关键词: 棉花, 盐分胁迫, 根系形态, 生理特性

Abstract: In order to discuss the impact of salt stress on photosynthesis and nutrient uptake of different cotton varieties at seedling stage and providing a theoretical basis for cotton cultivation management, salt tolerance mechanism and saline land improvement, this paper took salt sensitive cultivar (CCRI45) and salt tolerant cultivar (CCRI35) as materials, and conducted pot experiments to investigate the effect of salt stress on cotton photosynthesis character and nutrient adsorption. Results showed that salt stress significantly decreased the dry matter accumulation of cotton root, stem, leaf, whole plant and photosynthesis characteristic. Compared with the CK, the dry matter weight of whole cotton plant, net photosynthetic rate, stomatal conductance and transpiration rate decreased by 39.1%~40.1%, 33.9%~41.1%, 34.3%~36.6% and 27.7%~28.8%, respectively. The decreasing range of salt tolerant varieties was smaller than that of the salt sensitive varieties. The salt stress also significantly inhibited the adsorption and accumulation of N, K and P nutrients, and reduced the content of chlorophyll SPAD in cotton leaves. The decrease of net photosynthetic rate under salt stress was caused by no-stomatal restriction. Photosynthetic parameters and nutrient uptake were closely correlated with the resistance of genotype.

Key words: cotton, salt stress, root morphology, physiological property