黄淮麦区部分小麦和国外引进小麦GS2等位基因的检测及其与农艺性状的关联分析

为明确黄淮麦区TaGS2等位基因的分布状况及其与主要农艺性状的关系,对黄淮麦区2008年之前育成的种质材料、新育成的品种(系)及国外引进材料,用TaGS2-A1、TaGS2-B1和TaGS2-D1等功能标记鉴定对应的基因,并结合相关农艺性状发掘优势单倍型。结果表明,黄淮麦区2008年之前育成的种质材料和新育成品种(系)中TaGS2等位基因分布频率存在一定的差异;TaGS2-A1b、TaGS2-B1b和TaGS2-D1a是优势TaGS2等位基因,TaGS2-A1b在小麦抽穗期、株高和小穗数的改良上是优势单倍型,但在新育成的品种(系)中有下降的趋势,TaGS2-D1a能够显著增加小穗数、穗粒数和穗粒重,在各类材料中的比例都较高;TaGS2-B1b是提高千粒重的优势单倍型。因此,在黄淮麦区小麦穗部性状改良中TaGS2-B1b和TaGS2-D1a的作用显著,尤其是TaGS2-D1a,同时黄淮麦区种植小麦遗传多样性在减少,一些优势单倍型未受到重视,应对地方品种和一些国外引进材料加以利用。

Allelic Variations ofTaGS2 Genes and Their Association with Agronomic Traits in Whaet Cultivars from Huang-Huai Wheat Region in China and Overseas

Glutamine synthetase (GS) plays a key role in the nitrogen (N) use and yield potential of bread wheat. Investigating the haplotypes inTaGS2 genes and their associations with agronomic traits may be a useful approach for improving wheat yield and N-use efficiency. In this study,278 elite wheat varieties from Huang-Huai winter wheat region and 57 introduced varieties were used to discover the frequencies ofTaGS2 haplotypes and the association betweenTaGS2 and agronomic traits,in addition,corresponding allelic variants were also identified using the function markers ofTaGS2 genes. The results indicated that the frequency of allelic variation ofTaGS2 genes detected were different between those wheat varieties,three favorableTaGS2 haplotypes (TaGS2-A1b, TaGS2-B1b andTaGS2-D1a) were revealed,but the frequencies of TaGS2-A1b andTaGS2-B1b among varieties in different years presented a downward trend. TaGS2-A1b was considered as a potential haplotype for improving heading date,plant height and spikelet number per ear, TaGS2-D1a was associated with significantly higher values in spikelet number per ear,grain number per ear and grain weight per ear,whileTaGS2-B1b was a potential superior haplotype for increasing 1 000-grain weight,nevertheless, TaGS2-D1a for improving spike traits may be more valued by many breeders. In the Huang-Huai wheat region,the genetic diversity of wheat varieties was reducing,so we should pay more attention to landrace and some introduced varieties.