Abstract
Experiments were conducted in vitro and in the field for virus elimination and genetic transformation for drought resistance in five varieties of potato. In virus elimination through meristem culture, Cardinal with 1 mg L BAP gave maximum number of shoots (2.43); Dheera without BAP gave maximum number of roots (2.27) explant' and Dheera with 1.5 mg L BAP gave the tallest plantlet (5.23 cm). All the varieties under studies showed 100% virus freeness after DAS-ELISA test. Internode of Cardinal with 4 mg NAA required minimum days (6-8) for callus initiation, 100% explants of both leaf and internode of Heera in 5 mg L1 NAA formed callus and internode of Diamant, Heera and Cardinal with 4, 3 and 5 mg L1 NAA respectively produced 100% compact calli. The best combination for shoot producing calli (26.67%) and the highest number of plantlet callus1 (5.167) was the internode of Diamant with 6.0 mg L' BAP, whereas the tallest plantlet (7.667 cm) was obtained from the internodes of Diamant with 7.0 mg L BAP. The best combination for minimum duration (6-8 days), the highest number of microtubers vial1 (6.00) and the highest average weight of microtubers (152.01 mg) was Diamant with 9% sucrose at 5 mg L BAP. In co-cultivation, the highest callus formation (81.90%) was found in leaf of Diamant with sense; the highest root (40.73%) and shoot (13.33%) forming calli were found in internode of Cardinal with sense and anti-sense gene construct, respectively where minimum days (33) was also required for shooting. Callus derived from internode of Cardinal in anti-sense showed 90% GUS positive response, whereas, stem segment derived from leaf of Heera in sense and from internode of Heera in anti-sense and leaf segment derived from leaf of Diamant and Heera in sense and from internode of Cardinal in anti-sense gave 100% achievement. The transformed plantlets produced bands of expected 760 bp size by the primer whereas non transformed control potato plantlets did not show any band in PCR reaction. In the field adaptation of plantlet, tuber of Cardinal produced the highest number of stems plant (6.73) and the tallest plant (70.93 cm) with white polythene and with water hyacinth respectively. The highest number of tubers plant1 (17.67) was obtained from plantlet of Diamant with water hyacinth and the highest yield plant (805.00 g) from tuber of Cardinal with black polythene. In field performance of microtuber and minituber, tuber of Cardinal produced the highest number of stems plant (5.60) and tuber of Diamant produced the tallest plant (75.87 cm) with white polythene. Minituber of Cardinal produced the highest number of tubers (24.27) and tuber of Cardinal produced the highest yield (597.40 g) plant' with black polythene.