Effects Of Artificial Flooding On The Growth And Morphological Characteristics Of 15 Tree Species Seedlings

This paper studied the response of 15 species to morphological characteristics, growth, anatomical structure, photosynthesis, hormone under different water stress simulating field experiments, some results were as follows:1. Waterlogging stress caused the height, ground diameter, biomass of the seedling except for Salix babvlonica decline. To a certain extent, waterlogging index and leaf area index reflected the nature of waterlogging tolerance of species.2. By using the paraffin section method, we observed that Salix babvlonica and Taxodium distichum formated the leaves - stems - root cortex road connected the air. cortex of leaves, adventitious roots of underground stems of Sapium sebiferum formated less aerenchyma, and cortex of roots and stems is not observed significant changes. Anatomical structure of Camptothecae acuminata is similar to rice. The way of aerenchyma formation is lysigenous aerenchyma.3. Under waterlogging stress, except that Pn,Gs of the Salix babvlonica were slightly higher than the CK, Pn,Gs of the seedling declined to different degrees. The sharp decline of Pn was result of decline of Gs and photosynthetic capacity.4. There was no siginificant trend regarding changes of hormone content in leaves. Increasing ABA content in leaves inhibited the increase in GA, but it had different effect on IAA content in leaves of different species.5. By the principal component and cluster analysis based on 17 parameters, Parameters such as biomass, seedling height, ground diameter, leaf area index, waterlogging injury index, SOD, ASA-POD, ASA, soluble protein, proline, IAA, GA content was selected for the classification. Fourteen species were divided into most-prevented waterlogging type, prevented waterlogging type, medium-prevented waterlogging type and non-prevented waterlogging type. Fourteen flooding species were ranked as follows: Salix babvlonica > Metasequoia glyptosteoboides > Taxodium distichum > Pterocarya stenoptera > Fraxinus chinensis > Bischofia polycarpa > Populus deltoides > Liquidambar formosana > Sapium sebiferum > Caraya illinoensis > Camptothecae acuminata > Nyssa sinensis > Pistacia chinensis > Ginkgo biloba.