Abstract

Leaf color inheritance in Brassica juncea was studied in F₁, F₂ and BC₁populations. Leaf color was found to be under the control of gene, and the purple leaf trait was dominant over the green leaf trait. Segregation analysis reveal that one pair of gene controlled the leaf color. To develop markers linked to the leaf color gene, SRAP (sequence-related amplified polymorphism) combined with BSA (bulked segregant analysis) technology was used to screen the parents and bulks were selected randomly from an F₂ population (Ziye × Lvye) consisting of 192 individuals. From a survey of 170 SRAP primer combinations, 3 SRAP markers linked to leaf color gene were identified, and the average distance between markers was 3.3 cM. The closet markers (ME7EM9 and ME2EM2) were at a distance of 1.2 and 5.5 cM from the target gene, respectively. The leaf color trait controlled by a single dominant gene together with the available molecular markers will greatly facilitate the future breeding of purple leaf varieties. The markers found in this study could accelerate the step of map-based cloning of the target gene.

Key words: Brassica juncea, leaf color, inheritance, sequence-related amplified polymorphism (SRAP).