Correlation analysis of test weight and other quality traits and candidate gene mining in 517 maize germplasms
[Objective]As an important factor of quality traits in national maize standard regional tests,test weight is a complex quantitative trait,and its influencing factor and regulatory mechanism is still unclear.Quality traits such as starch,protein,and fat content are important factors affecting test weight,but the relationship between them is still unclear.[Method]This research determined the test weight,starch,crude protein,gross fat,and amylose content of 517 maize germplasms mainly composed of local maize germplasm resources in Zhejiang Province.On the basis of correlation analysis,the kernels of four germplasms with higher test weight,higher starch content,lower protein content,lower fat content,and four germplasms with opposite phenotypes were selected for RNA-Seq analysis.[Result]By correlation analysis,this research found there was a significant positive correlation between test weight and starch content,while a negative correlation was found between test weight and protein or fat content.RNA-Seq analysis was performed for the extreme germplasm,a total of 159 differentially expressed genes were screened between 2 groups,and 8 candidate genes related to carbon metabolism or amino acid biosynthesis were used for further analysis.The expression difference of these genes was consistent with the change of test weight in different inbred lines by RT-qPCR.[Conclusion]The correlation between test weight and other quality traits was preliminarily clarified,providing superior germplasms and 8 candidate genes that play important roles in carbon reduction,endosperm development,starch metabolism,cellular metabolism,and seed fat accumulation for the selection of new high-quality maize cultivars.[Ch,4 fig.2 tab.40 ref.]
maizekernel test weightquality traitsregulation mechanism