Differences In Response Of Dry Pepper To Drought,Salt And Double Stress

Pepper is an important economic crop in Xinjiang,mainly used for pigment extraction and deep processing.However,more than 30% of Xinjiang's land is saline soil,and peppers often suffer from salt damage.In addition to salt stress,dry peppers produced in Xinjiang have less rainfall in summer and autumn,and are also threatened by drought and lack of water.In this study,the two key environmental factors restricting pepper production in Xinjiang,drought and salt,were used as starting points,and dried pepper Honglong 23 was used as the test material to simulate the salt and drought stress environment under potted conditions.The experiment set salt(NaCl)concentration as 0(S0),50 mmol/L(S1),80 mmol/L(S2),120 mmol/L(S3);the relative soil water content was 100%(W0),75%-85%(W1),65%-75%(W2),55%-65%(W3),45%-55%(W4).The effects of drought,salt and double stress on pepper growth and development,physiological and biochemical metabolism,and carotenoid component content were analyzed.The differences in response of pepper to drought,salt and their interaction were systematically clarified to provide high-quality and efficient cultivation of dried pepper Theoretical guidance.The experimental research results are as follows:1.1.The relative water content of the soil is 75%-85%(W1),65%-75%(W2)and its interaction with salt(W1S1),(W1S2),(W2S1),(W2S2)is beneficial to the upper part of the pepper And root growth.The relative water content of the soil is 55%-65%(W3),45%-55%(W4)and its interaction with salt(W3S2),(W3S3),(W4S2),(W4S3)makes the pepper above and below the ground Growth is inhibited.Single salt stress significantly inhibited the growth of the shoots and roots of pepper,and 50 mmol/L NaCl could inhibit the normal growth of peppers.Compared with drought stress,salt stress has more significant inhibitory effect on pepper growth.2.Under single salt(S3),single drought(W2),(W4)and double salt and drought stress(W2S3),(W4S3),pepper antioxidant enzyme activity and free proline content are all increased to alleviate the injury.Under drought stress(W2),pepper oxidoreductase activity and soluble protein content reached the maximum,and pepper drought resistance was further enhanced;under single salt(S3)and double salt and drought stress(W2S3),(W4S3),pepper oxidoreductase activity,Soluble protein content has decreased,and the body's protection system has been irreversibly damaged.3.Single salt(S3)and double stress of salt and drought(W2S3),(W4S3)reduced the chlorophyll content of pepper leaves,photosynthetic capacity decreased,moderate drought(W2)can promote photosynthesis And the inhibitory effect of salt on photosynthesis is significantly greater than drought.4.Single salt(S3)and double salt and drought stress(W2S3),(W4S3)both increase the content of zeaxanthin and other downstream substances in pepper leaves;moderate drought stress(W2)causes ?-carotene and ?-carotene The content of upstream substances increased significantly.And drought stress has more influence on the content of six carotene components of ?-carotene,?-carotene,neoxanthin,violaxanthin,lutein,zeaxanthin than salt stress.