Genetic analysis and molecular markers associated with multi-gynoecia (Mg) gene in Trigrain whea

Trigrain wheat normally produces up to three gynoecia in a single floret and forms three close-set grains. The gene conferring the multi grain phenotype was earlier designated Mg, the multiple gynoecia gene. Different genetic patterns controlling this trait have been reported. In the present work we studied the inheritance of the three grains trait and identified simple sequence repeats (SSR) markers linked to the Mg gene. Segregation analysis in the cross IGDB-TW (trigrain wheat)/Chinese Spring confirmed that a single dominant gene controlled the three grains trait. An allelism test showed that the same gene controlled the trigrain trait in line Trigrain-Yin 1. A total of 339 microsatellite markers were tested for polymorphism by bulked segregation analysis (BSA) in an F2 population. Six microsatellite markers, Xcfd233, Xgdm6, Xgdm87, Xgwm311, Xgwm349 and Xgwm539, on chromosome 2DL, were linked to Mg. Using the CS 2D deletion lines, Mg gene was localized to the distal region of chromosome 2DL. The microsatellite markers identified in this study have the potential for further mapping and map-based cloning of the gene.Key words: Simple sequence repeats, physical mapping, trigrain wheat