叶面积指数Leaf Area Index(LAI)作为植被生物量指标之一,耕作区LAI不仅能反映作物的长势动态,且与农业生态、作物产量密切相关。本文通过对2001—2017年中国农田区域的MODIS-LAI长时序数据进行重建,利用Mann-Kendall检验、变异系数、...叶面积指数Leaf Area Index(LAI)作为植被生物量指标之一,耕作区LAI不仅能反映作物的长势动态,且与农业生态、作物产量密切相关。本文通过对2001—2017年中国农田区域的MODIS-LAI长时序数据进行重建,利用Mann-Kendall检验、变异系数、重心迁移模型等方法分析了中国耕作区LAI的时空变化特征。结果表明:①中国耕作区LAI在2001—2017年显波动式上升,且与农作物单产相关系数高达0.91;②不同耕作区季节差异显著,夏季>秋季>春季>冬季,夏季平均为1.54,生长季平均为1.13,秋季平均为0.78,春季平均为0.63,冬季平均为0.31;③2001—2012年二熟、三熟区LAI变化平缓,2012年后有上升趋势但未发生明显突变;一熟区2006年之前处于平稳上升状态,2006年之后发生突变上升趋势显著;④研究时段内我国长江以北的耕作区LAI变异程度较为突出,最高达4.12;5农田面积重心经历了先向西南迁移,后再向西北迁移过程,农田生长季LAI重心相对于农田面积重心变幅较大,经历了南北波动式向西部迁移过程,迁移距离分别为82.78 km、90.53 km。展开更多
目的利用荧光标记辅助的扩增片段长度多态性(amplified fragment length polymorphism,AFLP)技术,从基因组DNA水平上分析我国6个栽培生产区域52份枸杞Lycium chinense样本的遗传多样性。方法对提取的枸杞DNA样本进行酶切、连接、预扩增...目的利用荧光标记辅助的扩增片段长度多态性(amplified fragment length polymorphism,AFLP)技术,从基因组DNA水平上分析我国6个栽培生产区域52份枸杞Lycium chinense样本的遗传多样性。方法对提取的枸杞DNA样本进行酶切、连接、预扩增和选扩增等步骤,扩增产物经毛细管电泳系统分离和数据采集后,利用Popgene软件计算遗传多样性参数,利用GenAlex软件计算遗传距离并进行主坐标分析,利用MEGA-X软件根据遗传距离进行聚类分析,利用Structure软件进行群体遗传结构分析。结果共筛选得到10对AFLP选择性扩增引物组合,扩增得到328条扩增片段,其中多态性片段121条,且在不同产地枸杞居群间多态性位点分布不均匀。分析显示不同栽培产区枸杞的遗传多样性较低,等位基因数(observed number of alleles,Na)、有效等位基因数(effective number of alleles,Ne)、观测杂合度(Nei’s gene diversity,H)和香浓信息指数(Shannon information index,I)分别为1.4380、1.2316、0.1407和0.2152,Nei’s遗传相似性范围为0.8354~0.8902。结论不同栽培生产区域的枸杞居群间存在较为频繁的基因交流,遗传分化程度中等。居群内部遗传变异是枸杞遗传变异的主要来源,居群间遗传变异不显著,同时遗传距离与地理距离没有明显相关性。可为枸杞的遗传背景信息积累、引种栽培、种质资源保护、核心种质库构建以及可持续开发策略的制定和管理提供科学依据。展开更多
目的:建立同时测定不同栽培区域滁菊中绿原酸、木犀草苷、异绿原酸A、异绿原酸C、黄芩苷、槲皮素、木犀草素、芹菜素等8种成分含量的方法。方法:采用ZORBAX Eclipse Plus C18色谱柱(4.6mm×250mm,5μm);流动相为乙腈-0.1%磷酸溶液,...目的:建立同时测定不同栽培区域滁菊中绿原酸、木犀草苷、异绿原酸A、异绿原酸C、黄芩苷、槲皮素、木犀草素、芹菜素等8种成分含量的方法。方法:采用ZORBAX Eclipse Plus C18色谱柱(4.6mm×250mm,5μm);流动相为乙腈-0.1%磷酸溶液,梯度洗脱,流速0.8mL/min,紫外检测波长为327nm,检测不同区域滁菊中8种成分含量。结果:不同栽培区域滁菊中氯原酸等8种成分的线性关系良好,平均回收率在94.57%～100.01%之间,RSD均小于3%。结论:该方法具有良好的灵敏度、重现性和回收率,可用于滁菊中8种成分的同时测定。展开更多
[ Objective ] The paper was to study the occurrence and damage regularity of tobacco cutworm moth （Spodoptera Litura Fabricius） in low-altitude area in Lincang city. [ Method] The adult sex attractant monitoring, fi...[ Objective ] The paper was to study the occurrence and damage regularity of tobacco cutworm moth （Spodoptera Litura Fabricius） in low-altitude area in Lincang city. [ Method] The adult sex attractant monitoring, field investigation of occurrence and damage, and observation of continuous generation development of natural populations were carried out in natural flue-cured tobacco fields. [ Result] In field growth period of flue-cured tobacco under low-altitude of 1 000 - 1300 m, tobacco cutworm moth occurred for 4 generations, the duration of each generation was about 33 d, and the main injurious generation was the third generation. [ Conclusion] The paper provided reference for comprehensive control of tobacco cutworm moth in the low altitude areas.展开更多
In the wake of global water scarcity, forecasting of water quantity and quality, regionalization of river basins has attracted serious attention of the hydrology researchers. It has become an important area of researc...In the wake of global water scarcity, forecasting of water quantity and quality, regionalization of river basins has attracted serious attention of the hydrology researchers. It has become an important area of research to enhance the quality of prediction of yield in river basins. In this paper, we analyzed the data of Godavari basin, and regionalize it using a cluster ensemble method. Cluster Ensemble methods are commonly used to enhance the quality of clustering by combining multiple clustering schemes to produce a more robust scheme delivering similar homogeneous basins. The goal is to identify, analyse and describe hydrologically similar catchments using cluster analysis. Clustering has been done using RCDA cluster ensemble algorithm, which is based on discriminant analysis. The algorithm takes H base clustering schemes each with K clusters, obtained by any clustering method, as input and constructs discriminant function for each one of them. Subsequently, all the data tuples are predicted using H discriminant functions for cluster membership. Tuples with consistent predictions are assigned to the clusters, while tuples with inconsistent predictions are analyzed further and either assigned to clusters or declared as noise. Clustering results of RCDA algorithm have been compared with Best of k-means and Clue cluster ensemble of R software using traditional clustering quality measures. Further, domain knowledge based comparison has also been performed. All the results are encouraging and indicate better regionalization of the Godavari basin data.展开更多
文摘叶面积指数Leaf Area Index(LAI)作为植被生物量指标之一,耕作区LAI不仅能反映作物的长势动态,且与农业生态、作物产量密切相关。本文通过对2001—2017年中国农田区域的MODIS-LAI长时序数据进行重建,利用Mann-Kendall检验、变异系数、重心迁移模型等方法分析了中国耕作区LAI的时空变化特征。结果表明:①中国耕作区LAI在2001—2017年显波动式上升,且与农作物单产相关系数高达0.91;②不同耕作区季节差异显著,夏季>秋季>春季>冬季,夏季平均为1.54,生长季平均为1.13,秋季平均为0.78,春季平均为0.63,冬季平均为0.31;③2001—2012年二熟、三熟区LAI变化平缓,2012年后有上升趋势但未发生明显突变;一熟区2006年之前处于平稳上升状态,2006年之后发生突变上升趋势显著;④研究时段内我国长江以北的耕作区LAI变异程度较为突出,最高达4.12;5农田面积重心经历了先向西南迁移,后再向西北迁移过程,农田生长季LAI重心相对于农田面积重心变幅较大,经历了南北波动式向西部迁移过程,迁移距离分别为82.78 km、90.53 km。
文摘目的利用荧光标记辅助的扩增片段长度多态性(amplified fragment length polymorphism,AFLP)技术,从基因组DNA水平上分析我国6个栽培生产区域52份枸杞Lycium chinense样本的遗传多样性。方法对提取的枸杞DNA样本进行酶切、连接、预扩增和选扩增等步骤,扩增产物经毛细管电泳系统分离和数据采集后,利用Popgene软件计算遗传多样性参数,利用GenAlex软件计算遗传距离并进行主坐标分析,利用MEGA-X软件根据遗传距离进行聚类分析,利用Structure软件进行群体遗传结构分析。结果共筛选得到10对AFLP选择性扩增引物组合,扩增得到328条扩增片段,其中多态性片段121条,且在不同产地枸杞居群间多态性位点分布不均匀。分析显示不同栽培产区枸杞的遗传多样性较低,等位基因数(observed number of alleles,Na)、有效等位基因数(effective number of alleles,Ne)、观测杂合度(Nei’s gene diversity,H)和香浓信息指数(Shannon information index,I)分别为1.4380、1.2316、0.1407和0.2152,Nei’s遗传相似性范围为0.8354~0.8902。结论不同栽培生产区域的枸杞居群间存在较为频繁的基因交流,遗传分化程度中等。居群内部遗传变异是枸杞遗传变异的主要来源,居群间遗传变异不显著,同时遗传距离与地理距离没有明显相关性。可为枸杞的遗传背景信息积累、引种栽培、种质资源保护、核心种质库构建以及可持续开发策略的制定和管理提供科学依据。
文摘目的:建立同时测定不同栽培区域滁菊中绿原酸、木犀草苷、异绿原酸A、异绿原酸C、黄芩苷、槲皮素、木犀草素、芹菜素等8种成分含量的方法。方法:采用ZORBAX Eclipse Plus C18色谱柱(4.6mm×250mm,5μm);流动相为乙腈-0.1%磷酸溶液,梯度洗脱,流速0.8mL/min,紫外检测波长为327nm,检测不同区域滁菊中8种成分含量。结果:不同栽培区域滁菊中氯原酸等8种成分的线性关系良好,平均回收率在94.57%～100.01%之间,RSD均小于3%。结论:该方法具有良好的灵敏度、重现性和回收率,可用于滁菊中8种成分的同时测定。
基金Supported by Project of China National Tobacco Corporation Yunnan Branch( 2010YN77)
文摘[ Objective ] The paper was to study the occurrence and damage regularity of tobacco cutworm moth （Spodoptera Litura Fabricius） in low-altitude area in Lincang city. [ Method] The adult sex attractant monitoring, field investigation of occurrence and damage, and observation of continuous generation development of natural populations were carried out in natural flue-cured tobacco fields. [ Result] In field growth period of flue-cured tobacco under low-altitude of 1 000 - 1300 m, tobacco cutworm moth occurred for 4 generations, the duration of each generation was about 33 d, and the main injurious generation was the third generation. [ Conclusion] The paper provided reference for comprehensive control of tobacco cutworm moth in the low altitude areas.
文摘In the wake of global water scarcity, forecasting of water quantity and quality, regionalization of river basins has attracted serious attention of the hydrology researchers. It has become an important area of research to enhance the quality of prediction of yield in river basins. In this paper, we analyzed the data of Godavari basin, and regionalize it using a cluster ensemble method. Cluster Ensemble methods are commonly used to enhance the quality of clustering by combining multiple clustering schemes to produce a more robust scheme delivering similar homogeneous basins. The goal is to identify, analyse and describe hydrologically similar catchments using cluster analysis. Clustering has been done using RCDA cluster ensemble algorithm, which is based on discriminant analysis. The algorithm takes H base clustering schemes each with K clusters, obtained by any clustering method, as input and constructs discriminant function for each one of them. Subsequently, all the data tuples are predicted using H discriminant functions for cluster membership. Tuples with consistent predictions are assigned to the clusters, while tuples with inconsistent predictions are analyzed further and either assigned to clusters or declared as noise. Clustering results of RCDA algorithm have been compared with Best of k-means and Clue cluster ensemble of R software using traditional clustering quality measures. Further, domain knowledge based comparison has also been performed. All the results are encouraging and indicate better regionalization of the Godavari basin data.
