Background: Drought is the most important factor limiting the production of crops such as sunflower in the world and Iran.
Aim: To investigate the effect of drought stress on some morphological, phenological and phytochemical traits of sunflower cultivars, an experiment was conducted in 2017 in the laboratory and research farm of the Faculty of Agriculture and Natural Resources of Persian Gulf University
Methodology: In this experiment, 11 sunflower seed cultivars (Master, Azargol, Barzegar, Lacoma, Gabor, Progres, Record, Zaria, Farrokh, Armacirsci and Qasem) were studied. Laboratory studies were performed as factorial experiments in a randomized complete block design. The studied treatments included four moisture levels (zero, -1, -3 and -5 atmosphere) with three replications. Measurements were performed on germination percentage and speed, vigor index, fresh and dry length and weight of shoot and root.
Conclusions: The results of analysis of variance showed that the interaction between cultivar and stress levels was significant for all traits at the level of one percent. The results of mean comparison also showed considerable variation in terms of studied traits among cultivars. According to the results of principal component analysis, among the traits studied in the germination experiment, the first three components explained a total of 85.73% of the changes in traits measured on the studied sunflower cultivars. The results of cluster analysis of cultivars for germination traits were able to divide the studied cultivars into 3 groups based on the similarity of the values of different lines. Field studies were conducted in a randomized complete block design with three replications in two wet environments (normal and drought stress). Simple analysis of variance of the data of all three environments showed that the studied cultivars have significant differences in terms of most traits. The results of combined analysis of three media showed that there is a significa