Fungi associated with seeds of tuba-tuba (Jatropha curcas L.) and their effects on germination seedling stand and quality and quantity of oil

Occurrence of fungal isolates associated on seed of jatropha varies in different locations wherein 56 fungi were detected. Most number of isolates were found in site 2 of South Cotabato (50), followed by 14 isolates in Davao and 11 isolates each from site 1 of South Cotabato, PNOC and 2 sites of General Santos. Thirty-three of the isolates were identified as sporulating of which the genus Aspergillus had the highest % of occurrence (54.54%), followed by Penicillium (18.18%), Fusarium and Lasiodiplodia (6.06%), and 3.03% occurrence each of Chaetomium, Nigrospora, Alternaria, Cladosporium and Peyronellaea. Non-sporulating fungi comprised 23. Isolates that grew faster on selective media were utilized to determine the effects on seeds and seedlings of Jatropha. They were coded as Aspergillus sp. CRO1, CRO7, CRO12, CRO13, Penicillium sp. CRO21, Fusarium sp. CRO11, Peyronellaea sp. CRO14, Nigrospora sp. CRO30, and Cladesporium sp. CRO33. Significant reduction in germination was observed to those seeds infected with Penicillium sp. CRO21, Aspergillus sp. CRO12 and Sp. CRO13 with 40%, 20%, and 26% germination, respectively, as compared to 70% germination of control. These isolates also caused reduction in seedling height, with values of 9.45 cm, 3.0 cm and 5.79 cm, respectively, as compared to an average height of 21.41 cm, respectively, in contrast to an average length of 5.33 cm of control. Those results indicate that a significant reduction in viability of seeds also caused significant decrease on plant height and root length of Jatropha. Fungi that were associated frequently and have significant effect on seedling stand, Aspergillus sp. CRO1, sp. CRO7, sp. CRO12, sp. CRO13, Fusarium sp. CRO11 and Penicillium sp. CRO21, were utilized to determine the effect of moldiness on yield of oil and profile of oil (using biosoft quantiscan) stored at different storage time at 95 to 100% relative humidity. Aspergillus sp. CRO7 significantly lowered yield of oil about 30.14% reductions as fungal invasions and storage time lengthened. Moreover, change of color from natural yellow to darker color was observed in oil extracted from inoculated and uninoculated seeds. Profiles of glyceride species varies among the isolates infecting seeds at different storage period. Isolate of Penicillium sp. CRO21 infecting seeds showed the highest increase in % of FFA [free fatty acids] of extracted oil from 2.83% to 18-98% as storage period increases.