镉胁迫下甜、糯玉米开花期性状的全基因组关联分析

以183份甜、糯玉米自交系构成的关联群体为材料,在2种Cd污染水平下对甜、糯玉米开花期(DA,days to anthesis)、吐丝期(DS,days to silking)和开花吐丝间隔(ASI,anthesis silking interval)进行全基因组关联分析,以揭示重金属Cd胁迫对甜、糯玉米开花期的影响及调控基因。结果表明:不同Cd污染水平对甜、糯玉米DA和DS均产生影响,其中对DS的延长更为明显,从而导致ASI的增大。同时,甜玉米ASI平均值高于糯玉米ASI,由此表明甜玉米ASI对重金属Cd胁迫更为敏感。结合群体基因型和开花期相关性状表型的全基因组关联分析,分别筛选到3个开花期相关的SNP位点和6个吐丝期相关的SNP位点。根据其所对应的物理位置与Maize GDB和NCBI基因数据库进行比对,预测获得8个已知功能基因,其中包括在前人研究中与玉米开花期有关的候选基因。以上研究解析甜、糯玉米在重金属Cd污染水平下开花期及吐丝期的遗传规律,为今后开展甜、糯玉米分子标记辅助育种和Cd安全品种的选育提供参考。

Genome Wide Association Analysis of Flowering Traits in Sweet and Waxy Maize under Cadmium Stress

In this study,183 sweet and waxy maize inbred lines were subjected to analyze the flowering time(DA,days to anthesis),silking time(DS,days to silking)and Anthesis silking interval(ASI)under Cdpolluted environments,in order to reveal the response and possible regulatory genes at the flowering stage.The results showed that Cd pollution prolonged DA and DS of sweet and waxy maize,especially for DS,which led to the increasing of ASI.The ASI value of waxy maize was found to be lower than that of sweet maize,implying the sensitivity of sweet corn under Cd stress.Three and six SNPs,which were associated with flowering time and silking time,respectively,were detected by Genome-wide association analysis(GWAS).These SNPs were found to be associated with eight genes annotated in maize GDB and NCBI gene databases,including few genes which were reported roles in the flowering time.Collectively,these results might provide theoretical reference for molecular marker assisted breeding and Cd safe breeding of sweet and waxy maize varieties in the future.