Abstract
Dearth of water resources and fluctuating climatic conditions severely affect crop yields. In order to explore genetic diversity
underlying drought tolerance, 200 genotypes of bread wheat (Triticum aestivum L.) were phenotyped over two seasons
(2009-10 and 2010-11). Analysis of variance showed significant variation in morphological and physiological traits: days to
heading (DTH), peduncle length (PL), extrusion length (EL), awn length (AL), plant height (PH), leaf rolling (LR), waxiness
(WAX), relative water content (RWC), proline (PRO), thousand grain weight (TGW), grains per spike (GR/SP) and yield
(Y) under normal and drought conditions over both years. Using multivariate analysis, two data sets C&S (control and
stressed) and C-S/C (relative performance) were prepared to examine plant responses to drought. The first principle
component (PC) accounted for 24.97% variation for the 2009-10 and 43.85% variation for the 2010-11 in the C&S dataset.
For C-S/C dataset, 18.12% and 15.58% variation was observed in 2009-10 and 2010-11, respectively. The biplot based on
relative performance data set showed a maximum variation for plant developmental and yield traits except GR/SP and the
number of days to heading. TGW and yield vectors remained close on the biplot showing a significant association.
Association among different traits identified in this study will enrich the repertoire to excel breeding programs like selection
and hybridization.
