Efficiency evaluation of Bt-transgenic lines of sugar beet against Agrotis segetum Schiff. (Lep., Noctuidae)

Subject Areas : entomology and othea arthropods

L. Sedighi ¹ , M. Rezapanah ² , P. Norouzi ³ , R. Vafaei-Shoushtari ⁴

1 - Entomology Department, Islamic Azad University, Arak, Iran
2 - Biological Control Research Department, Iranian Research Institute of Plant Protection, Tehran, Iran
3 - Sugar Beet Seed Institute (SBSI), Karaj, Iran
4 - Entomology Department, Agricultural faculty, Islamic Azad University, Arak branch, Arak, Iran

Received: 2009-09-17 Accepted : 2010-03-08 Published : 2010-05-22

Keywords:

Abstract :

The common cutworm (Agrotis segetum Schiff.), is one of the most important pests of sugar beet (Beta vulgaris L.), in Iran. Among the alternatives to control this pest, use of B.T.-transgenic sugar beet expressing cry1Ab gene has gained attention due to its efficiency. In the present study, larval mortality, larval weight loss and damage level of this pest on 18 treatments (16 T1 transgenic and 2 non-transgenic sugar beet lines) were evaluated in 3 CRD experiments with 4 replications. Therefore, 40 larvae of the common cutworm in 4 replications (10 larvae/replication) were fed on leaves of the treatment lines in glass Petri dishes. The mortality, weight of larvae and weight loss of leaves were recorded at the third and the sixth days after infestation (DAI). ANOVA results confirmed the significantly differences at %1 probability level among treatments in all of the evaluated factors (except larval mortality at 3 DAI). Finally, mean comparisons were carried out using Duncan’s multiple range tests at %5 probability levels. Based on the results, all of the examined transgenic lines were more effective than non-transgenic lines against A. segetum. The results confirmed that the transgenic line S36-13 (7.5-20% larval mortality, 1.57-10.76 mg LaWL and 39.3-53.64% Leaf Weight Loss at 3 and 6 DAI) was the most effective among evaluated transgenic and non-transgenic lines.