Laticifer Differentiation In Adult Rubber Tree And It's Application To Rubber Yield Prediction

We investigated the laticifer differentiation in Hevea brasiliensis Mull.Arg. clone RY7-33-97 and the application of laticifer differentiation on the rubber yield prediction by experimental morphological strategy and some of cytological and molecular techniques, and obtained the following results:①Under natural conditions, virgin rubber trees initiated laticifer differentiation from June to July with a high frequency of newly-formed laticifers from August to October whereas no laticifer differentiation occurred from November to the May next year.②Exploitation could induce laticifer differentiation on large scale in tapped trees.③Exogenous jasmonates could induce the laticifer differentiation in both tapped trees and virgin trees.④Expression of genes encoding for the key enzymes for rubber biosynthesis was upregulated markedly by both exploitation and exogenous jasmonates. A high level expression of the genes by exogenous jasmonates sustained much longer than that by exploitation.⑤There was an obviously different in laticifer differentiation upon wounding in the wild rubber tree germplasm population. The difference in laticifer differentiation upon wounding was closely related to the ability of adult rubber trees to differentiate laticifers and to produce rubber.The results provided a theoretical basis for developing techniques to regulate laticifer differentiation in the practice of natural rubber production, and meanwhile, a candidate physiological parameter for predicting rubber yield.