The tung tree is an important non-edible oilseed source, and its seed oil is often considered as drying oils used in paints and varnishes, and for polymerization in industry. There are two species of tung trees: Vernicia montana Lour. and Vernicia fordii (Hemsl.) Airy Shaw, both native to southern China and southeastern Asia. Exploiting tung oil as feedstock of biodiesel is drawing great attention in China and South Asia. To use tung oil from oilseeds of V. montana for producing biodiesel, it is crucial to develop high-productivity varieties.

 Xishuangbanna Tropical Botanical Garden (XTBG) had initiated the program “Collection and Improvement of Germplasm for V. montana” since 2006 to develop high-productivity varieties as biodiesel plant. Seeds or seedlings of 30 indigenous accessions were collected from open forests covering the main distribution areas of V. montana in China and planted at XTBG. These accessions represent the main resources of V. montana distributed in China.

Investigating the genetic diversity and relatedness among germplasms is necessary to serve breeding and improvement of varieties. However, little is known about molecular markers developed for tung trees.

 Prof. LIU Aizhong and his research team of XTBG developed a set of expressed sequence tag-simple sequence repeat (EST-SSR) markers for tung trees based on EST sequences of V. fordii and further assessed the genetic diversity and relatedness among tung tree accessions collected at XTBG using SSR markers available.

The researchers reported 22 novel EST-SSR markers which represented a valuable resource for future genetic studies in tung trees, like construction of linkage maps, genetic diversity analysis at the population level, quantitative trait locus/association mapping, and molecular breeding of the tung tree. The EST-SSR markers exhibited a moderate level of polymorphism in tung trees and were used to establish genetic relatedness among 30 accessions of V. montana and three accessions of V. fordii.

The genetic differentiation identified among accessions would favor breeding and variety improvement of tung trees in practice.

The study entitled “Development of EST-SSR markers and investigation of genetic relatedness in tung tree” has been published in Tree Genetics & Genomes, 8 (4):993-940, DOI: 10.1007/s11295-012-0481-z