Screening and identification Streptomyces spp. of Lam Dong Province which can suppress root rot Pythium vexans fungus in cruciferous vegetables

Abstract

Pythium vexans fungus is one of the major causes of root rot and reduces crop growth. Currently, research on the application of biological products in controlling and preventing harmful fungus is increasingly concerned with the strategy of developing clean and sustainable agriculture. Many Actinomycetes species of the genus Streptomyces are considered safe for humans as well as plants, capable of inhibiting the growth of many plant pathogenic fungi by secreting a number of bioactive compounds. In this study, from 15 soil samples of vegetable gardens in Lam Dong province, 20 strains of Streptomyces spp. were isolated. Of 20 isolates, the strain Streptomyces LD5.4 was rated with the highest inhibitory effect on the fungus, which can suppress root rot Pythium vexans fungus in cruciferous vegetables, reached 51.80%, after 48 hours by disc diffusion method on Potato Dextrose Agar (PDA) environment at room temperature. Based on morphological characteristics and 16S rRNA sequence, Streptomyces sp. LD5.4 was determined to belong to the species Streptomyces filamentosus. With these properties, strain Streptomyces filamentosus LD5.4 has the potential to be used in the production of probiotics against root rot in Cruciferous vegetables, which is caused by Pythium vexans.

Keywords

• hoạt chất sinh học
• pythium vexans
• streptomyces
• streptomyces filamentosus
• thối rễ