INTRODUCTION OF RICE CHITINASE GENE IN POTATO BY AGROBACTERIUM-MEDIATED TRANSFORMATION

Abstract

Potato is an important food crop of the world. Different viral, bacterial and fungal pathogens cause heavy economic losses of this crop every year. Potato has complex genetic makeup due to which induction of disease resistance through conventional breeding is difficult. Genetic manipulation through different transformation techniques is more precise and successful tool. In the present study different factors were investigated, which have an influence on potato transformation. The optimal dose of cefotaxime was found 500 mg/l which did not affected the growth of the potato tissues. The explants treated with Agrobacterium in the presence of acetosyringone resulted in higher frequency of transformation as compared to the explant without it. Two minutes time for co infection was found appropriate for optimum transformation efficiency. The two days cocultivation period along with 7 days preselection was found suitable for potato transformation. The putative tranformants regenerated on MS medium supplemented with 20 mg/L hygromycine and 500 mg/L cefotaxime, from nodal explants while the non-transformed tissue turned brown and gradually died after two or three sub culturing on the selection media containing selective antibiotic hygromycin. The shoots obtained on selection media shifted on root induction media supplemented with similar concentrations of hygromycin and cefotaxime, resulted complete plantlet formation after 10 days. It was observed that all the hygromycin positive plants also exhibited positive bands of desired size of 823 bp for chitinase gene, suggesting cotransformation of both genes in transformed plants