Development of fruit and shoot borer resistant transgenic brinjal with Cry1Aabc gene: An assessment of factors influencing transformation efficiency

Abstract

Brinjal is popular vegetable crop grown in the tropics and subtropics. Fruit and shoot borer (FSB) Leucinode orbonalis is most serious and destructive pest causing heavy yield losses. Agrobacterium mediated genetic transformation was performed in two brinjal cultivars viz RHRB-35 and Manjarigota with Cry1Aabc gene. Several factors influencing transformation efficiency such as type of explants, Agrobacterium cell density, infection time, pre-culture duration, co-cultivation duration, overgrowth control antibiotics have been evaluated. Combination of cefotaxime and carbenicillin at 250 mg/l concentration effectively control Agrobacterium overgrowth. Two week old Cotyledon and three week old hypocotyls explants precultured for 2 days and then infected with Agrobacterium suspension (OD600= 0.2 to 0.4) for 1 min showed maximum transformation efficiency. Among the two brinjal cultivars, RHRB-35 exhibited maximum transformation efficiency (8.44 %). The transgene integration into putatively transformed brinjal eggplant genome was confirmed by PCR analysis using gene specific primers.