The Effect Of Waterlogging On The Growth, Physiological And Biochemical Of Three Tree Species

With the completely randomized experiment design, the outdoor bonsai soil culture experiment was conducted to study the influence of waterlogging on the one-year-old seedlings which is Taxodium distichum, Sapium sebiferum and Carya illinoensis from the aspects of the growth, photosynthetic characteristics, chlorophyll fluorescence, expression of specific proteins, porosity and radial oxygen loss under waterlogging treatment. The research result has a great significance to reveal the Waterlogging mechanism, enrich tree waterlogging theories and select waterlogging tree species. The main results were as follows:1) Waterlogging treatments inhibited the biomass growth of the three species markedly (except the mild waterlogging treatment of Taxodium distichum), but the number of adventitious roots increased significantly. To judge from the relative growth of the three species, T. distichum showed the strongest waterlogging tolerance, followed by S. sebiferum and then C. illinoensis.2) Waterlogging treatments significantly reduced net photosynthetic rate (Pn), Stomatal conductance (Gs) and Chla fluorescence maximum quantum efficiency (Fv/Fm) of the three tree species. The higher the degree of waterlogging is, the greater they decrease.3) Waterlogging stress significantly increased porosity of root, stem and leaf of the three tree species. The porosity in root of T.distichum, S.sebiferum and C. illinoensis had increased by 4.0%～15.0%,3.2%～8.3% and 0.4%～3.0%, and 0.3%～9.6%,1.8%～9.3%,14.0%～17.7% in stem, and 1.2%～7.7%,0.4%～4.3%, 0.4%～3.0% in leaf, respectively. The higher the degree of waterlogging is, the greater the porosity increases. The porosity in the three tree species shows an up trend when the waterlogging time increases.4) Waterlogging treatments significantly increased radial oxygen loss of T. distichum and S. sebiferum and it was consistent with the porosity. The degree of waterlogging treatment could also affected the level of root radial oxygen loss. Radial oxygen loss of T. distichum was flooding treatment> waterlogging treatment> mild waterlogging treatment.5) Based on the establishment of a set of electrophoresis system suitable for the three tree species, leaf protein expression patterns were studied through SDS-PAGE and dimensional electrophoresis. There were 37 waterlogging stress-specific protein spots and 41 specific waterlogging stress-up-regulate protein spots in the 201 different spots, and there were 38 waterlogging stress-specific protein spots and 36 specific waterlogging stress-up-regulate protein spots in the 223 different spots which were matched with the four treatments of analysis system of T. distichum and S. sebiferum respectively.6) Through comprehensive comparative analysis, it shows that tree waterlogging is closely linked to the number of adventitious roots, porosity and radial oxygen loss and the expression of specific proteins.