Complementary Evaluation of Safflower Germplasm of National Plant Gene-Bank of Iran for Drought Stress Tolerance

Drought stress is the main limiting factor in growth and development of crops, including safflower (Carthamus tinctorius L.) in drought and semi drought regions of world. This project conducted to evaluate effects of water deficient in quantity and quality characters of autumnal safflower germplasm in laboratory and field conditions. In laboratory, in a factorial experience in randomized complete block design, with three replications in four osmotic potential levels (0, -0.4, -0/8 and -1.2 mp) by poly ethylene glycol 6000, the germination characters were evaluated. In the field, physiologic and agronomic cheracters of genotypes evaluated in a randomized complete block experience design, with three replications in two conditions, normal and water stress in 50 percentage of heading stage. Results showed germination percentage and shot let length reduced by reduction of water potential. But the length of root let incseased till -0.4 mp and decreased in lower potential. In the field water stress had a significance reduction effect in 100 weight grains, head weight, yield, biomass, days to maturity, number of grain in a head, length and width of bracket and but oil percentage increased in water stress condition. The most yields belonged to genotype number 15 and 14 respectively in normal and stress conditions and the lowest yield belonged to genotype number 11 in both conditions. The most result, from the perspective of gene bank was the existence of variety of genotypes reactions to drought stress. The tolerance and sensitive index showed that some of genotypes same number 15 had high yield in normal condition but low in stress condition while genotype number 7 that had lower yield relative 15 genotype in normal condition, had higher yield relative 15 number in stress condition. Since the breeding for drought tolerance in genotypes with high production potential in dry and wet years is the target, the accession number 7 has this ability. With a little negligible for a bit less yield in normal condition, the genotype number 14 has a similar situation of genotype number 7. Named vriety involves sensitive accessions same number two that has less yield in stress condition. And there are accessions that have intermediate behavior. Accession number 14 reacted less sensitive to drought, therefore this acsession and accession number 7 are suitable for breeding in drought and number 15 for normal conditions.