Expression Profile And Genome-Wide Association Analyze of Silique Length In Brassica Napus L.

Abstract Background: Silique length (SL) is an important trait tightly related to seed yield in Brassica napus (B. napus). Many studies related to SL have been reported in B. napus, but only a few candidate genes have been found and cloned, and the regulatory mechanism of SL is not clear. Results: We identified QTL for SL by using a RIL population and two independent GWAS populations. Major QTL on A07, A09, and C08 chromosome were stably detected in all environments from all populations. As important candidate genes, several genes related to starch and sucrose metabolism, plant hormone signal transmission and phenylpropanoid biosynthesis were detected in the main QTL interval. Such as, BnaA9.CP12-2, BnaA9.NST2, BnaA7.MYB63, BnaA7.ARF17, etc. At the same time, the results of RNA-seq and WGCNA showed that starch and sucrose metabolism, photosynthesis, and secondary cell wall biosynthesis played an important role in the development of siliques. Conclusions: we propose that photosynthesis, sucrose and starch metabolism, plant hormones, and lignin content play an important role in the development of rapeseed silique.