seed germination behavior of lentil genotypes (lens culinaris medik) under temperature and drought stress regimes

rapid germination is an important factor determining the final yield. the most important abiotic stress threatening lentils is drought and temperature. therefore, this study was performed with the aim of investigating effects various thermal treatments (5, 10, 15, 20, 25 and 30°c) and four levels of drought (0, -4, -8, -12 and -16 bar) on percentage and germination rate of lentil genotypes. a split plot factorial experiment based on completely randomized design with three replications was conducted. number of germinated seeds was recorded daily and percentage and germination rate was calculated. there was no germination on -8, -12 and -16 bar, hence these levels were ignored. the results showed that temperature, drought stress and their interactions had a significant influence on final germination percentage and rate of lentil genotypes. the percentage and germination rate in genotypes of lentil declined in low and high temperature treatments. the germination percentage and speed of all genotypes also declined in drought stress than favorable conditions. in fact, drought stress causes that physiological and metabolic processes of germination be impressed and reduce in their speed. overall, mean and optimum temperature range for germination of genotypes, were estimated at 15-20c in both stress and no-stress conditions.