To identify the physiological function of Diacylglycerol Acyltransferase 2 (DGAT2) coding gene in the process of tung oil biosynthesis, DGAT2 was cloned from cDNA of tung tree kernel and then linked with pMD18-T vector for sequencing. The 969bp fragment containing Open Reading Frame was acquired. Subsequently, RNAi binary expression vector pD35-DGAT2 was constructed, which expressed DGAT2 in two opposite ways. The studies provide the possibilities to further identify the function of DGAT2 in tung oil biosynthesis by RNAi technology and hold promise for genetic engineering of Venicia fordii.
The annual growth rhythm of Litsea cubeba seedling was studied. The average thousand-grain weight of L. cubeba was 35 g, and the germination rate was higher than 70%. The results of cluster analysis showed that, the growth period could be divided into 4 stages, i.e. the stage of seedling emergence (from March 2 to March 17), the initial stage of growth (from March 18 to May 31), the vigorous growth stage (from June 11 to August 29) and the late growth stage (from August 30 to December 27). The height and diameter of one-year-old seedling were fit with logistic curve law, and the growth process followed a "slow-fast-slow" curve. The equation of average daily growth showed that the fastest growth appeared in July which had the highest monthly average temperature. This conclusion provided a reference for the seedling stage management of L. cubeba forest. The authors recommend vigorously developing L. cubeba forest in the mountainous area of Guizhou Province, and providing scientific and technological support to the forest tenure reform.