垂穗披碱草落粒性评价及农艺性状的相关性分析

为挖掘优异垂穗披碱草(Elymus nutans)种质资源,加快其抗落粒品种选育,本研究在前期资源筛选基础上,于2015-2016年对13份垂穗披碱草种质的落粒性及15个农艺性状进行了变异、相关性、主成分和聚类分析,并用隶属函数法对农艺性状进行了综合评价。结果表明,15个农艺性状中落粒率的变异系数最大,为57.43%,穗长的变异系数最小,为5.77%。13份种质中,PI619516落粒率最低,种柄断裂拉伸张力(breaking tensile strength,BTS)测定值达70.05gf,种质PI639855的落粒率最高,BTS值为13.99gf。BTS变异分析表明,种质PI639852的变异系数最大,为45.09%,表明该种质在落粒性方面存在较大的种内遗传差异。相关性分析表明,倒二叶长与旗叶长和旗叶宽,旗叶长与旗叶宽呈极显著正相关(P0.01),每穗小花数与穗长和茎粗呈显著正相关(P0.05),BTS与穗长和茎粗呈显著负相关(P0.05),表明穗长和茎粗越大,BTS就越小,落粒率就越高。以BTS值为变量的聚类分析结果表明,13份种质被聚为4类,第ⅰ类种质落粒性最高,第ⅱ和第ⅲ类种质表现出很高的落粒性,而第ⅳ类种质落粒性中等。15个农艺性状的综合聚类分析结果表明,13份种质被聚为4类。隶属函数分析表明,种质PI547394的综合性状表现优异,综合隶属函数值为0.55。本研究为垂穗披碱草育种提供了宝贵的遗传资源。

Assessment of seed shattering and analysis of agronomic traits in Elymus nutans

To understand its germplasm resources and promote breeding in Elymus nutans,variation coefficient,correlation-ship,principal component and cluster analyses were carried out on 15 agronomic traits of 13 accessions from 2015 to 2016.The results showed that the value of the seed shattering rate variation coefficient was the maximal(57.43%)and ear length was the minimum(5.77%)among 15 agronomic traits.PI619516 showed the best shattering resistance(breaking tensile strength,BTS =70.05 gf)among 13 accessions,while the shattering rate of PI639855(BTS =13.99 gf)was the highest.Variation analysis of BTS suggested that PI639852 had the largest variation(CV=45.09%),which indicated there was great genetic differentiation among individuals.Correlative analysis revealed high significantly positive correlation(P<0.01)between length of the second leaf from the inflorescence and flag leaf length,as well as flag leaf width;flag leaf width had a high significantly positive correlation(P<0.01)with flag leaf length.Florets per ear and ear length showed a significantly positive correlation(P<0.05),as well as stem diameter.Breaking tensile strength and ear length were significantly negatively correlated(P<0.05),as well as stem diameter,showing that the larger the ear length and stem diameter,the higher the shattering rate(BTS was smaller).Cluster analysis of BTS showed that 13 accessions were clustered into four groups.Group ⅰ showed the lowest shattering rate.Group ⅱ and ⅲ seed shattering were highest shattering rate.Group ⅳ seed shattering was medium cluster analysis for 15 agronomic traits showed that all accessions were clustered into four groups.The subordinate function analysis showed PI547396 had the best comprehensive performance with subordinate function value of 0.55.These screened materials are important for future breeding programs.