consequences of this phenomena which should be placed high emphasis on. Lately, breeders are starting to take a fresh look at using root as a mean to increased plant yield in stress prone regio so much so that, root is now known as a medium to second green revolution. After lots of evaluations and researches, CIMMYT institute has nominated a collection made up of 293 lines of heat drought resilient spring wheat known as WAMI collection in order to use in genome wide association mapping projects with the aim of genetic mapping of related traits with resistance to these abiotic stresses. The objective of this study was to evaluate root traits of 50 genotypes of this collection with 10 Persian lines of spring wheat (2 groups of susceptible and durable lines) under drought condition which has gone under taken in two separate experiments. First experiment was accomplished by cultivating in soil tubes during 2014-2015 and the second one was done during 2015 in a hydroponic environment. Genotypes were assessed in 2 levels of moisture regimes (control and stress) according to a factorial experiment based on a randomized complete block design with 2 and 4 replications for the first and second experiment respectively. In tube experiment observing traits were a series of root traits and also a series of agro-morphologic traits measured on shoot. Since root traits were measured in 0-45 cm and 45-90 cm depth of soil, total amount of listed traits in both depth and the ratio of listed traits in first horizon to second horizon were also estimated. Observing traits in hydroponic experiment were a set of root traits in addition to shoot dry weight.The result of range and phenotypic coefficient of variation in both experiments showed that the range of traits variation among genotypes is quite high for almost all traits. In the tube experiments the results of analysis of variance showed that drought stress has significantly affected all of morphological traits except spike length, also it has affected all the root traits in depth of 0-45 cm and 45-90 cm except average root diameter and network length respectively. In addition, it has not affected total root diameter in both depths and the ratio of all traits in fist horizon to second one. There were no difference among genotypes except for total network volume, surface area and length of the roots in both depths and total biomass, as well. The interaction between stress and genotype was not significant for all traits except total network volume and surface area of roots. But the results of interaction slicing by genotype announced that genotypes number 56, 142, 212, 259 263 have different reactions in each moisture regime and genotypes number 19, 21, 44, 103, 115, 118,138, 192, 216, Gonbad, Sepahan Tajan were considered stable in both moisture regimes. The results of analysis of variance in hydroponic experiment revealed the fact that stress has significantly affected all the root traits. Genotypes were totally different according to all the traits except root and shoot dry weight and network bushiness, as well. The interaction of genotype and drought stress was just significant for network depth, network aria, network surface aria and network volume of the roots. The results of interaction analysis by genotype, designated genotypes number 22, 58, 120, 125, 155, 202, Golestan Moghan as genotypes with different reactions in two moisture regimes and genotypes number 44, 56, 64, 142, 180 Pishtaz were considered stable in both conditions. The results of cluster analysis in tube experiment divided all the genotypes into 7 and 6 groups in control and stress condition respectively and in the hydroponic experiment these results divided genotypes into 7 and 5 groups for control and stress condition respectively. The results of analysis of principal components in tube experiments for both moisture regimes showed that first component had a high and positive correlation with traits in depth of 0-45 cm like root dry weight, network aria, network surface aria and network volume and with total amounts of root dry weight, network surface aria, network volume and network length, as well. Because of these, first component was called root genesis potential. Second component had a high and positive correlation with the ratio of traits like root dry weight, network volume, network surface aria and network length in depth of 0-45 cm to 45-90 cm. so it was called potential of longitudinal development. Third component had a high and positive correlation with traits like shoot dry weight, height, number of spike, spike length and total weight of plant biomass. Because of these, third component was called growth potential of plant. All 3 components integrally consisted 68.34 and 69.98 percent of total variance in control and stress condition respectively. In hydroponic experiment the results of this analysis showed that first component, ...