育成青稞品种的粒型性状的非条件与条件关联分析

Unconditional and Conditional Association Mapping of Grain Shape Trait in Hulless Barley

籽粒粒型性状在优质高产大麦育种过程中是一种重要的目标性状。为了了解中国青藏高原青稞育成品种中籽粒性状的表型及遗传特征,本研究以60份青稞育成品种为材料,对其各个品种的粒长、粒宽和千粒重3个性状进行了考察,利用TASSEL软件中的MLM模型对籽粒的3个粒型性状进行了条件和非条件关联分析,并利用BSA方法对影响粒型性状的位点进行了发掘。结果表明,青稞育成品种间存在丰富的籽粒粒型变异。分别发现了8个、7个与13个SRAP标记与粒宽、粒长与千粒重呈显著关联,其中的6个SRAP位点在条件关联分析中也被发现,条件关联分析的结果表明青稞千粒重受粒宽的影响大于受粒长影响较小。相关性分析也得到相似结果。同时利用BSA方法,检测到了80个SRAP标记与粒型性状相关,其中的6个标记在非条件关联分析中找到。这些结果可以为青稞的籽粒粒型改良和高产青稞育种提供帮助。

Grain shape and related trait were important target traits at the breeding process of new hulless barley with high-yield and well quantify character. In order to understand the genetic and phenotypic basis of the grain shape and related traits in developed hulless barley cultivars from Qinghai-Tibet Plateau. A set of 60 developed cultivars of hulless barley was used for investigating the morphology of the grain length, grain width and thousand kernel weight. Unconditional and conditional association mapping analysis were performed by using the mixed line model as implemented in TASSEL software, while bulk sample analysis（BSA） methodology was also employed to identify the marker significantly associated with grain shape traits. The results demonstrated that the genetic variation of grain shape trait was rich in developed hulless barley cultivars from Qinghai-Tibet Plateau 8, 7, 13 SRAP markers significantly associated with grain width, grain length and thousand kernel weight. Among them, 8 SRAP markers were detected in conditional association mapping study. Conditional association mapping showed that the effect of grain width is larger than gr ain length in expression of the thousand kernel weight trait from hulless barley. The same result was also identified in correlation analysis. 6 of 80 markers which affected the expression of grain shape trait by using the BSA methodology were also detected in the unconditional association mapping. Those results might be valuable for improving grain shape trait and cultivate high-yield accession in hulless barley.