Association of fungi with seeds and more particularly with economically important ones was well known to early seed pathologists. Vigorous efforts to control seed borne pathogens have been made by various workers throughout the world. In some cases suitable control measures were investigated and recommended. The problem of control, however, could not be solved in many cases due to lack of sufficient information regarding the association of fungi with seeds of a particular plant distributed in different localities with diverse environmental conditions. The seed of fungal population is greatly affected by various factors such as aerial spores agricultural operations (viz., harvesting and threshing), transit of seed, method of storage and moisture content of the seed. Sinha and Wallace (1965) and Wallace and Sinha (1962) worked out the ecology of seed mycoflora in Canada. A thorough knowledge of the ecology of seed fungi is a prerequisite before control methods for seed borne fungal disease can be developed. It was therefore, desired to investigate the effect of different ecological conditions of the seed fungi of certain crop plants and using the information obtained to determine the best method of control.
Seed of Bajra (Pennisetum typhoides (Burm f.) Stapf. & Hubb.) collected from four districts, viz., Gorakhpur, Hardoi, kanpur and Unnao of uttar Pradesh, from May to July, 1970 were assayed for the associated seed mycoflora. The seed fungi of samples stored at different temperatures of- 1,8,12,20,25,33,50 and 70°C. To investigate the effect of leaf extracts of Calotropis procera (Ait.) R. Br. and Datura metel Auct. non L., the fresh leaves of the plants were collected. These were washed thoroughly with sterile distilled water (SDW) to remove the phyllosphere microflora. Five hundred g of each plant were mortared separately. The juice was then squeezed, filtered and autoclaved. Various dilutions of the resultant liquid (2,3,4,5,7,8,10,12 and 25%) were prepared in SDW.
Twenty-nine fungal species were isolated from the seeds collected from the four localities. 22,17,18 and 16 species were noticed on Gorakhpur, Hardoi, Unnao and Kanpur respectively. It was noted that higher number of fungal species were obtained from the seed stored between 8-33°C with the maximum at 25°C. The leaf extract of the Calotropis procera and Datura metel tried against seed fungi possessed selective antifungal properties. The Datura extract proved more inhibitory than that of Calotropis. Increase in the extract concentration of both plants decreased the growth of the dominant fungus, Aspergillus flavus in culture. The germination percentage of P. typhoides was also lowered when treated with the culture filtrate of A. flavus. The extract of the two plants were also slightly toxic to P. typhoides at higher concentration.
Cited this as: Kanaujia R.S. and R.R. Mishra (1977): Studies on certain aspects of seed-borne fungi.I. Fungi of Pennisetum typhoides (Burm f.) Stapf. & Hubb. Iranian Journal of Plant Pathology. 13(3-4): 56-66.