3个玉米自交系对盐胁迫的生理响应及耐盐性评价

以自交系M-2导入系、Hr30导入系和Mo17导入系为试验材料,研究不同浓度NaCl(0、100 mmol·L~(-1)、150 mmol·L~(-1)、200 mmol·L~(-1)、250 mmol·L~(-1))对3个玉米幼苗的超氧化物歧化酶(SOD)、过氧化物酶(POD)、可溶性蛋白等生理指标的变化规律的影响,并采用主成份分析与隶属函数相结合的方法对其耐盐性进行综合评价,旨在为玉米耐盐性筛选及抗盐新品种的选育奠定基础。结果表明,3个自交系的株高、生物量、叶绿素含量、净光合速率(Pn)以及可溶性蛋白质的含量大体上随着盐浓度的增加而呈下降的趋势;根长、相对电导率、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性和根冠比大体上呈先上升后下降的趋势。利用主成份分析归纳出株高、净光合速率(Pn)、丙二醛(MDA)等9个与耐盐密切相关的生理指标,运用模糊数学隶属函数分析得出,3个玉米自交系的耐盐性强弱依次为M-2导入系Hr30导入系Mo17导入系。

Physiological responses and tolerance of three maize inbred lines to salt stress

Using three maize inbred lines (including M-2 introgression line,Hr30 introgression line,and Mo17 introgression line) as test materials,an experiment was conducted to investigate the effects of different concentratiom of NaCl(0 mmol·L-1,100 mmol·L-1,150 mmol·L-1,200 mmol·L-1,and 250 mmol·L-1)on physiological parameters such as superoxide dismutase (SOD) activity,peroxidase (POD) activity and malondialdehyde (MDA) content in maize seedlings.Furthermore,the salt tolerance of these three inbred lines was comprehensively evaluated by the methods of principal components analysis and fuzzy subordinate function,so as to lay foundation of identifying salt tolerance and selecting salt-tolerant cultivars of maize.The results showed that,with the increase of salt concentration,the plant height,biomass,chlorophyll content,net photosynthetic rate (Pn) and soluble protein content in all three inbred lines tended to decrease,while the root length,relative conductivity,MDA content,SOD activity,POD activity and root/ shoot ratio were increased at first and decreased subsequently.According to the results of principal components analysis,9 parameters (including plant height,Pn,MDA contem,SOD activity and so on) were closely related to salt tolerance.Through the analysis of fuzzy subordinate function,the salt-resistant capabihty of tested inbred lines was ranked as:M2 introgression line ＞ Hr30 introgression line ＞ Mo17 introgression line.