Efficacy of Streptomyces sp. Isolate SRF1 to Control the Fungus Pestalotiopsis spp., Causal Agentof MangoLeaf Spot

Abstract

Pestalotiopsis spp. is a causal agent of leaf spot of many fruits and economic crops, especially mango. In addition, this fungal pathogen causes production yield losses. The purpose of this study was to evaluate the antifungal efficacy of Streptomyces sp. SRF1 against 10 isolates of Pestalotiopsis spp. isolated from mango leaf spot disease using dual culture method. The results showed that Streptomyces sp. SRF1 could inhibit the mycelial growth of all tested isolates of Pestalotiopsis spp. in the range 73.37-91.51%. The culture filtrate of Streptomyces sp. SRF1 in AGMS medium containing arginine was also used to determine the antifungal activity by agar well diffusion as say. The results revealed that the culture filtrate from arginine media had antifungal activity. Moreover, the culture filtrates were used to evaluate the inhibition of fungal mycelial growth and spore germination. The results revealed that the culture filtrate also inhibited fungal mycelial growth and spore germination. In addition, abnormal mycelial and short germ tubes of spore were observed when compared with the control treatment. The culture filtrate effectively reduced the size of the disease lesion and disease severity on mango leaf and fruits after inoculation with the plant pathogenic fungi.

Keywords

• mango leaf spot
• pestalotiopsis spp.
• streptomyces sp