Abstract:
Objective Antifungal activity of the isoflavones of Ormosia hosiei on Botrytis cinerea Pers was investigated for the development of a natural disease control agent on tomato plants.
Methods Inhibitory effect of the isoflavones extract from seeds of O. hosiei on the pathogen, B. cinerea, that infects tomato plants was tested according to the in vitro fungal growth rate. Functions of the isoflavone monomer biochanin A on the changes of mycelial dry weight, cell membrane, reducing sugar content, and activities of catalase, peroxidase, superoxide dismutase, and other protective enzymes of B. cinerea were analyzed. Physiological, biochemical, and bacteriostatic effects of the monomer on tomatoes were observed in vitro.
Results Biochanin A of O. hosiei significantly inhibited the growth of B. cinerea with an EC50 of 203.189 μg·mL−1. Its presence lowered the dry mycelia weight, cell membrane permeability, and reducing sugar content but rose the protective enzyme activities in hyphae of B. cinerea.
Conclusions The ethyl acetate extract from the seeds of O. hosiei was rich in alkaloids and flavonoids. Of which, isoflavones was believed to be the key active antibacterial components that inhibited the fungal growth by interfering the growth, impairing the cell membrane functions, and reducing the protective enzyme activities of the hyphae.