Identification of molecular markers linked to trilocular gene (mc1) in Brassica juncea L.

Abstract

Multilocular plants generally have higher yield than bilocular plants, which is attributable to the difference in the number of seeds per silique. In this study, we investigated a landrace of Brassica juncea in China that has trilocular siliques. We discovered that two independent recessive genes (mc1 and mc2) controlled the trait of trilocular silique. Mc1 was preliminarily mapped using amplified fragment length polymorphism (AFLP) technology in combination with bulked segregant analysis. From a survey of 2,048 AFLP primer combinations, we obtained 24 AFLP markers linked to the target gene, of which five were successfully converted into sequence-characterized amplified region markers. Two of these five AFLP markers and two other AFLP markers shared high sequence homology with A07 in the Brassica rapa genome. We developed seven simple sequence repeat primer pairs based on their sequence homology with A07. Our result also demonstrated that EC14MC14 and SC20 are the closest markers flanking the Mc1 gene, at distances of 1.1 and 1.6 cM, respectively. These molecular markers will facilitate the fine mapping and cloning of the mc1 gene and accelerate the selection process for multilocular rapeseed through marker-assisted selection.