三倍体白榆对NaCl胁迫的生长及生理响应

Growth and Physiological Response of Triploid Ulmus pumila to NaCl Stress

为研究三倍体白榆盐胁迫响应特性,以三倍体白榆无性系为试材,测定0.9%土壤含盐量下5个不同胁迫时间(0、7、14、21、28 d)的生长、生理生化指标的变化。结果表明:在NaCl胁迫0d与胁迫28 d三倍体白榆的株高、相对高生长均显著高于二倍体白榆;不同倍性白榆随着盐胁迫时间的延长,相对电导率(REC)、丙二醛(MAD)含量逐渐上升,净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间二氧化碳浓度(Ci)及叶绿素(Chl)含量逐渐下降,三倍体白榆叶片REC、MDA含量、Pn、Tr、Gs、Ci、Chl变化较二倍体缓慢;不同倍性白榆超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)均随盐胁迫时间的延长表现出先升再降的趋势,各处理时间下三倍体白榆SOD、POD、CAT活性均高于二倍体白榆;不同倍性白榆可溶性糖(SS)含量随处理时间的延长逐渐上升,二倍体白榆可溶性蛋白(SP)含量随处理时间的延长呈先升后降的趋势,三倍体白榆SP含量随处理时间的延长呈逐渐上升趋势,各处理时间下三倍体白榆SS含量、可溶性蛋白SP含量均高于二倍体白榆。三倍体白榆在NaCl胁迫下光合系统受损伤程度更小,抗氧化能力及细胞稳定性较二倍体更强,具有更强耐盐性。

In order to study the salt stress response characteristics of triploid Ulmus pumila,the triploid Ulmus pumila asexual lines were used as test material to determine the changes of growth,physiological and biochemical indexes in five different stress times(0 d,7,14,21 d and 28 d)under 0.9%NaCl treatment.The results showed that the plant height and relative tall growth of triploid Ulmus pumila were significantly higher than that of diploid Ulmus pumila at 0 d and 28 d of NaCl stress;with the extension of the salt stress time,the relative conductivity(REC)and malondialdehyde(MAD)content of Ulmus pumila of different ploidy increased gradually,and the net photosynthesis rate(Pn),transpiration rate(Tr),stomatal conductance(Gs),intercellular carbon dioxide concentration(Ci)and Chlorophyll(Chl)content gradually decreased,triploid Ulmus pumila leaves REC,MDA content,Pn,Tr,Gs,Ci,Chl changes more slowly than the diploid;different ploidy of Ulmus pumila superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)with the prolongation of the time of salt stress showed a trend of rise and then decline,the time of the treatment of the triploid Ulmus pumila SOD,POD and CAT activities were higher than those of diploid Ulmus pumila;the soluble sugar(SS)content of different ploidy Ulmus pumila increased gradually with the extension of treatment time,the soluble protein(SP)content of diploid Ulmus pumila showed a trend of increasing and then decreasing with the extension of treatment time,while the SP content of triploid Ulmus pumila showed a trend of increasing gradually with the extension of treatment time,and the SS content and soluble protein content of triploid Ulmus pumila were higher than that of diploid Ulmus pumila with the extension of each treatment time.SP content was higher than that of diploid Ulmus pumila.The photosynthetic system of triploid Ulmus pumila was less damaged under NaCl stress,and the antioxidant capacity and cell stability were stronger than those of diploid Ulmus pumila,which had stronger salt tolerance.