61C-36 |
Grain molding fungi association in food type sorghum kernels and effects on germination |
R. RODRIGUEZ1, R. A. Frederiksen, W. L. Rooney, W. E. H. Omer, I. Kollo, A. Quero, C. N. Aguilar, and M. L. Reyes-Vega. (1) Food Research Department, Universidad Autonoma de Coahuila, P.O. Box 252, Saltillo, Coahuila, 25000, Mexico Grain molding is mentioned as the most important factor related with the loss of grain quality in sorghum. It is caused by a complex of fungal species. A series of experiments was conducted to assess the relationship among grain molding fungi species within each grain mold rating. Seed samples from a field evaluation of 131 F2-derived F5 recombinant inbred families at eight environments were collected to isolate grain mold fungal flora. At each environment grain mold was recorded on a 1 to 5 scale (1=seed bright, free from mold damage; 5=very susceptible, seed embryo and endosperm deteriorated) at 40-45 days after flowering. The most prevalent molding fungi specie isolated was Fusarium moniliforme, which accounted for 46% of the total fungi species recovered. Other species isolated were Alternaria sp. (32%), Curvularia lunata (8%), Fusarium semitectum (7%) and Dreschlera sp. (3%). C. lunata was negatively correlated with Alternaria sp. and Dreschlera sp., and no relation was found between C. lunata and Phoma sorghina . F. moniliforme was negatively related with Alternaria sp and positively related with C. lunata. In this case , the significant correlations between different sorghum grain molding fungi over locations should not be seen as fungal interactions, but rather as the influence of environmental conditions. A positive correlation was observed between the predominance of F. moniliforme and C. lunata with germination. A Spearman rank-order correlation determined negative relationship between seed germination and fungal species diversity. Principal component analysis was used to determine the fungal interactions in each grain mold rating. As grain mold rating decrease, so does fungi interaction complexity. Knowledge about fungal flora present in different grain mold rating scares allows making inferences about the most predominant fungi species, the most important interactions among those species and may help to enhance selection process for resistant varieties.
Session 61C, Food Microbiology: General I
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