Investigation the Drought Tollerance of Sesame (Sesamium indicum L.) Local Landraces Based on Drought Stress Tolerance Indices in Different Levels of Irrigation and Mycorrhizae

Sesame is one of the plants that due to the high content (47-52%) and high quality (low cholesterol and some antioxidants) its seed oil, important role has in human health. An experimental with objective to evaluate eight local landraces of sesame to drought stress based on grain yield and drought tolerance indices using factorial split plot design was conducted with three replications in research field of Urmia agricultural high school. The main factor was consisted different levels of irrigation, normal irrigation (irrigation after 70 mm evaporation of crop (ETc)), moderate drought stress (irrigation after 90 mm ETc) and severe drought stress (irrigation after 110 mm ETc), sub plots including two kinds of mycorrhizae fungi Glomus mosseae, Glomus intraradices and non-inoculated (control). Sub-sub plots consisted of eight local landraces of sesame with names Jiroft13, Zanjan Tarom landrace, Moghan landrace, Naz of several branches, TC-25, TS-3, Darab 14 and Dashtestan 5. Ten drought tolerance indices including mean productivity (MP), geometric mean productivity (GMP), stress tolerance index (STI), harmonic mean (HARM), yield index (YI), drought resistance index (DI), stress non-stress production index (SNPI), modified stress tolerance index in optimum irrigation (MPSTI) and modified stress tolerance index in moderate and severe stress (MSSTI) were calculated based on grain yield under well-watered (YP), moderate drought stress (YS-mild) and severe drought stress (YS-severe) conditions. Based on cluster analysis, the studied local landraces were grouped in 3 clusters in each one of water treatment conditions. Based on biplot analysis, local landraces Moghan landrace and Zanjan Tarom landrace as resistant genotypes and landrace TC-25 were classified as moderately resistant and other local landraces were somewhat susceptible.