Whole genome map of zha cai successfully mapped

Whole gene map of zha cai successfully mapped: telling you why zha cai has a unique "Chinese flavor"

Recently, the team of Professor Zhang Mingfang from the Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, used high-throughput sequencing technology to map the world's first whole genome map of zha cai, which will be of great significance to the improvement of mustard vegetable crops.

Vegetable mustard is an important processed vegetable in China, and zha cai, potherb mustard and kohlrabi all belong to different varieties. Through high-throughput sequencing technology, combined with the constructed high-density genetic map, Zhang Mingfang's research group completed for the first time a high-quality genome map of the allotetraploid zha cai (AABB genome) in Brassica, and further enriched and deepened the understanding of the "family tree" of zha cai. The study found that the mustard species formed 39,000 to 55,000 years ago, with a single geographical origin; its A subgenome is more closely related to Brassica rapa, and then evolved into two main groups: vegetable mustard and oil mustard.

Why do zha cai and mei gan cai have a unique "Chinese flavor"? The research group found two sets of homologous gene sequences, one of which is related to glucosinolate metabolism; they underwent differentiated evolution, which is why some zha cai smells fragrant while others do not have an obvious aroma. The other set is related to lipid metabolism, determining the oil yield and lipid composition of oil mustard. Yang Jinghua, associate professor and first author of the paper, introduced that for half a century, many scholars have used wheat, cotton, rapeseed and others as model crops to conduct extensive research on complex genome assembly and homologous gene expression, but had not yet revealed the mechanism of homologous gene expression and selection in polyploid species. This mechanism has finally been revealed through China's "native" crop zha cai: asymmetric evolution occurs between the subgenomes of allotetraploid mustard, and genes with significant expression differences among homologous genes between subgenomes show faster evolutionary rates; these genes have been selected during the differentiation of vegetable and oil mustard.