Evaluation of germination and vigor parameters of rapeseed parents seeds resulted from the heat and drought stress at the end of growth season

In order to investigate germination parameters, two separated experiments were done as a factorial form with completely randomized design including heat experiment (factors were planting date and cultivars) and drought experiment (factors were levels of stress and cultivars) with three replications. Germination parameters experiments maternity seeds including germination percentage, seedling, plumule rootlet length, seedling, plumule and rootlet dry matter weight, alometric index and seed vigor. Results showed that drought and heat stress has reduced seed weight at %5 probability level and has led to produce wrinkled and low weight seeds. Average germination percentage due to drought and heat stress were reduced 23% and 48%, respectively. Length and dry matter seedling which is a scale of mother seed vigor significantly reduced by drought and heat stress effect. Seedling length of the seeds which were obtained of planting date November11 compared to planting date Januray10 was reduced from 14.2 to 5.9 centimeter that equaled 59%. Drought stress reduced maternity seeds vigor form 14.1 to 9.01 that equaled 36% and heat stress reduced maternity seeds vigor form 13.45 to2.75 that equaled 80% and it showed that seed vigor decreased more due to by heat stress. Heat and drought stress because of reducing maternity matter storage in seed by lowering seed weight led to reduced plumule and rootlet growth, and finally quality of produced seeds. Hence, with management these two stress we can improve the quality and production of rapeseed and yield.