Predication of Cardinal Temperatures and Thermal Time Requirement for Seed Germination of Chickpea Genotypes (Cicer arietinum L.) in Drought Stress Condition A .Ganjeali and M. Parsa Ferdowsi University of Mashhad, Mashhad- IRAN E-mail: ganjeali@ferdowsi.um.ac.ir Information about seed germination response of chickpea to temperature and drought stress is Important. The main objectives of this experiment were predicting of cardinal temperatures, physiological days and thermal time requirement for seed germination in chickpea. To this, a split plot factorial experiment based on completely randomized design with 6 chickpea genotypes (MCC361, MCC951, MCC180, MCC873, MCC13 and MCC463) and a range of temperatures (3, 5, 10, 15, 20, 25, 30 and 35 C ) and drought stress levels(0 and -4bar) with three replications was conducted. The percentage of seeds germinated was recorded daily, and germination rate (1/D50) was calculated based on inversing the time taken to reach to 50% cumulative germination. To quantify the response of germination rate to temperature and to determine cardinal temperatures, physiological days and thermal time requirement for germination, Dent-like model was applied. Temperature, drought stress (- 4 bar) and their interactions, had significant influences on final germination percentage and germination rate of chickpea genotypes (P0.001). Overall, mean and optimum temperature range for germination, were estimated 20-26 C, and it was the same in stress and non stress condition. Base temperature were estimated 4.5 and 4.2 (genotypes mean) for stress and non stress condition respectively. There were significant differences among genotypes for physiological days and thermal time requirement for germination, only in stress condition. Drought stress increased thermal time requirement for germination 2.8 times compared to non stress.

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