Effects Of Water Stress And Rewatering On Yield And Physiological Characteristics Of Oats In Different Periods

Oatmeal is a high-quality grain-feeding crop with many advantages,such as high grass yield,good quality,drought tolerance,tolerance to barrenness and so on.As an emerging high-nutrition crop,oats planting area gradually increased in the northeast region.In recent years,water resources in the northeastern region are scarce.Oats often suffer from water deficits,improper rehydration period or uneven re-watering during the growth and development process,their yield and quality are seriously affected.Therefore,this paper explores the effects of drought stress and rewatering on the yield and physiological characteristics of oats in various growth stages of oats,and provides a theoretical basis for improving the water use of crops.The experiment was carried out in the form of potted plants in the western part of Jilin Province.Water stress and rehydration treatment of two spike-type for oats were carried out in the tillering stage,jointing stage and flowering stage,to investigate the effects of water treatment on the growth and yield of oats,and screen out drought-resistant oat varieties.The main results of this study are as follows:?1?Rehydration after tillage,jointing,and flowering water stress reduced the grain seed yield of two spike-type oats.Re-watering after jointing water stress at jointing and flowering stage significantly reduced grain seed yield of two spike-type oats comparison of oats under no stress conditions.And the severity of heavy water stress during flowering is greater.However,the water stress and re-watering in the tillering stage were smaller,and the difference was not significant.Therefore,oats are more tolerant to drought stress in the tillering stage,and late yield is less affected by drought stress in the tillering stage.The flowering period is the key period for the formation of oats,and sufficient water should be maintained during the actual cultivation process.In addition,compared with the spike-type Sweet oats,the grain yield of loose spike-type oats Linne was less affected by drought stress.Therefore,in order to ensure the grain yield of oats,the dry area can choose to plant loose spike-type oats Linne.?2?Re-watering after tillage,jointing,and flowering water stress reduced the grain weight per panicle,effective panicle number and 1000-grain weight of two spike-type oats.Among them,severe water stress decreased the most during flowering.This paper finds that grain seed yield is significantly positively correlated with these agronomic traits.This indicates that the water stress during flowering period leads to a decrease in the number of firming spikelets of oats,a decrease in the quality of the thousand grains,and a dryness of the grains,which in turn causes a decrease in yield.?3?Drought stress at tillering stage,jointing stage and flowering stage significantly decreased net photosynthetic rate,intercellular CO₂ concentration,stomatal conductance and transpiration rate of two panicle types oat leaves,there is a certain compensation after rehydration,however,these parameters are still lower than those of the leaves without stress.The photosynthesis parameters of loose spike-type oats forests decreased more,and the?¹³C values of stems and leaves were lower than that of tight spike-type sweet oats.And after suffering from drought stress,the dry matter of Sweet oats accumulates in the stems and leaves,the amount of substances transferred to the panicles decreases,and the distribution rate of panicles decreases more.Therefore,comparing the two spike-type of oats,Linne has a greater degree of response to water,and has strong drought resistance and high yield advantages.?4?Under water stress,the water use efficiency of two spike-type of oat decreased,and the compensation effect was obtained after the stress was removed in the tillering and jointing stages and rehydrated,the rehydration oats at jointing stage showed super compensation effect.It can be seen that the jointing stage is a period in which oats are more sensitive to moisture.In actual production,timely water replenishment after deficit irrigation in jointing stage can improve the water use efficiency of crops,thereby saving water resources.?5?The water stress and rewatering at different growth stages affected the morphological characteristics of oats.Water stress and rewatering reduced the plant height and leaf area of two spike-type of oats.Although there was a certain compensation effect after rehydration,it was still lower than the non-stress state.The plant had better compensation for plant height after rewatering in the tillering stage,and the water stress had a greater influence on the leaf area of the loose spike-type.?6?The water stress at each growth stage decreased the protein content of the two spike-type oat kernels,and the water stress and re-watering decreased at the tillering stage is the greatest.The water stress at different growth stages reduced the starch content of the two spike-type oat grains,and the water stress had a greater influence on the starch content of the Sweet oat grains.In addition,water stress had a greater effect on the soluble sugar content of Sweet oats.