Development of Fruit and Shoot Borer Tolerant BrinjaL

INTRODUCTION

Brinjal has been cultivated in the country for the last 4,000 years, although it is often thought of as a Mediterranean or mid-Eastern vegetable. Among the Solanaceous vegetables, brinjal, Solanum melongena Linn. is the most common, popular and principal vegetable crop grown in many geographical parts in India. The area under brinjal cultivation is estimated at 0.51 million ha. with total production of 8,200,000 Mt (FAO data, 2005, http://faostat.fao.org/). Brinjal is mainly cultivated on small family farms and it is a source of cash income for resource-poor farmers. This staple vegetable crop is extensively damaged by the insect brinjal fruit and shoot borer (Leucinodes orbonalis) and losses range from 50-70%. The young larvae of the pest bore in to petioles and midribs of large leaves and tender shoots causing shoot tips to wilt and later they bore in to flower buds and fruits. The affected fruits loose their market value besides considerable reduction in yield.   The pest poses a serious problem because of its high reproductive potential, rapid turnover of generations and intensive cultivation of brinjal both in wet and dry seasons of the year. Farmers use large quantities of chemical insecticides singly or in combination to get blemish free fruits, which fetch premium prices in the market. Around 25 to 80 sprays are undertaken for effective control of brinjal fruit and shoot borer. This practice of indiscriminate use of insecticides leads to build up of pesticide residues in the produce, destruction of beneficial ionsects, pest resurgence,  pesticide exposure to farm workers and environmental pollution. To reduce pest-linked damage in brinjal crop as well as to protect the environment from adverse effects of pesticides, deploying the lepidopteran specific cry1Ac gene under the control of enhanced CaMV 35S promoter for high level expression in brinjal would provide an effective built-in control for brinjal fruit and shoot borer as a insect resistance management strategy. This would result in bringing down the cultivation costs of brinjal, as contribution of chemical pesticides to brinjal cultivation is sizable.

Bt brinjal being a transgenic food crop, requires environmental clearance under Rules 8, 9, 10 & 11 of the Rules and Procedures notified by the Ministry of Environment and Forests vide Notification no. 1037 (E) dated 05.12.1989. Prior to the deregulation of transgenic fruit and shoot borer tolerant brinjal data and information is necessary to be produced to demonstrate that this Bt brinjal is equivalent to currently grown non-Bt brinjal varieties in composition and agronomic performance and that the Bt protein expressed by the inserted gene causes no adverse effect when consumed by domestic or wild animals and beneficial insects. The bio-safety and environmental issues related to the Bt brinjal were assessed, which includes molecular characterization of induced gene, biochemical characterization of the expressed protein, estimation of the level of the expressed insect control proteins in brinjal and brinjal products, safety of the expressed proteins to non-target organisms, environmental fate of the Bt protein, and agronomic, compositional and food and feed safety evaluation of Bt brinjal compared to non-Bt brinjal.