Effect of antagonistic bacterium Bacillus subtilis B006 as seed coating for control of Botryosphaeria rhodina, cause of gummosis disease in cucurbit

Abstract

The study was conducted to test find out the efficiency of the antagonistic bacterium Bacillus subtilisB006 against to Botryosphaeria rhodina cause of gummosis disease of cucurbit. The bacterium was determined its inhibition capability on the growth of B. rhodina 14 isolates. The results revealed that the antagonistic capability was significantly different into 9 groups. This bacterium was cultured in nutrient broth (NB) added 2% glucose and incubated at 28°C for 3, 5, 7 and 9 days and then, treated at 80°C for 30 min for heat tolerance cells. The maximum heat tolerant cells production (46-47%) was obtained 5-7 days of incubation. Hence the antagonistic bacterium B006 was cultured on such medium and temperature for 5 days and used to incorporate into four seed coating formula-tions; BS-coat1, BS-coat2, BS-coat3 and BS-coat4. The viability and antagonistic activity of the bacterium B006, and its effect on seed performance after storage at 5°C for 4 months were determined. The result showed the number of viable cells varied statistically were significant difference among the formulations ranging from 7-105 cfu/seed. The bacterium B006 obtained from seed wash of each formulation could inhibit growth of B. rhodina as same as the original isolate. No adverse effect on seed germination and seedling performance was observed.