Study of genetic diversity in T. boeoticum populations under normal and water deficit stress conditions

To study genetic diversity of several agronomic and physiologic traits and the effect of water deficit stress on these characters in 34 populations of T. boeoticum, an experiment was conducted as a split-plot using randomized complete block design with three replications in Research Station of University of Tabriz in 2010. The main plots consisted of stress and non-stress conditions and the populations were considered as sub-plots. Analysis of variance showed significant differences among populations for all studied traits, indicating the existence of genetic variation among populations. Phenotypic coefficients of variation for seed weight and leaf area were highest and for days to physiological maturity were lowest in both stressed and non-stressed conditions. Correlation coefficients and stepwise regression showed significant positive associations of seed weight with leaf area and plant height in both stress and normal conditions. In addition, chlorophyll index was also included in the regression model under normal condition. Cluster analysis grouped populations into five and three clusters in stress and non-stress conditions, respectively. In the water deficit condition, populations 114, 118, 176 and 216 by having the highest chlorophyll index and seed weight had superiority over other populations. In the normal condition, populations 3, 10, 12, 120, 127, 257, 277, 320 and 485 in the second group had the highest seed weight, chlorophyll index and leaf area.