Study some of Wheat Cultivars Based on Morphological Traits and Drought Tolerance Indices

Basically, the most important limiting factor in plant growth is the lack of water. More lands in Iran are located in arid and semi-arid region and so identifying of ghenotype that can produce acceptable yield under drought conditions is essential. In order to identification of drought stress tolerant varieties, 20 wheat cultivars were evaluated at three stress levels (control, -0.6 and -1.2 MPa) and in aquaculture medium as a factorial experiment based on completely randomized block design with three replications in the green house of Mohaghegh Ardabili University based on root length, root and shoot fresh weight, root and shoot dry weight and root/shoot dry weight ratio. Stress levels were induced by using polyethylene glycol 6000. Results of ANOVA showed that the stress levels had significant effect on all traits. Also, Cultivars had significant differeces in all traits. The cultivars×stress interaction was significant in all studied traits. The drought tolerance indices of HARM, GMP, MP and STI were calculated based on yield in control (Yp) and stress levels (Ys). Results of ANOVA for indices showed significant difference between cultivars that showed different response of cultivars to drought stress. Comparisons of means were carried out by Duncan's method at one percent probability level. In all of traits the means of cultivars reduced by increasing of stress levels. According to cluster analysis results based on morphological traits in control level, the cultivars of Arta, BC Roshan, Tajan, Gascozen and shiroodi were beter than other cultivars. In -0.6 MPa stress level, the Arta, Shiriidi, Tajan, Kavir and Gascozen cultivars wre tolerant and Moghan2, Rasul and Mihan had partial tolerant to drought stress. In -1.2 MPa stress level, the Kavir, Rasul, Mihan were tolerant to stress. Totally, according to cluster analysis based on morphological traits and tolerance indices, the Rasul and Mihan cultivars were identified as tolerant cultivars.