Leaf morphology and soft rot resistance in offspring of a somatic hybrid between Chinese cabbage and kale (Cruciferae)

Abstract

Variations in leaf morphology and soft rot resistance were investigated in offspring of a somatic hybrid between Chinese cabbage (2n=20) and wild kale (2n=18). Concerning leaf morphology, self-fertilized offspring of the somatic hybrid (2n=38) had a mean value intermediate between Chinese cabbage and kale in only one of the three indices used for comparison. Backcrossed offspring of the somatic hybrid with Chinese cabbage had intermediate mean values between Chinese cabbage and self-fertilized offspring of the somatic hybrid, but there was much larger variation within the backcross population. As to soft rot, Chinese cabbage was susceptible, and wild kale resistant. Self-fertilized and open-pollinated offspring of the somatic hybrid had intermediate mean values of the parental species and large variations of the symptoms. The backcrossed offspring were rather susceptible but showed continuous variation. In the backcrossed progeny, no correlation was observed between resistance and leaf morphology. It is hypothesized that recombinants having soft rot resistance from kale in combination with leaf morphology of Chinese cabbage will segregate in later generations.