| High oleic acid peanuts refer to peanuts with oleic acid content accounting for 75%or more of the total fatty acids.It has the characteristics of strong antioxidant capacity,high nutritional value and storage resistance.High oleic acid peanut is more and more favored by consumers because of its outstanding advantages.Recently,China’s peanut production is experiencing a new round of variety renewal marked by high oleic acid varieties replacing ordinary oleic acid varieties,and high oleic acid peanuts have also become a research hotspot in recent years.In this study,two common peanut varieties and eight high oleic acid peanut varieties were used as experimental materials.Two methods of indoor hydroponics and field experiments were used to explore the physiological characteristics of high oleic acid peanut under drought stress(0%PEG-6000,10%PEG-6000),salt stress(0mmol/L,200mmol/L),temperature(Sowing on April 9th,April 26th,May 7th,May 15th,June 1st,June 15th.),and the differences in nutrient content,yield and quality between common peanut and high oleic acid peanut.The purpose of this study was to analyze the changes of physiological indexes and growth indexes of high oleic acid peanut under drought,salt and temperature,and to provide a theoretical basis for the cultivation of high oleic acid peanut in arid and saline areas and the timely sowing of high oleic acid peanut.The main results are as follows:1.Under PEG simulated drought stress,the drought resistance coefficient and root morphological characteristics of high oleic acid peanut were higher than those of ordinary peanut.The root length,root surface area,root volume,root tip number,root activity,shoot dry weight,root dry weight and total dry weight of peanut decreased under drought stress,and the root shoot ratio increased.Except that the root activity of high oleic peanut in small grain group decreased more than that of ordinary peanut,the other indexes of high oleic peanut decreased less than that of ordinary peanut.Under PEG simulated drought stress,the SOD and POD activity of high oleic acid peanut leaves increased less than that of ordinary peanut,the CAT activity of high oleic acid peanut in large grain group increased less than that of ordinary peanut,and the CAT activity of high oleic acid peanut in small grain group increased more than that of ordinary peanut.There was no significant difference in MDA content between high oleic acid peanut and ordinary peanut.There was no significant correlation between drought resistance and high oleic acid.there are high oleic acid varieties with better drought resistance than ordinary peanut.Huayu 9111,Huayu 9113,Shanhua 21,Kainong 308and Jihua 11 had better drought resistance.2.Under salt stress,the relative values of biomass salt tolerance coefficient and root morphological characteristics of high oleic acid peanut were lower than those of ordinary peanut.Salt stress reduced the root length,root surface area,root volume,root tip number,root activity,shoot dry weight,root dry weight and total dry weight of peanut,and increased the root shoot ratio.The decrease of root activity of high oleic peanut was less than that of ordinary peanut,and the decrease of other indexes was greater than that of ordinary peanut.Under salt stress,the increase of SOD activity in leaves of high oleic acid peanut was less than that of common peanut,the increase of POD activity and MDA content was greater than that of common peanut,and the decrease of CAT activity was greater than that of common peanut.In the small grain group,the increase of SOD and POD activity of high oleic acid peanut was greater than that of ordinary peanut,the decrease of CAT activity was less than that of ordinary peanut,and the increase of MDA content was less than that of ordinary peanut.There was no significant correlation between salt tolerance and high oleic acid.there are high oleic acid varieties with better salt tolerance than ordinary peanuts.The salt tolerance of Jihua 19 was higher than that of ordinary peanut,and the salt tolerance of Shanhua 21 and Kainong 308 was higher than that of other high oleic acid varieties.3.With the increase of temperature,the time required for peanut emergence becomes shorter and the total accumulated temperature required decreases.When peanut germination and emergence experience low temperature conditions,the emergence rate will decrease.The decrease of Shanhua 20,Shanhua 9 and Shanhua 21 planted with film mulching is less than that of Shanhua 21 planted in open field.The seedling emergence rate of’Yunshanhua 20’and’Shanhua 9’was not affected after April 26,and the seedling emergence rate of’Shanhua21’was not affected after May 7.The SOD,POD,CAT activity and MDA content of peanut increased when it experienced low temperature at seedling stage,which improved the ability of seedlings to resist low temperature stress.With the delay of sowing date,the daily average temperature of seedling stage increased,and the enzyme activity decreased first and then increased.Low temperature will reduce the yield of peanut.The degree of reduction of Shanhua 20,Shanhua 9 and Shanhua 21 in film mulching cultivation is less than that in open field cultivation.Shanhua 21 in open field cultivation is significantly lower than that in film mulching cultivation by 26.8%.The yield of peanut was the highest at the suitable temperature,that is,Shanhua 20 had the highest yield of 4234.12 kg/hm~2at 23.73℃(April26th),Shanhua 9 had the highest yield of 4957.67 kg/hm~2at 23.6℃(April 26th),Shanhua21 had the highest yield of 4574.07 kg/hm~2at 24.32℃(May 7th),Shanhua 21(open field)had the highest yield of 4489.94 kg/hm~2at 24.63℃(June 1st).Shanhua No.20 is suitable for film mulching sowing at 23.73℃(April 26th).Shanhua No.9 is suitable for sowing at23.6～24.27℃(April 26th to May 7th).Shanhua No.21 is suitable for film mulching sowing at 24.32℃(May 7th)and open field sowing at 24.57～24.63℃(May 15th to June 1st).4.The overall change trend of dry matter accumulation,nitrogen,phosphorus and potassium nutrient content and accumulation in various organs of high oleic acid peanut was consistent with that of ordinary peanut during the whole growth period,but the accumulation of nitrogen and phosphorus per plant of high oleic acid peanut was higher than that of ordinary peanut,nitrogen utilization efficiency and phosphorus demand were higher than that of ordinary peanut,nitrogen demand and phosphorus utilization efficiency were lower than that of ordinary peanut. |
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