The effect of somaclonal variation on salt tolerance and glycoalkaloid content of potato tubers

Salinity has been a major constraint to the growth and production of important crop plants on a global scale. In addition to conventional breeding and the modern genetic engineering approaches, simple and cost effective tissue culture based methods may prove effective to cope with the salt stress induced crop losses. In the present study, we analysed in vitro somaclonal variation on plantlets of potato cv. Desiree and investigated the effect of somaclonal variation on the salt tolerance and tuber glycoalkaloid content. Around 38 regenerated plants were selected from tissue culture-induced calli based on their morphological status. These regenerants were subject to in vitro salt stress evaluation and finally six regenrants were selected based on their salt tolerance performance. Somaclonal variation was confirmed through four RAPD primers. The somaclones and the parental control lines were further evaluated under greenhouse condition for salt tolerance and potato tuber glycoalkaloid content. Out of 38 somaclones, 6 somaclones revealed high salt tolerance evident from maintaning significantly high chlorophyll content. Interestingly, two of the somaclones also exhibited significantly reduced (P < / = 0.05) glycolkaloid content (TGA below 1000 mg/100 g dry weight) compared to that of parental control (180 mg TGA/100 g dry weight) indicating low effect of high salt stress on tuber quality. These results suggest that somaclonal variation may be a useful tool to develop salt tolerance and achieve tuber quality in terms of reduced tuber glycoalkaloid content.