In vitro morphophysiological screening of drought-tolerant potato genotypes

Sixteen potato genotypes were assessed for drought tolerance through morphophysiological characteristics using stress tolerance trait index (STTI), principal component analysis (PCA), and cluster analysis (CA). Two to three wk old nodal segments explants (1.0 to 2.0 cm long) derived from in vitro grown sprouts were cultured on MS medium that contained with different concentrations of sorbitol. After 6 wk of culture initiation, the length of shoots, roots, and internodes; thickness of shoot and roots; number of leaves and roots; fresh and dry weight of whole plant; and water content of plants were recorded. For PCA, the cultivars Arun, Granola, Surjomukhi, Sheelbilati, Jamalu, Chollisha, Patnai, and Dohazari showed relatively higher values regarding drought tolerance and Diamant, Asterix, Courage, Cardinal, Lalpakri, Sindurkouta, Ausha, and Sadaguti were drought-sensitive cultivars. For cluster analysis, the cultivars Arun, Granola, and Surjomukhi showed high tolerances to drought and Diamant was sensitive. Analysis of variance (ANOVA), Duncan's multiple range test (DMRT), and correlation coefficient for different morphological and physiological traits showed significantly higher values at p < 0.01 level among the tested genotypes. The protocols standardized under this study may be helpful for plant breeders and biotechnologist to develop mass production of potato seeds/tubers in drought-prone areas.