil microbial biomass C soil mineralizable C
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Remote Monitoring of Wheat Streak Mosaic Progression Using Sub-Pixel Classification of Landsat 5 TM Imagery for Site Specific Disease Management in Winter Wheat 被引量:4
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作者 Mustafa Mirik R. James Ansley +2 位作者 Jacob A. Price Fekede Workneh Charles M. Rush 《Advances in Remote Sensing》 2013年第1期16-28,共13页
Wheat streak mosaic (WSM), caused by Wheat streak mosaic virus is a viral disease that affects wheat (Triticum aestivum L.), other grains, and numerous grasses over large geographical areas around the world. To improv... Wheat streak mosaic (WSM), caused by Wheat streak mosaic virus is a viral disease that affects wheat (Triticum aestivum L.), other grains, and numerous grasses over large geographical areas around the world. To improve disease management and crop production, it is essential to have adequate methods for monitoring disease epidemics at various scales and multiple times. Remote sensing has become an essential tool for monitoring and quantifying crop stress due to biotic and abiotic factors. The objective of our study was to explore the utility of Landsat 5 TM imagery for detecting, quantifying, and mapping the occurrence of WSM in irrigated commercial wheat fields. The infection and progression of WSM was biweekly assessed in the Texas Panhandle during the 2007-2008 crop years. Diseased-wheat was separated from uninfected wheat on the images using a sub-pixel classifier. The overall classification accuracies were >91% with kappa coefficient between 0.80 and 0.94 for disease detection were achieved. Omission errors varied between 2% and 14%, while commission errors ranged from 1% to 21%. These results indicate that the TM image can be used to accurately detect and quantify disease for site-specific WSM management. Remote detection of WSM using geospatial imagery may substantially improve monitoring, planning, and management practices by overcoming some of the shortcomings of the ground-based surveys such as observer bias and inaccessibility. Remote sensing techniques for accurate disease mapping offer a unique set of advantages including repeatability, large area coverage, and cost-effectiveness over the ground-based methods. Hence, remote detection is particularly and practically critical for repeated disease mo- nitoring and mapping over time and space during the course of a growing season. 展开更多
关键词 WHEAT STREAK MOSAIC Virus Viral DISEASE Remote Sensing of DISEASE DISEASE Mapping WHEAT DISEASE SITE-SPECIFIC DISEASE Management
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Evaluation and Selection of High Biomass Rice (<i>Oryza sativa L.</i>) for Drought Tolerance 被引量:3
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作者 Aditi Kondhia Rodante Escleto Tabien Amir Ibrahim 《American Journal of Plant Sciences》 2015年第12期1962-1972,共11页
Biomass production is important in increasing yield not only for food but also for bio-fuel production that depends on high dry matter. Due to climate change, occurrence of drought may be prevalent and this affects bo... Biomass production is important in increasing yield not only for food but also for bio-fuel production that depends on high dry matter. Due to climate change, occurrence of drought may be prevalent and this affects both grain and biomass yields in crops including rice. The objectives of this study were to determine the performance of selected high biomass breeding rice lines to different levels of drought and use several drought tolerance indices to identify best genotypes that could be grown in unfavorable water stressed areas. A rainfed and flooded trial was conducted to evaluate 20 selected breeding lines for biomass production and ten entries from the same set were grown in the greenhouse at three different field capacities (FC, 50%, 75%, 100%). Most of the genotypes performed well under non-stressed conditions (flooded and 100% FC) but some genotypes performed well in water stressed condition. The plants had lower plant height, tiller plant-1, and total biomass at maturity under rainfed conditions and their flowering was delayed compared to flooded conditions. In the greenhouse, water stress slowed the rate of increase in height, and produced lower shoot and root weight, percent dry matter (% DM) and total biomass. However, drought enhanced the rate of tiller production. Two genotypes were found to more tolerant to drought stress and could be used for cultivation under water stress condition to get optimum biomass yields. These genotypes can be identified using drought tolerance indices, particularly stress tolerance index (STI), geometric mean productivity (GMP), mean productivity (MP) and harmonic mean (HARM), as these have a similar ability to separate drought sensitive and tolerant genotypes. Genetic and molecular analyses, and detailed characterization of these genotypes will help understand their inheritance pattern and the number of genes controlling the traits and determine specific leaves and root traits important in developing high biomass rice. 展开更多
关键词 HIGH BIOMASS RICE Water Stress Selection Indices
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A Proposed Systemic Modeling Software for Jujube Fruit Cracking 被引量:3
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作者 Yanbin Hua Yuqin Song +3 位作者 Jie Li Caifang Tian Xin-Gen Zhou Liulin Li 《American Journal of Plant Sciences》 2015年第5期565-573,共9页
Jujube fruit cracking has become a major concern in jujube production. It can affect fruit quality and yield and crop productivity, resulting in significant economic loss. Recent advances in jujube fruit cracking rese... Jujube fruit cracking has become a major concern in jujube production. It can affect fruit quality and yield and crop productivity, resulting in significant economic loss. Recent advances in jujube fruit cracking research provide opportunities to improve our understanding of the impacts of environmental factors and plant physiological metabolism on jujube fruit cracking. In this article, we have developed a novel systemic modeling software for jujube fruit cracking. The potential function and value of this modeling software are presented. Current issues and future research directions in the modeling of jujube fruit cracking system are also discussed. To our knowledge, this is the first functional and/or integrated modeling software developed for the management of jujube fruit cracking. 展开更多
关键词 MODELING SOFTWARE JUJUBE FRUIT Cracking System CIRCADIAN CLOCK Metabolic Pathway MODELING
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