Identification of Molecular Markers for Tobacco Brown Spot Resistant Genes through Association Analysis

In order to screen for SSR markers associated with tobacco brown spot resistant genes and to provide useful information for breeders, 404 SSR markers were used to scan polymorphism among a population containing 96 tobacco germplasms in this study. Population structure was analyzed and association analysis between disease index and SSR markers were performed using TASSEL 2.1. 38 SSR markers were identified as being associated with resistant genes at the level of P≤0.01. The results also indicated that PT60236, PT50668, PT50176, PT53770, PT60080 and PT50727 were tightly associated with resistant genes. These SSR markers were located in the 6th, 8th, 9th, 19th, 3th, 23th tobacco linkage group respectively. The markers identified in this study are useful in molecular marker assisted selection in tobacco breeding programs for brown spot resistance.