Rubber yield is limited by two intrinsic limiting factors: the latex flow limited by coagulation processes, and the laticifer metabolic potential to regenerate the lost latex between to lappings. Another limiting factor consists in the sensitivity of trees to Tapping Panel dryness (TPD), a desease which can be induced by overexploitation. All these limiting factors has been proven to depend on culivars, hence should be genetically deterntined. As any other cell, the latex cells enclose, wrong the other common organelles, nuclei, which are involved in the control of the cell life and perforntance. One of the objectives of the Thai-French "Hevea Biotechnology- Project" is to design, through both a "specific" and "blind" approach, new molecular tools to be used in a latex molecular diagnosis alluwing adapted recnmmendations for optimal exploitation of the various rubber cultivars, as well as for assisted selection in the rubber breeding programs. The other objective is to clone and characterize laticifer specific and/or stress inducible promotors to design specific gene constructs to be used in the future genetic engineering of the rubber tree.