Effect Of Exogenous PAs On The Salt-tolerance Of Strawberry

Strawberry, a perennial herbaceous plant, is sensitive to salt-stress. The aggravation of the soil salinization and second salinization limits the development of strawberry. So it is of great importance to study salt-resistance in the growing strawberry and making use of salinization soil.Polyamine, as one of endogenesis signaling component, is ubiquitous in plant organism, it plays a crucial role in regulating growth and development, controlling Morphological architecture, promoting resistance ability, postponing aging action, etc. Polyamine is capable of, as the medium of phytohormone, regulating phytohormone level; removing active oxygen and free radicals from plants, adjusting the osmotic action , maintaining the stability of membrane and enhancing plants' salt-tolerance capability as a result.The field plant of Toyonoka, which is a middling salt-tolerance and widely planted strawberry variety, under different kind and content of polyamine influences was studied in experiment. It can be summarized as following:1. Under NaCl stress, the strawberry's growth was restrained and its chlorophyll content decreased , photosynthesis was damaged, biomass reduced. The application of polyamine can soften the restraining intensity, the treatment of 1×10-5mol/L Put, 1×10-4mol/LSpm and 1×10-3mol/LSpm performed best, at the same time, which could also postpone chlorophyll decomposition, alleviate the injury caused by NaCl, Both the treatment of 1×10-5mol/LPut and Spm were more effective in this respect, but the difference between them was not notable.2. The top of plant was more sensitive to NaCl than root's, the ratio of root/stem went up. Exogenous polyamine could increase the ratio of root/stem under the stress of NaCl, the treatment of 1×10-5mol/LPut,1×10-3mol/L and 1×10-4mol/LSpm, 1×10-4mol/L and 1×10-5mol/LSpd increase the ratio sharply, they were effective in reserving more Na+ in root and refraining it transmission to upside, improving its ability of salt-resistance subsequently.3. The root activity descended under NaCl stress, and it took a trend of descending along with the stressing time accumulated, this phenomenon showed that NaCl stress influenced the growth and function of root and led the plants into bad living. The application of exogenous polyamine could prompt the activity of strawberry root under the NaCl stress. The treatment of 1×10-5mol/LPut, 1×10-3mol/L,1×10-4 mol/LSpm gave a...