EFFICACY OF Candida melibiosica FOR CONTROL OF POST-HARVEST FUNGAL DISEASES OF CARROT (Daucus carota L.)

Abstract

Biological control using antagonistic yeast has emerged as one of the most promising alternatives in postharvest protection of fruit and vegetables. The aim of the present studies was to investigate the potential of the yeast Candida melibiosica for biocontrol of Botrytis cinerea, Alternaria alternata and A. radicina, fungi pathogenic to carrot roots, and explain the possible mode of action of this antagonistic microorganism. The ability of the yeast to inhibit fungal growth in vitro, produce volatile compounds and lytic enzymes, and protect infected carrot roots was studied. C. melibiosica inhibited the growth of B. cinerea on potato-dextrose agar and malt agar by 25.9% and 33.3%, respectively, but only slightly restricted the growth of A. radicina and had no effect on A. alternata. The volatile compounds acting against B. cinerea and A. radicina were produced by C. melibiosica growing on malt agar. The yeast produced -glucanase and chitinase with activities between 34.0–232.86 U · cm-3 and 20.74–43.7 U · cm-3, respectively. Application of the yeast to carrot roots before inoculation with the fungi B. cinerea and A. radicina reduced the progress of the disease

Keywords

• biocontrol
• antagonistic yeast
• phytopathogenic fungi