A high throughput bioassay system for screening of Bt transgenic plants expressing Cry proteins

In the present study a rapid screening technique was developed to identify transgenic progenies that are resistant to a target pest at seedling stage under greenhouse conditions. Seedlings of 10 day-old insect resistant transgenic cotton and 30 day-old brinjal were used for bioassay. Two and four days after the release of neonate larvae in cotton and brinjal, respectively, seedling bioassay could distinguish susceptible plants from the resistant ones. The seedling bioassay procedure can give a rapid and early assessment of insect resistance, significantly reducing the time required for validation of genes of interest. This bioassay has potential as a rapid method for screening transgenic cotton and brinjal for insect resistance as well as evaluating the effects of insecticidal proteins on the larvae.