摘要：

为明确小麦茎秆基部第2节形态及结构特征与抗倒伏关系,发掘抗倒伏关键茎秆形态指标及数量性状基因座位点(QTL)。以120份RILs家系为研究材料,分别测定2020,2021年茎秆强度及基部第2节间长度、茎粗、壁厚、纤维素含量和木质素含量等指标,开展多元回归分析,并结合55K SNP芯片进行QTL定位分析。结果表明,茎秆强度与基部第2节间茎粗和壁厚呈显著或极显著(P<0.01)正相关(P<0.05),与基部第2节间纤维素含量和木质素含量呈极显著正相关(P<0.01)。多元回归分析表明,基部第2节间纤维素含量是影响小麦茎秆强度的关键指标。基于55K芯片关联分析结果,在1A、1D、2B、2D、4D、5A、5B、5D和7B等染色体上共检测到19个与茎秆性状相关的QTLs,解释了7.67%~65.33%的表型变异。在1D染色体上,与标记AX-110771095和AX-109431570连锁的QTL位点同时控制基部第2节间长、壁厚及纤维素含量3个性状,解释了7.96%~10.76%的表型贡献率。

关键词: 小麦, 茎秆强度, QTL定位, 倒伏, 多元回归分析

Abstract:

In order to clarify the relationship between the morphological and structural characteristics of stem basal node 2 and lodging resistance in wheat,we explored key stem morphological indicators and Quantitative trait loci(QTL)sites for lodging resistance.120 RILs families were selected as research materials,and stem strength,basal second internode length,stem diameter,wall thickness,cellulose content and lignin content were measured in 2020 and 2021,respectively.Multiple regression analysis and QTL locations were performed by combining 55K SNP data.The results showed that the stem strength was significantly or extremely significantly positively correlated with the stem diameter and wall thickness of the second basal internode,and was extremely significantly positively correlated with the cellulose content and lignin content of the second basal internode.Multiple regression analysis showed that cellulose content in basal second internode was the key index affecting stalk strength of wheat.A total of 19 QTLs related to stem traits were detected on chromosomes 1A,1D,2B,2D,4D,5A,5B,5D and 7B,explaining 7.67% to 65.33% of the phenotypic variation.On chromosome 1D,the QTL linked to AX-110771095 and AX-109431570 simultaneously controlled the basal second internode length,wall thickness and cellulose content,explaining the phenotypic contribution of 7.96%-10.76%.

Key words: Wheat, Stalk strength, QTL mapping, Lodging, Multiple regression analysis