不同生态因子条件下西藏青稞种子表型性状的相关分析

为了研究西藏青稞种质籽粒遗传变异程度、变异规律、地理因子对籽粒表型性状的影响程度,确定决定籽粒表型的关键性状,从而为青稞育种提供籽粒表型基础模型,本研究以527份西藏青稞农家种、野生近缘种为试验材料,基于青稞籽粒表型性状变化和相关地理环境因子,采用数字图像分析法对西藏青稞农家种、野生近缘种等527份青稞种质资源籽粒长、粒宽、粒长宽比、粒面积、圆度值、密度指数和千粒重(TKW)7个表型性状进行精确测量,并进行典型相关分析、聚类分析和主成分分析。结果表明,西藏青稞种子表型存在广泛的变异类型,TKW的变异系数最大,粒长的变异系数最小。典型相关分析显示,海拔、经度和纬度地理因子与7个籽粒表型性状间存在着显著相关关系(α=0.05),海拔高度的增加可使青稞粒面积、粒长宽比、粒圆度值增加,而粒长逐渐减少。纬度和经度的增加与粒长呈正相关,并与TKW有一定联系。籽粒7个表型性状的聚类分析表明,527份青稞材料可聚为3大类群,各类群表现一定的地理分区。主成分分析显示,青稞籽粒TKW、面积、粒宽、粒密度可代表7个籽粒表型性状的变异,且表现出以粒宽、TKW、粒面积为主反映种子大小的指标及以长宽比、粒长、圆度值为主反映种子形状的指标。西藏青稞种质资源籽粒表型变异极为丰富,并与多变的地理因子显著相关。青稞籽粒表型性状可分为种子大小和种子形状2个方面,两者对千粒重贡献率分别达到60.3%和33.8%,且表现为独立遗传特性,这说明在今后的青稞育种工作中,应以籽粒大小指标为重,兼顾籽粒形状,该研究结果为西藏青稞高产栽培育种提供了一定的理论依据。

Phenotypic Correlation Analysis of Hullessbarley Kernel Traits Form Tibet Plateau Region Under the Condition of Different Ecological Environment

In order to clarify the influences of heritable variation degree,variation pattern and geographical factors of germplasm and grain of Tibet highland hullessbarley on grain phenotypic characters,define the critical characters determining the grain phenotype and provide a fundamental model of grain phenotype for the breeding of Tibet highland hullessbarley,this study employed 527 material form Local cultivar and wild relatives of hullessbarley,precisely measured seven phenotypic characters including grain length,grain width,grain length-to-width ratio,grain area,grain roundness,density index and thousand seed weight (TKW) of 527 germplasm resources of cultivated and wild sibling Tibet highland hullessbarley by means of digital image analysis accoroling to the grain phenotypic character changes and relevent geographical factors of germplasm resources of Tibet highland hullessbarely.Typical correlation analysis,clustering analysis,principal component analysis were conducted using SPSS20 and R language software.Results showed that grain phenotype of Tibet highland hullessbarley had wide variation types,with the variable coefficient of TKW being the biggest and that of the grain length being the smallest.Geographical factors such as elevation,longitude and latitude had significant correlation with seven grain phenotypic characters by canonical correlation analysis (α =0.05) . The increase of elevation increased the grain size,grain length-width ratio and grain roundness while decreasing the grain length.The increase of longitude and latitude showed positive correlation with the grain length and certain relation with the TKW.According to the clustering analysis of seven phenotypic characters,these 527 highland hullessbarley materials could be classified into 3 groups,with each in a certain geographical zone.The principal component analysis indicated that the TKW,grain area,grain width and grain density of highland hullessbarley can represent the seven phenotypic characters in terms of variation,and grain width,thousand seed weight and grain area mainly to indicate grain sizes and the other group of length-width ratio,grain length and roundness mainly to indicate grain shapes.This research showed that germplasm resources of Tibet highland hullessbarley have rich grain phenotypic variation which has significant correlation with changeable geographical factors.The phenotypic characters of highland hullessbarley can be divided into one group of with contribution rates of 60.3％ and 33.8％ respectively,and showed independent hereditary characters.The indicators of grain sizes should be emphasized firstly before considering those of grain shapes during the future breeding of highland hullessbarley.This study provides a theoretical basis for the breeding of high yield cultivation of hullessbarley in Tibet