Storage fungi and their deteriorative effects on cumin seeds.

摘要

Eight representative seed samples of cumin collected from major cumin growing regions of Rajasthan at pre- and post-storage stages revealed variations in incidence of seed borne fungi that effect on seed quality and seedling stand. In standard Blotter and Agar Plate tests, Alternaria alternata, Aspergillus flavus, A. niger, Curvularia lunata, Fusarium fusarioides, F. pallidoroseum, Rhizoctonia solani and Rhizopus stolonifer were recorded on incubated seeds. The samples from Bhilwara region had maximum incidence of fungi (76 and 83%), whereas minimum (42 and 48%) were those from Jobner at pre- and post storage stages, respectively as detected by Blotter Method. Incidence of seed borne fungi in seeds were comparatively more (80%) in samples collected at post-storage stage than at pre-storage stage (71%). Seeds with 8% moisture content, stored at 10 C and 60% RH for 6 months showed minimum mycoflora and maximum seed germination. Incidence of seed borne storage fungi at all levels of temperatures was more (13%) at 6 months of storage than at 4 months of storage while some reverse happened in case of field fungi. The volatile oil content in seeds inoculated with A. alternata, A. flavus, C. lunata and F. fusarioides was increased while it decreased in seeds inoculated with A. niger, F. allidoroseum, R. solani and R. stolonifer. Toxic metabolites of all the pathogenic fungi reduced seed germination, root and shoot elongation and seedling vigour.