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.

Understanding the seed dormancy and germination traits of Nyssa yunnanensis is a base to protect this extremely endangered tree species. N. yunnanensis is one of the national protected plants in China. The results of investigations show that three of eight existing trees bear rich fruit but have no regenerated seedlings in natural forests. The study on seed dormancy and germination attempts to unveil key factors causing regeneration failure of N. yunnanensis. It shows that the germination inhibitors existed in different parts of the fruit, particular in seed embryo and pannexterna, are the main factor impacting seed germination. Low water absorption of the seed resulted from obstacle of story endocarp is one of the factors causing seed dormancy. To promote seed germination, the temperature, illumination, and gibberellin acid (GA3) gradient tests were carried out. The results unveil that the optimal temperature for seed germination is 25 ℃. Light is conducive to seed germination because germination rate from light treatment (12 h·d-1) is higher than that from dark treatment. Seed germination percentage, germination vigor and germination index can increase by soaking with 100 500 mg·L-1 GA3, and the best concentration is 200 mg·L-1.

云南蓝果树为中国特有极度濒危一级保护植物，为探讨云南蓝果树濒危机理并进行有效保护，通过野外原位实验和室内受控实验相结合的方法，研究云南蓝果树对种子萌发及幼苗生长是否有自毒效应。结果表明：野外条件下，云南蓝果树的种子萌发受野外枯枝落叶和自身种皮的显著抑制；室内受控实验发现，云南蓝果树的根、茎、叶和种皮浸提液对种子萌发都有不同程度的显著抑制作用，其中，根的抑制作用最强（80.90%），种皮的抑制作用最弱（13.59%），而且云南蓝果树的根、茎、叶浸提液和根际土壤对幼苗生长（株高、叶片数和生物量）也表现出显著的抑制作用。