Source Year: 2012

Corynespora cassiicola and Phytophthora meadii, the economically important pathogenic fungi of rubber (Hevea brasiliensis), were preserved with six different storage methods viz. continuous growth method, immersion in sterile distilled water, desiccation on filter paper, desiccation in soil, cryopreservation and lyophilization. Survival was evaluated 1, 3, 6, 9, 12, 18, 24, 36 and 48 months after storage. Immersion in sterile distilled water was found to be the best method for long term storage of both the test fungi with a revival rate of 71 and 62 per cent for C. cassiicola and P. meadii, respectively. C. cassiicola also survived well in cryopreservation and desiccation methods. It was siginficant to note that preservation through continuous culturing eroded the virulence of C. cassiicola over a period of time. In contrast, all other preservation methods sustained post-storage virulence of the pathogen, which is of high value for tissue based germplasm screening against Corynespora leaf disease. Immersion in sterile distilled water was the only method which could support the survival of abnormal leaf fall pathogen P. meadii and preserve its post-storage virulence. Therefore, this method could be used as efficient and cost effective preservation method for both the pathogens under study, without losting their pathogenicity.