| The experiment was carried out in the rainproof shed of potted plantation base of Shenyang Agricultural University from 2016 to 2017.Used the previous selected droughtresistant peanut varieties Huayu 22,Luhua 11 and the water-sensitive peanut varietiesYuanza9102,Baisha 1016 as materials,drought treatmentand CK were set up.The responses of these peanut varieties to drought stress were studied by measuring morphological traits,photosynthetic characteristics,reactive oxygen,antioxidant enzymes,osmotic regulatory substances,hormone content,yield and related traits.The results were as follows:1.The morphological characters of drought-resistant peanut varieties were less affected by drought stress.Under drought stress,the decrease of total root length,root surface area,leaf area and dry matter accumulation of the drought-resistant varieties Huayu 22 and Luhua 11 was significantly lower than that of Yuanza 9102 and Baisha 1016,althoughthose measuring indexes of Yuanza 9102 and Baisha 1016 were significantly reduced.2.Under drought stress,the chloroplast structureof drought-resistant peanut varieties wasmaintained relativelycomplete.The chloroplast structure of water sensitive peanut varieties was destroyed by drought stress,andthe number of Inner basal lamellar layerwas decreased.The lamellar structure was blurred and the number of addicted to oh corpuscleand starch grains was increased and became larger.The number of cristae in mitochondria was decreased,and the membrane structure was destroyed.These affected the normal function of chloroplast.But the degree of damage of drought stress resistant varieties was smaller than that of water sensitive varieties.3.It was amazing that drought resistance cultivar could maintain better photosynthesis characteristic under drought stress.The decrease of Pn,Tr,Gs and Ci in Huayu22 and Luhua 11 was significantly lower than in Yuanza 9102 and Baisha 1016,but also the recover after re-water was better.The index of ETR was higher than in Yuanza 9102 and Baisha 1016,companied positive correlation with ΦPSII,which showed that PSII system was working normal and insured routine photosynthesis.4.There was lower accumulation of ROS and more activity of autioxidantenzyme activities in drought resistance cultivar.The accumulation of MDA and H2O2 were lower,but the higher enzyme activities of SOD,POD and APX in Huayu22 and Luhua 11,which showed that there was better eliminating ability of ROS in drought resistance cultivars.5.Under drought stress,osmotic adjustment substances was increasingly accumulated.The free proline and soluble protein content was higher in Huayu22 and Luhua 11 than that in Yuanza 9102 and Baisha 1016,which could maintain normal press and integrity of plant cell endowing drought resistance for Huayu22 and Luhua 11.6.Abscisic acid(ABA)is important for peanut drought resistance.Under continuously drought stress,the content of ABA was significantly higher in Huayu22 and Luhua 11 with drought resistance than in Yuanza9102 and Baisha 1016.Meanwhile,there was significant interaction relationship among endogenous hormone.7.Under the drought stress,the number of fruit per plant and the weight of the fruit of drought resistant cultivar were more.Though it was significant that the number of pod,fruit,and the weight of fruit,100-pod and 100-kernel was decreased under drought stress,the number of pod and the weight of fruit was higher in drought resistance cultivar,as well as less decreasing rate of yield per plant and higher drought resistance index. |
