assessment of the genetic variation and drought tolerance among genotypes

this experiment was conducted to evaluate the drought tolerance of cultivated (carthamus tinctorius l.) and wild safflower (c. oxyacanthus bieb) populations at research farm of college of agriculture, isfahan university of technology located at lavark-najafabad in 2008. a randomized complete block design with 3 replications was used in each of irrigation levels after 80, 130 and 180 mm evaporation from class a pan, respectively. evaluation of genetic variation revealed a significant difference among cultivated and wild safflower genotypes for agro-morphological traits. for example wild safflower had significantly higher value for the number of heads per plant indicating that it can be used for improvement of cultivated species through intraspecies hybridization. moisture stress also had a significant effect on all studied traits. clear differences existed between the two species (cultivated and wild) for moisture stress tolerance with the wild species being more tolerant than the cultivated one. increasing water stress level caused significant reduction in the seed yield of cultivated genotypes whereas the wild genotypes were not affected as much. results indicated that wild safflower has a general stability under moisture stress which is useful source for improvement of drought tolerance in cultivated safflower.