Development Of Microsatellite Markers And Investigation Of Genetic Diversity In Vernicia Genus

The plant of Vernicia genus is one of the important non-edible oilseed sources and its seed oil is often considered as drying oils used in paints, varnishes, and for polymerization in industry. Recently, studies have also demonstrated that tung oil could be excellent feedstock for biodiesel production after blending with other biodiesel. Exploiting tung oil as feedstock of biodiesel is drawing great attention in China and South Asia. There are two species of the genus Vernicia: Vernicia montana Lour. and V. fordii (Hemsl.) Airy Shaw. They phylogenetically are very close and both native to southern China and southeastern Asia. Taxonomically, V. montana is easily distinguished from V. fordii by its inflorescence and fruit characters. Although V. fordii has been planted and tung oils have been used for hundreds of years in China, cultivation and utilization of V. montana is quite limited. According to our previous field survey and preliminary evaluation, V. montana gives much higher yields of tung oil than V. fordii. In particular, V. montana has been observed to be more vigorous and disease-resistant than V. fordii, and been successfully planted and replaced V. fordii in some hilly areas of South Yunnan, Vietnam and Thailand. It seems that V. montana has higher potential as biodiesel feedstock than V. fordii.In this study, we collected six individuals of V. fordii from three accessions and120individuals of V. montana from30indigenous V. montana accessions from different geographic areas in southwestern China and northern Laos. With molecular biology and biological information technology, Twenty two EST-SSR markers form EST database of V. fordii and twenty genome-SSR markers form V. montana using the Fast Isolation were developed by screening the genomic DNAs of120individuals of V. montana. The42SSR markers exhibited a moderate level of polymorphism in V. montana (He=0.553, PIC=0.490). Genetic relatedness investigation showed that there was not only distinct genetic differentiation among V. montana accessions (Fst=0.327, p<0.01) and also a distinct geographic pattern among V. montana accessions. The current study is the first report of development of SSRs and genetic relatedness investigation in Vernicia genus. These SSR markers reported herein will be valuable resources for future genetic studies, like construction of linkage maps, diversity analysis, quantitative trait locus/association mapping, and molecular breeding of tung tree. The genetic relatedness identified in V. montana would provide potential clue to choose germplasms in interest as progenitors for cross breeding and variety improvement of V. montana in practice.