Investigating seed priming on some physiological characteristics and yield of three genotypes (Q12, Q29 and Giza1) of quinoa (Chenopodium quinoa willd) under different irrigation regimes.

Introduction: One of the non-biological stresses for crop plants is drought and lack of water, which is the most important factor limiting the growth of crop plants in arid and semi-arid areas, including Iran. Drought impairs normal growth, disturbs water relations, and reduces water use efficiency in plants. Plants, however, have a variety of physiological and biochemical responses at cellular and whole organism levels, making it a more complex phenomenon. The rate of photosynthesis is reduced mainly by stomatal closure, membrane damage, and disturbed activity of various enzymes, especially those involved in ATP synthesis. Plants display a range of mechanisms to withstand drought, such as reduced water loss by increased diffusive resistance, increased water uptake with prolific and deep root systems, and smaller and succulent leaves to reduce transpirational loss. Therefore, the effects of drought stress and seed nutritional priming on plants can play an important role in managing different irrigation regimes to deal with adverse environmental conditions and improve crop yield management. Materials and methods: Quinoa is one of the crops that has received special attention in recent years due to its high nutritional value and resistance to dehydration. For this purpose, an experiment was conducted in the form of a factorial split plot, with three rounds of irrigation of 7, 10 and 14 days as the main factor and seed priming at two levels without prime as a control and Iron sulfate + zinc sulfate combination as the second factor was applied on three genotypes (Q12, Q29 and Giza1) of quinoa as secondary factors, in the crop year of 2021-2022 in the regions of Neishabour and Kashmar. Results and discussion: Moisture stress decreased the relative water content and percentage of membrane stability. In Kashmir region, the highest relative water content was observed in cultivars Q12 and Giza under the treatment of irrigation once every 14 days. While in the Neishabur region, the highest value of the mentioned variable was obtained in the treatment of irrigation once every 7 days and cultivar Q29. Slicing analysis of the interaction effect of cultivar and irrigation treatments and the interaction effect of irrigation and priming in Kashmir region showed that the 7 and 10 day irrigation treatment was significant on cell membrane stability. Comparison of the average interaction effect of the three tested factors in Neishabur area showed that the variety Q12 (regardless of seed priming) along with applying 14 days of irrigation caused a significant increase in membrane stability in Neishabur. Although the lowest level of membrane stability was obtained in the priming treatment of Q12 and Giza cultivars with the application of 7 days of irrigation once. It was observed that the priming treatment of Q29 and Giza cultivars with irrigation every 10 and 7 days, respectively, showed the highest amount of total chlorophyll in the Kashmir region, while in the Neishabur region, the highest amount of total chlorophyll was obtained in non-priming of Giza cultivar with the application of 10 Irrigation once a day. The results of the experiment showed that seed priming of Q12 and Q29 cultivars under irrigation once every 7 days caused a significant increase in seed yield in Kashmir region. In Neishabur region, the highest amount of seed yield was obtained in the non-priming cultivar Giza under irrigation once in 10 days. Conclusion In general, seed priming with zinc sulfate and iron sulfate can improve the physiological characteristics of quinoa under water stress. Although in regarding the relative water content, the Q29 variety had a dominant effect on the priming treatment in Neishabour region. According to the results of the Q29 variety in the Kashmar region and the Giza variety In the Neishabour region, it will help plant growth by maintaining the chlorophyll content of the leaves under low irrigation conditions. [ABSTRACT FROM AUTHOR]