Study On The Effects Of Physiological And Biochemical Characteristics Of Sapium Discolor And Sapium Sebiferum Under Waterlogging Stress

Both of Sapium discolor and Sapium sebiferum are excellent ecological adaptability garden species which widely distributed in southwest and the Yangtze River basin and Southern China.To explore their water tolerance,the paper used 2 years old seedlings of S.discolor and S.sebiferum as test materials,simulation of natural flooding,through observation,determination and comparison their physiological changes under waterlogging stress,and using principal component analysis and subordinate function analysis method of waterlogging tolerance evaluation,study their waterlogging tolerance,the main results has beening gained as follows:(1)With the extension of waterlogging stress time,the relative water conductivity on leaves of S.discolor and S.sebiferum decreased,the height and caliper of relative growth rate decreased.In 14 d leaves of S.discolor turn red,S.sebiferum grow well.Adventitious root and lenticels of S.sebiferum emergence in 21 d,but S.discolor didn't.(2)The photosynthetic pigment content showed a decreasing trend,stomatal conductance first increased and then decreased,transpiration rate decreased;intercellular CO2 concentration,the net photosynthetic rate showed a declining trend,plant normal growth has been influenced.(3)Test 0-28 days,the content of MDA in S.discolor and S.sebiferum increased continuously,POD activity increased,S.discolor had a fast rise rate.SOD activity of S.discolor increased first,and then decreased after 21 d,but S.sebiferum sustained growth;In the period of the stress,POD activity of S.sebiferum always higher than S.discolor.At the initial stage of stress,the plant can adjust itself,with the aggravation of stress,and the growth is inhibited because the damage is more than the ability to bear.(4)After the waterlogging stress treatment,the soluble protein content S.sebiferum increased,gradually smooth after 14 d,the soluble protein content in S.discolor fluctuated within a certain range.At the initial stage of stress,the soluble sugar content in leaves of S.discolor and S.sebiferum increased,and then ZH group of S.discolor maintained at a high level,the LH group decreased after 21 d reached the peak,both ZH and LH group of S.sebiferum soluble sugar content increased which is higher than S.discolor after 14 d.Proline of S.discolor ZH and LH group declined slightly during 0-7d,after the rapid rise,ZH and LH group of S.sebiferum increased slowly.According to the principal component analysis,soluble sugar and soluble protein were the characteristic vector of the response to waterlogging stress,both of them have certain directive function to waterlogging tolerance.In conclusion,the waterlogging stress had significant effects on the growth and physiological and biochemical characteristics of S.discolor and S.sebiferum,both of them have certain waterlogging tolerance,combined with the actual situation,using principal component analysis and the subordinate function method,we know that waterlogging tolerance of S.sebiferum is relatively strong,the results are consistent with Cai Jinfeng et al,and the same category plant S.discolor is relatively weak,the difference is large.It has certain significance for domestication,introduction and afforestation technology of S.discolor.