Culture Optimization And Allied Toxicity Measurement On Bactrocera Dorsalis Of Beauveria Bassiana GIM3.428

In this study, different types of carbon source, nitrogen source and trace element were added to modify the foundation medium, through which to mainly determine the effect of spore germination rate, growth rate spores quantity, and extracellular protease activity. The results showed that adding carbon source could significantly increase the growth of strains GIM3.428. The sucrose had the best effect and the colony growth rate, sporulation quantity and sporulation quantity achieved 1.9mm/d, 16.41×107 spore /cm2 and 114.82 (μ.mg-1Pro.min- 1) separately. Adding nitrogen source to modify foundation medium could significantly improve the growth of strains GIM3.428, the growth rate, the highest sporulation and the extracellular enzyme activity achieved 2.8mm / d, 10.97×107 spores / cm2, 74.67μ.mg-1Pro.min-1 respectively. The best culture medium of GIM3.428 strain was that glucose + yeast extracts + CaCl2 by the orthogonal experiments analysis based the influence of the carbon source, the nitrogen source and the trace element on the spore quantityThe effect of the temperature and irradiation time of ultraviolet radiation on the strain growth was tested. The results showed that during the 19-31℃temperature range the strain germination rate was the highest and achieved 90.3% at 25℃and irradiated 1h, and the germinations rate could achieved 40.9% even irradiated 8h. The rest groups were lower than above. The infection capacity of GIM3.428 to mature larva and Pupa of Bactrocera dorsalis was tested under the conditions of temperature from 19 to 31℃and humidity from 75 to 95%. This test showed that the humidity was the dominant. When humidity was 95% the white muscardine fungi could achieved 62.5% mortality rate of Pupae. The mortality rates of B. dorsalis increased as the temperature increased in the range of 19-25℃and the mortality rates were 50.33%, 46.75% and 28.66% separately at the temperature 25℃,28℃and 31℃.