The effect of different concentrations of salicylic acid on germination characteristics of two genotypes of quinoa ( Chenopodium quinoa willd.) under salinity stress

Due to the development of saline lands and reduction of favorable agricultural land for cultivation identification of salinity-resistant medicinal plants, or factors that can reduce the effect of salinity are of high importance. Salinity is one of the major environmental limiting factors on plant growth and productivity. Seed priming is used to improve seedling establishment and increase plant efficiency. Priming is a simple technique that improves seedling establishment and improves the efficiency plant in the field. In fact, the main effect of seed priming is on the rapid growth of seedlings and early germination. Salicylic acid plays an important role against abiotic stresses such as salinity due to the high protective power of the plant. Find plants that are tolerant as a suitable way for the efficiency of salt water and limited water resources in the country. Selection of Quinoa as a like Grain is one of the best ways to prevent crop yield loss under stress conditions. Quinoa is a grain-like plant with high nutritional value and tolerance to abiotic stresses such as heat, cold and drought stress. Quinoa is resistant to drought and salinity due to its phenological flexibility and resistance to climate constraints. Food quinoa importance due to the perfect combination of amino acids, calcium, phosphorus, iron and sodium low. The flour from this plant lacks gluten and is a good food for people with small intestine autoimmunity. It also prevents cancer, cardiovascular disease and osteoporosis with high phytoestrogens.

Thus, in order to investigate the effect of Salicylic acid pre-treatment on germination indices of quinoa seedling under salinity stress, a factorial experiment was conducted based on completely randomized design with three replications in Seed Technology Laboratory, Faculty of Agricultural Sciences, Shahed University in 2019..The experimental factors included; salicylic acid at four levels (0, 0/5, 1 and 1/5 Mm) and salinity stress caused by NaCl at four levels (0, 50, 100, 150 mM NaCl) and the quinoa cultivars were Giza1 and Titicaca. Measured traits included germination percentage (GP), mean germination time (MGT), germination rate (GR) and germination coefficient (GC), SVI: seedling longitudinal index, SVI: seedling weight index and pigment content Are photosynthetic. Statistical analysis of data including analysis of variance was performed using SAS 9.1 software and mean comparison of traits evaluated by LSD test at 5% level of probability.

The results showed that increasing the salinity stress decreased the content of photosynthetic pigments and seed germination characteristics.under salinity stress, with increasing stress, the germination percentage decreased so that the lowest germination percentage was observed at salinity stress of 15 dS/m. Application of salicylic acid under salinity stress had a positive trend in germination percentage, so that at different salinity levels, application of 1 mM salicylic acid showed the greatest effect on germination percentage. and at concentrations below 1 mM this trend was reduced. The Longitudinal index of seedling vigor and weight indices of seedling vigor were observed at 1 mM salicylic acid concentration and no salinity stress. with the concentration of salicylic acid increased, the content of photosynthetic pigments showed an increasing trend. Based on these results, proper plant management can guarantee plant establishment under salinity stress. Based on these results, by applying seed priming with salicylic acid, plant establishment can be improved in salinity stress conditions.