Rubber Tree Cultivation and Improvement: Laticifer Ring Count and Latex Yield Assessment of Rubber Species

Abstract— Rubber trees (Hevea spp.), the wilderness trees originating from rain forests of the Amazon, have been domesticated outside South America for more than a century. The trees, specifically of the species Hevea brasiliensis, are now widely established in the tropics especially in Southeast Asia. Nevertheless, opportunities to improve the latex yield productivity of these cultivated rubber trees are limited by their narrow genetic base since they have been descended from a small selection of seedlings derived from seeds collected in the 1800’s. Commercial rubber trees hence face this genetic vulnerability of inbreeding depression that could hamper progress in crop improvement. To explore the feasibility of broadening the genetic base, various Hevea species, viz. Hevea brasiliensis, Hevea benthamiana, Hevea camargoana, Hevea guianensis, Hevea nitida, Hevea pauciflora, Hevea rigidifolia and Hevea spruceana, were assessed for their possible contribution to the genetic improvement of the cultivated rubber trees particularly in latex yield output. The assessment showed that Hevea benthamiana, and Hevea spruceana to be promising in terms of the number of laticifer rings in the bark and latex yield. They are promising candidates for incorporation into the improvement programmes of the rubber tree in Malaysia