Mining candidate genes of grape berry cracking based on high density genetic map

Fruit cracking is a phenomenon in which the peel cracks during grape berry development, which seriously affects the yield and quality of the fruit. However, there are few studies on the mining of candidate genes related to berry cracking. In order to better understand the genetic basis of berry cracking, we used the results of previous quantitative trait locus (QTL) mapping, combined with field surveys of berry-cracking types and the berry-cracking rate, to mine candidate berry-cracking genes. The results showed that three identical QTL loci were detected in two years (2019 and 2020); and three candidate genes were annotated in the QTL interval. In mature berries, the expressions of the candidate genes were more abundant in the cracking-susceptible parent (‘Crimson Seedless’) than in the cracking-resistant parent (‘Muscat Hamburg’). Grape berry cracking is a complex trait controlled by multiple genes, mainly including genes encoding cellulose synthase–like protein H1, glucan endo-1,3-beta-glucosidase 12, and brassinosteroid insensitive 1-associated receptor kinase 1. The high expression of the candidate berry-cracking genes may promote the occurrence of berry cracking. This study helps elucidate the genetic mechanism of grape berry cracking.