GROWTH AND PHOTOSYNTHETIC CHARACTERISTICS OF GLYCINE GRACILIS SEEDINGS UNDER DIFFERENT TYPES OF SALINE STRESSES

摘要

Glycine gracilis was used as the experimental material. We tried to explore the difference in growth andphotosynthetic characteristics of G. gracilis seedling under different types of salt stress, and revealed thephysiological stress adaptation mechanisms for semi-wild soybean under salt stress. The results showed thatlow concentration salt stress increased the parameters of growth, but they were inhibited when plants weresubjected to high concentration NS and AS. The inhibition effect of NS and low concentrations of AS on thetotal photosynthetic pigments and chlorophyll contents was not significant, and they promoted the accumulationof carotenoids and chlorophyll a/b. High concentrations of AS significantly inhibited the content of chlorophylland carotenoids and reduced the value of chlorophyll a/b. The daily changes trend and daily means in PN, E, gs,WUE were significantly different under two types of salt stress. PNmax increased at the beginning and thendecreased as AS rose. LCP of G. gracilis was negatively correlated with stress intensity under NS, butpositively correlated with stress intensity for AS. For NS, Resp, Vcmax, Jmax and VTPU increased at first and thendecreased as the salt concentration increasing. However, they gradually declined for AS. Studies haveconfirmed that the range for the inhibition effect on the growth of G. gracilis seedlings were different for thetwo types salt stress. The net photosynthetic rate of G. gracilis also decreased for different reasons. Theseresults also showed that G. gracilis could adapt to the salt stress in certain extent.