Natural Rubber, Hevea Brasiliensis (Willd. Ex A. Juss.) Müll. Arg., Germplasm Collection In The Amazon Basin, Brazil: A Retrospective

Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg., whose center of diversity is the Amazon basin, is the major source of commercial rubber in the world. In the 1970s, the need for new Hevea germplasm arose from the realization that there was a gradual erosion of the genetic variability of the rubber clones in many natural rubber plantations. This erosion occurred because most of the clones in cultivation were derived from the few surviving seeds collected in 1876 by Henry Wickham. Therefore, to broaden the genetic base of the major producers of natural rubber, it became necessary to undertake an expedition to the Amazon basin to obtain materials for the ‘gene pool’ in these populations. This expedition, called “Germplasm 81,” was organized in four stages. Initially, there was a 1976 seminar organized by the International Rubber Research and Development Board (IRRDB); then, in 1977, a Hevea workshop took place, also organized by the IRRDB. A preliminary mission by IRRDB officials to several countries in South America and the Caribbean followed in 1978. Finally, the Germplasm exercise by scientists from IRRDB countries (Cote d'Ivoire, Indonesia, Malaysia, Nigeria, and Thailand), China, and Brazil took place from January to April of 1981. A ‘dummy run’ to test the viability of seeds from Manaus, Brazil, was undertaken in 1979. The Germplasm collection covered three Brazilian states: Acre, Mato Grosso, and Rondônia. Collection teams traveled into the remotest parts of the Amazon rain forests looking for high-yielding and disease-resistant trees from which to collect seeds, budwood, and seedlings growing around the trees. Three teams collected a total of 64,256 seeds, 1413 meters of budwood, and 1160 seedlings. Following agreements with the Brazilian government, collected seeds were divided on a 50–50 basis between IRRDB and Brazil. Materials for Brazil were retained in Manaus, while those for the IRRDB were initially sent to Britain for phytosanitary treatment and then to Guadeloupe for further quarantine in 1982, before being sent to Asian and African reception centers. Scientists who participated in the exercise had to undergo quarantine in a temperate country for at least one week before returning to their research institutions. This quarantine was an attempt to avoid the spread of the deadly South American leaf blight (SALB) disease. This disease has prevented Brazil from becoming a major world producer of natural rubber, despite attempts made by Goodyear and Firestone Rubber Companies, as well as Henry Ford in the early 1900s.