Rapid Rhizometric Screening and Selection of Upland Rice Landraces for Drought Tolerance

In line with a progressive plant breeding program, the current study attempted to identify prospective parent materials for drought tolerance breeding using rhizometric and morphometric variables. Twelve upland rice genotypes (URLs) as subplots were subjected to 0, 5, 10, 15 and 20-days duration of water withdrawal (DWW) as main plots in a Split-plot experiment of a modified adaptation of the PVC Tube method in RCBD. The. ANOVA revealed that DWW affected drought sensitivity-leaf rolling and drought recovery score. Drought susceptibility index determined that Rinara was tolerant, and the rest were found to be highly tolerant. Principal Component Analysis (PCA) revealed that 84.34% of the variation observed in this experiment can be accounted by three principal components. Standardized Shannon-Weaver Diversity Index (H’) of URLs under 20 days DWW ranged from H’=0.71 to H’=0.98 and were highly diverse (H’=0.83) confirming PCA results. Pearson Product-Moment Correlation showed that maximum root length had medium positive linear relationship with plant height (r = 0.63**) whereas root surface area was highly correlated with network length (r = 0.91**) and volume (r = 0.93**).