Trans-polyisoprene Content and its Molecular-weight Distribution in Various Cultivars of Eucommia ulmoides

Abstract

We attempted to elucidate the biosynthetic mechanism for trans-polyisoprene and create a transgenic plant with enhanced rubber content. For this, it was important to collect various cultivars having different varieties of trans-polyisoprene. We investigated the trans-polyisoprene content and molecular-weight distribution based on biomass and bark appearance in 24 cultivars collected from the Shaanxi, Hunan, Guizhou, and Sichuan provinces of China. These cultivars were planted in Northwest Agriculture & Forest University in China. The leaves of the 24 cultivars were harvested in Oct. 2004. In conclusion, the average trans-polyisoprene content in the 24 cultivars was approximately 3%-4%; the highest content was over 6%, and the lowest content was below 2%. The molecular-weight distribution showed a bimodal distribution.