Chitosan and yeast elicitor in suppressing seed-borne fungi of cucurbitaceous vegetables

Experiments were conducted under laboratory condition to examine the efficacy of Chitosan and Yeast Elicitor to suppress the growth of seed-borne fungi of cucurbitaceous vegetables. Seeds of bottle gourd, sweet gourd, snake gourd, wax gourd and cucumber were collected from seed traders of Mymensingh districts and different seed borne fungi were isolated, purified and identified. Fourteen fungal species belonging to twelve genera consisting of Aspergillus flavus, Aspergillus niger, Botrytis cinerea, Fusarium moniliforme, Fusarium oxysporum, Phoma exigua, Rhizopus stolonifer, Macrophomina phaseolina, Penicillium spp., Curvularia lunata, Chaetomium spp., Colletotrichum spp., Cercospora spp. and Alternaria alternata were isolated and identified. Four concentrations of Chitosan and Yeast Elicitors solutions (200, 500, 1000 & 2000 ppm) including one positive control Vitavax-200 WP (0.35%) were evaluated for controlling seed-borne fungi. Among the seed treating agents Chitosan (2000 ppm) and Yeast Elicitor (2000 ppm) showed better performance in suppressing the seed-borne fungi. Chitosan (2000 ppm) showed superior performance than Yeast Elicitor (2000 ppm). Results from the present study revealed that application of elicitors as seed treatment is a potential alternative of chemical fungicide for selective vegetables.J. Bangladesh Agril. Univ. 16(2): 187-192, August 2018

Effect of Abiotic and Biotic Elicitors on Growth and Alkaloid Accumulation of Lycoris chinensis Seedlings

Three-month-old seedlings of Lycoris chinensis were treated with biotic and abiotic elicitors: yeast elicitor (YE), methyl jasmonate (MJ), salicylic acid (SA), and sodium nitroprusside as NO donator (NO). We have shown that the addition of MJ and NO promotes the accumulation of galanthamine in these seedlings. The effect of these elicitors on the growth of the seedlings, as well as on the amount of the alkaloids accumulated in the seedlings was studied. The results showed that, in general, high doses of MJ and SA had a negative effect on the growth of the seedlings, while appropriate doses of NO and YE had a positive effect on the growth of the seedlings. It was remarkable that the addition of MJ, NO, and YE can promote galanthamine accumulation in seedlings. The accumulation was higher in treatments at higher concentrations of NO (100 μM), where the release of galanthamine was 1.72-fold higher than that of the control at the 10th day of culture. The highest values of lycorine were obtained in seedlings treated with YE at a concentration of 0.01 g/l and by the 10th day of culture; the level was 1.38 times of the control.