Determination of germination characteritics of alfalfa(Medicago sativa L.) seeds covered with microbial preparation underdroughtand salinity stress conditions

ABSTRACT DETERMINATION OF GERMINATION CHARACTERISTICS OF ALFALFA (MEDICAGO SATIVA L.) SEEDS COVERED WITHMICROBIAL PREPARATION UNDERDROUGHT AND SALINITY STRESS CONDITIONS Teslime BIÇAKCI MSc Thesis in Department of Field Crops Supervisor: Assoc. Prof. Dr. Mehmet ARSLAN June 2019;70 pages This study aimed to improve the germination of alfalfa seeds, which are sensitive to environmental conditions during germination and early seedling development. Seeds of the Nimet registered to Eastern Mediterrane an Agricultural Research Institute alfalfa variety that had not been treated after harvest were coated with Panoramix and germinated under salinity stress conditions. Panoramix was applied in three concentrations; zero (control), 2 liters/1000 kg of seeds and 4 liters/1000 kg of seeds. A laboratory germination experiment was laid out in a randomized parcel design using sealed petri dishes with four repetitions and two factors. Salinity stress was applied at zero, 25, 50, 75, 100, 150, 200 and 250 mM NaCl. Six different drought stress levels (0, -2, -4, -6, -8 ve -9.8 bar) were handled in this study and were used Polyethylene glycol-6000 (PEG-6000) to create of drought stress at different levels. 50 seeds was laid in each petri dish and placed in germination cabinet (70% humidity, 20 °C temperature 14 hours light (2000 lux) 10 hours darkness). A greenhouse emergence test was performed using plastic pots filled with a mixture of 50% soil + 50% sand. Irrigation water containing dif-ferent salt concentrations (zero, 75, 150 and 250 mM NaCl) was applied to the pots. Four different drought stresses [0 (T0), %25 (T1), %50 (T2), %75 (T3)] were applied to the pots. At the end of the both experiments, germination rate was calculated and the fresh and dry weight of the shoots and roots, length of shoots and roots were determined. With the increase in the severity of drought stress, the germination, emergence and early seedling growth characteristics of alfalfa seeds were decreased. The results indicated that the coating treatmens positive contributied to the germination properties of alfalfa seeds under drought stress conditions.