study of drought stress effect on fruit and essential oil yield of different genotypes of coriander as medicinal plant

using medicinal plants as drug or spice in food have significantly increased in recent decades. also, production of this plants restricted by drought stress. therefor the aim of this was investigation of drought stress effect on fruit and essential oil yield of different endemic coriander genotypes. in this regard, 14 coriander genotypes subjected to two levels of water treatments in two separate experiments of normal irrigation and water stress through randomized complete block design with three replications. this experiment was done in research farm of etka organization at varamin in 2014. results showed that drought stress had significant effect on fruit and essential oil yield and percent of brock fruits. the difference between genotypes were significant for these features. also, significant genotype × stress interaction effect shows that some of genotypes had different response to the water treatments.  the 357 genotype had the highest fruit yield in both normal irrigation and drought stress and genotype 230 had the highest essential oil yield in both normal irrigation and drought stress. mp, gmp, tol and sti indices which are indicator of drought tolerance were gained by 357 and 230 genotypes. further, ssi index which is indicator of drought susceptibility had high value for 158, 306 and 450 genotypes. in overall, 357 introduced as suitable genotype which had appropriate yield and drought tolerance.