برسی اثر متابولیت های ثانویه باکتری Bacillus subtilis موتانت M419 علیه بید کلم( Plutella Xylostella )

Today, the importance of food and produce is not covered by anyone,taking into consideration that food supply security is one of the prioritise in our country, fight agricultural pests and plant diseases is of great importance. Plutella xylostella is the most serious pest of Brassicaceae family in the country.
The Brassicaceae family has 10 tribes, 350 genera and about 400 species. The most important plants of this family are the types of cabbage, the most important member of this family is Brassica oleracea (Cabbage). The larval stage of Plutella xylostella, foods from cabbage leaves and results damage. In this study the effect of Bacillus subtilis, mutant M419 of this bacterium, on 1-2 and 3-4 larval instars have been investigated. LC50 value of M419 on 1-2 larval instars in one, two and three days after contact were 4343/449, 2993/1620, 2607/124 μg/ml and on 3-4 larval instars have been equal to 10429/007, 7366/478, 6149/872 μg/ml respectively. The results showed that there is no significant difference on mortality rate, 3 days after contact, between the two types of bacteria, also LT50 for M419 on 1-2 larval instars, at the doses of 1500, 1850, 2300, 2850, 3000 μg/ml were 11/057, 7/386, 4/237, 4/006, 1/581 days respectively. Furthermore the value of LT50 M419 on 3-4 larval instars at the doses of 3500, 4500, 6000, 7500, 9500 μg/ml have been equal to 20/481, 4/794, 4/041, 2/488, 1/143 days respectively. LC50 values increased with increasing larval instars indicating more resistance in higher larval instars. Also the days needed to cause 50% mortality in 1-2 and 3-4 larval instars decreased with increasing doses.