| چکیده انگلیسی مقاله |
Extended abstract Introduction:Pepper (Capsicum annum L.), which belong to the family solananceae, is one of the most important vegetable and garden products, that because of the nutritional value, the tendency to use it, is increasing all over the world. Germination and seed emergence are strongly influenced by environmental stresses such as salinity and drought. Drought stress affects the various aspects of plant growth and reduces germination and vegetative growth and reduces dry matter in plant.Salinity stress is one of the most extensive environmental stresses and is a limiting factor for the growth and development of crops, and garden production. Materials and Methods:The present study was conducted to evaluate the impact of drought and salinity stresses on seed germination characteristics of sweet pepper (Capsicum annuum L.) in two separate experiments, using a completely randomized design with three replications in Faculty of Agriculture, University of Birjand in 2016. Drought stress was applied by PEG 6000 and salinity stress was used with NaCl.Treatments included drought and salinity stresses levels (0, -2, -4, -6, -8, -10 and -12 bars). Seeds were washed with sodium hypochlorite (2%) solution for 1 minute disinfection and then washed with distilled water. The medium was petri dishes with a diameter of 9 cm and in each, 25 seeds were placed on two layers of filter paper, then, was added to each petri dish, 5 ml of distilled distilled water or solution.The measured traits were germination percent, germination rate, seed vigor index, radicle length, plumule length, ratio of radicle length to plumule length and dry weight of radical and plumule. Results:The results indicated that salinity and drought stresses had significant effects on seed germination characteristics of sweet pepper, so that,salinity stress with osmotic potential of -10 and -12 bar decreased germination of sweet pepper and reached to zero. Increasing salinity stress from zero to -12 bar decreased germination percent, germination rate, and seedling dry weight by 43.75, 41.67 and 93.46%, respectively. Results indicated that with increasing both salinity and drought stresses, seed vigor index decreased significantly. The result showed that with increasing drought and salinity stress from 0 to -12 bar, seed vigor index was decreased 96.58 and 100 percent, respectively. Conclusions:The results of this study showed that the tolerance to salinity stress of the sweet pepper in the germination stage was higher than that of drought stress, but for more accurate evaluation, it is necessary to conduct additional experiments in the field and in the greenhouse. Highlights: 1- Study and compare of germination and seedling growth of sweet peppers under salinity and drought stress. 2-Salinity and drought stress reduced germination indicators of Capsicum annuum. |