| Hainan province, which is located in the tropical areas and belongs to a typical tropical monsoon climate, is a major province of natural rubber production in our country. Natural rubber is important strategic material of national defense and rubber trees have been planted in Hainan for over100years. Hainan island has a relatively complex terrain, which is encircled by the sea, with high mountains in central regions, numerous hills in the south, plateaus and plains in the north. With complicated geographical conditions and perfect climatic conditions, and the fact that typhoons always blow down many rubber trees in July, August and September, wood-rotting fungi like the Ganoderma get sufficient nutritional growth media, and so, abundant fungi resources are accomplished in Hainan’s rubber plantation. The Ganoderma fungi can grow on broken wood and dead stumps of rubber trees and shelter forest. Some species can also invade into roots of rubber trees and cause severe red root disease, and some infect wounded stems to cause butt and root rot disease. Investigating the Ganoderma fungi resources in rubber plantation and working out the pathogen fungi’s species and biological characteristics have important theoretical and practical significance to further develop and utilize useful medicinal and edible fungi, to explore specific species suitable for native planting, to further enhance rubber plantation’s economic benefits, to increase rubber farmers’income, and to effectively prevent and control fungi-caused diseases such as red root disease and butt and root rot disease, etc. Our research made a preliminary investigation of the Ganoderma fungi resources on fallen and dead trees in rubber plantation and windbreaks in Hainan island, and we got the below results.(1) The Ganoderma fungi samples were obtained in rubber trees of18counties and cities in Hainan island. Over180specimen were got in rubber plantation and shelter forest in Danzhou, Wenchang, Chengmai, Wuzhishan, Baisha, Sanya, Dongfang, Lingao, Ding’an, Qiongzhong, Lingshui, etc.(2) Initiatory morphological identification was taken and17species of Ganoderma fungi were separated and identified. They are Ganoderma albornartginatm, G. lobatum, G.annulare, G. luteomarginatum, G. lucidum, G. australe, G. tropicum, G. donkii, G. pseudoferreum, G. gibbosm, G. applanatum, G. philippii, G. brownie, G. capense, G. ungulatum, G. diaoluoshanense and G. resinaceun. Traditionalmorphological taxonomy can distinguish characteristic basidiocarps from others, so we can classify them into specific genus or species. But it’s difficult to identify strains stored in the form of hyphae, or basidiocarps which is underdeveloped. In this case, molecular methods can be adopted to identify strains which are very alike in morphology to the species level.(3) Among the above17fungi species,4species were preliminarily confirmed as pathogens. Ganoderma pseudoferreum and G. philippii are major pathogens of rubber red root disease. G. tropicum and G. capense are important pathogens causing withering of trees and plants in shelter forest such as Acacia confuse, Casuarina equisetifolia Forst., Eucalyptus robusta Smith, etc.(4) Among the17fungi speceies, there are six species which can be used as medicine--G. lobatum, G. luteomarginatum, G. lucidum, G. tropicum, G. gibbosm, G. applanatum. They have potential of further research and development.(5) Elementary biological characteristics of G. gibbosm and G. australe were measured, including growth rate, medium components, temperature conditions, etc. Results show that the two species could grow in the temperature range of20℃-37℃, among which24℃-30℃is the best, so they belong to typical thermophilic fungi species. It makes little difference for the utilization of carbon resources and the most suitable carbon sources are similar. As to the ability to use nitrogen resources like soy peptone, there is no big difference. It’s better for G. australe to utilize beef extracts, ammonium sulfate, ammonium chloride and sodium nitrate than G. gibbosm. No actual disparity is showed to the use of inorganic salts, except that the influence of magnesium sulfate to G. gibbosm is bigger than G. australe. |
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