碱胁迫对菊芋幼苗生长及其光合作用和抗氧化作用的影响  

Effects of Alkaline Stress on Growth,Photosynthesis and Antioxidation of Helianthus tuberosus Seedlings

作　　者：吴成龙[1] 尹金来[2] 徐阳春[1] 刘兆普[1] 沈其荣[1] 周春霖[3] 

机构地区：[1]南京农业大学资源与环境学院,南京210095 [2]江苏省阜宁县人民政府,江苏阜宁224400 [3]盐城师范学院江苏省滩涂生物资源与环境保护重点实殓室,江苏盐城224002

出　　处：《西北植物学报》2006年第3期447-454,共8页Acta Botanica Boreali-Occidentalia Sinica

基　　金：江苏省自然科学基金项目(BK2003201);江苏省"十五"农业科技攻关课题(BE201337)

摘　　要：采用砂培试验研究了碱胁迫(0、12.5、25.0、37.5和50.0 mm o l.L-1N a2CO3)对2种菊芋(H elianthustuberosus L.)南芋8号(H t 1)和南芋1号(H t 2)幼苗生长及其光合作用和抗氧化作用的影响。结果表明,2种菊芋耐碱的极限浓度为50.0 mm o l.L-1;碱胁迫,尤其是高浓度(37.5 mm o l.L-1)的胁迫,显著降低菊芋幼苗总鲜重、净光合速率(Pn)、气孔导度(G s)、蒸腾速率(T r)、水分利用效率(WUE)及叶绿素总量(Ch l a+Ch l b)、类胡萝卜素(C aro)含量与叶片和根POD活性,而显著提高细胞间隙CO2浓度(C i)、叶片和根SOD活性以及丙二醛(M DA)含量。此外,H t 1叶绿素a/b(Ch l a/Ch l b)在碱胁迫下没有明显变化,而H t 2却明显降低。这些结果表明非气孔限制是碱胁迫下2种菊芋幼苗Pn降低的主要原因。菊芋品种H t 1幼苗耐碱能力大于菊芋品种H t 2,这可能与H t 1碱胁迫下维持了较高的Pn、G s、T r、WUE、Ch l a/Ch l b、C aro含量、SOD和POD活性和较低的M DA含量有关。The effects of alkaline stress （0,12.5,25.0,37.5 and 50.0 mmol· L^-1 Na2CO3） of the growths, photosynthesis and anti-oxidations of the seedlings of two Helianthus tuberosus L. varieties,Nayu 8 （Ht1） and Nanyu 1 （Ht2）,were studied by sand culture. The results showed that the ceiling concentrations for the two varieties to be able to tolerate alkaline stress was 50.0 mmol· L^-1 In Helianthus tuberosus L. seedlings,the alkaline stress,especially stress at high Na2CO3 concentration,significantly reduced the total fresh weight, net photosynthetic rate, stomatal conductance, transpiration rate, water use efficiency, total chlorophyll amount （chla and b） ,carotene content ,and POD activities in the roots ,but increased the intercellular CO2 concentration,and SOD activities and MDA contents in the roots and leaves. Besides,Chla/b did not vary with alkaline stress in Htl but remarkably declined in Ht2. These revealed that non-stomatal constraint was the main reason why the seedlings of the two varieties had decreased Pn under alkaline stress. The variety Htl had a stronger alkaline tolerance than the variety Ht2 did,which might have something to do with that Htl maintained its Pn,stomatal conductance,transpiration rate,water use efficiency and Chla/b and carotene content at a high level and its SOD and POD activities at a low level and a low MDA content.

关 键 词：菊芋 碱胁迫 光合作用 抗氧化作用 

分 类 号：Q945.78[生物学—植物学]