Full Length Research Paper

Bayesian mapping QTL for fruit and growth phenological traits in Lablab purpureus (L.) Sweet

Juan Yuan, Runqing Yang and Tianlong Wu*

School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai 200240, P. R. China.

*Corresponding author. E-mail: tianlongwu-26@163.com. Tel: +86-21-64789018. Fax: +86-21-58024666.

Accepted 17 December, 2008

In order to map the QTLs for the agronomic traits in Lablab purpureus (L.) Sweet, we designed an F₂ population derived from lablab accession (‘Meidou2012’ and ‘Nanhui23’) for construction of genetic linkage map and repeatedly measured three fruit traits (pod length, pod diameter and pod fresh thickness) and three growth phenological traits (flowering time, podding time and harvest maturity period) in F₂ population and F₃ lines from two planting years. Bayesian model selection was used to analyze main effect QTL, epistatic QTL and QTL by environment interactions (QEs) as well. 41 main effect QTLs (19 for fruit traits and 22 for growth phenological traits) were identified on 11 linkage groups with small phenotypic variances. Thirty nine pairs epistatic QTLs (19 for fruit traits and 20 for growth phenological traits) were also found which accounted for large proportions of phenotypic variations. And 11 QEs (8 for fruit traits and 3 for growth phenological traits) were detected only in F₃ lines. Six QTLs and one QEs were found to be pleiotropy. Pod length, pod diameter, pod fresh thickness, flowering time, podding time and harvest maturity period each had stable QTLs, which could be useful for breeding purposes and scientific reasoning.

Key words: Lablab, fruit traits, growth phenological traits, Bayesian model selection, interacting QTL, QEs.