Simple and economical assay systems for evaluation of phosphinothricin resistant transgenics of sorghum, Sorghum bicolor. (L.) Moench., and pearl millet, Pennisetum glaucum (L.) R. Br.

Five simple and rapid methods for evaluation of sorghum and pearl millet transgenics resistant to herbicide phosphinothricin (used as selectable marker) were studied. For rapid in vitro selection, three assays (establishment of sensitivity curves for embryogenic calli, determination of lethal doses for seed germination, and a rapid screening of cut young leaves based on the colour change of the medium) were established. For rapid screening of transgenic progeny, effects of in vivo Basta leaf spray and dip tests were studied at three different morphological stages. For all the above assays, LD50, and LD100 values were higher for pearl millet than sorghum. However, in both the crops, genotype effect was not significant. The assays standardized in the study were found to be effective for rapid, economical and mass-scale identification and characterization of transgenic plants of sorghum and pearl millet.