BIOLISTIC TRANSFORMATION OF ELITE INDICA RICE (ORYZA-SATIVA L.) CULTIVARS THROUGH SEMISOLID AND LIQUID-MEDIUM SELECTION SYSTEMS

Following microprojectile mediated delivery of a plasmid construct (pA HC-25) encoding bar (bialophos resistance) gene into five-day-old scut ellar calli derived from mature embryos, the effectiveness of selectio n procedure for bar-gene expressing tissue was compared for two indica rice cultivars (IR-64 and Karnal Local). While IR-64,transformants co uld, be selected through the generally used semi-solid selection mediu m, the same procedure was not effective in the basmati cultivar Karnal Local. In the latter Case, while lower concentrations (2-4 mg l(-1)) of the selective agent phosphinothricin (PPT) yielded only escapes, hi gher concentrations (6-8 mg l(-1)) inhibited proliferation of transfor med as well as untransformed sectors. For Karnal Local, a liquid mediu m based selection system was successfully utilized for recovering tran sformed sectors and, eventually, regenerants. The study demonstrates t he generation of transformants of two elite indica cultivars using the environment-independent system of mature embryos from seeds.