MADRAS AGRICULTURAL JOURNAL

Efficacy of cry2AX1 Gene in Transgenic Tomato Plants against Helicoverpa armigera and Spodoptera litura

Abstract

      Tomato crop is infested by large number of insect pests, causing significant yield loss. Fruit borer (Helicoverpa armigera) feeds on fruits which leads to quality detoriation and economic loss. Genetic engineering is recognised as a viable tool to engineer resistance in crops against insect pests. Transgenic tomato plants over-expressing cry2AX1 gene under the control of CaMV35S promoter were developed. The T0 and T1 plants were characterized by PCR for the presence and segregation of transgenes. Segregation of cry2AX1 gene in T1 progeny plants followed the Mendelian pattern of monogenic inheritance of 3:1 ratio. The expression of Cry2AX1 at 55 days after sowing ranged from 0.034 to 0.219 μg/g of fresh leaf tissue and 0.030 to 0.249 μg/g of fresh leaf tissue at 80 days after sowing. Insect bioassay of detached leaf bits performed on the ELISA positive transgenic tomato plants against Helicoverpa armigera and Spodoptera litura resulted in mortality of neonates upto 100 per cent in H. armigera and 53 per cent in S. litura.
Key Words: cry2AX1, Transgenic tomato, Insect resistance, Fruit borer