Isolation and selection of some fungi inhibiting Corticium salmonicolor which causes pink diseases on rubber trees

Abstract

Rubber (Havea brasiliensis Muell.Arg.) is one of the most important industrial plants of Vietnam. However, the expansion of rubber plantation in Vietnam is difficult because of diseases on rubber trees. Pink disease, caused by Corticium salmonicolor, is a common disease on rubber. From 20 soil samples collected in rubber plantation and natural areas, 65 fungi and 288 actinomycetes were isolated. The antagonistic ability with Corticium salmonicolor of 65 fungi varied greatly according to the follow-up period. Among the isolated ones, CT14G1 and PT15G9 were antagonistic 100% with Corticium salmonicolor after 7 days of culture, and PC4G8 was antagonistic 78% with Corticium salmonicolor after 28 days of culture. Based on the characteristics of colonies and characteristics under microscope; based on classifications of Robert A. Samson (1984) and Bergey’s Manual of Determinative bacteriology-9 (1994), PC4G8 is Aspergillus sp.; CT14G1 is Trichoderma sp.; and PC15G9 is Kibdelosporangium sp. (actinomycetes). The combination of PT15G9 + CT14G1 + PC4G8 inhibited strongest the growth of Corticium salmonicolor on cutting branch of rubber trees.