利用隶属函数值法对玉米成熟期耐盐性的综合评价

Comprehensive evaluation of salt-tolerance of maize at mature period using subordinate function value analysis

【目的】筛选耐盐、敏盐的玉米种质资源,为耐盐玉米育种研究提供理论依据。【方法】于2016年4-9月,在宁夏银川,以10个不同基因型春玉米品种为试验材料,设置盐分含量不同的2块地:对照田(土壤全盐含量低,为0.612g/kg)和盐碱胁迫地(土壤全盐含量中度,为2.269g/kg),两地块间土壤养分含量无明显差异,测定两地块中成熟期各玉米品种的K^+/Na^+,光合气体交换参数(有效光照强度(PAR)、净光合速率(P^n)、蒸腾速率(Tr)、气孔导度(Gs)、叶温(T^L))以及农艺性状和产量等指标,利用主成分分析和隶属函数值法对不同基因型玉米品种耐盐性强弱进行综合评价。【结果】与对照相比,盐碱胁迫条件下各玉米品种的根系和茎基部K^+/Na^+值均明显降低(P<0.05),且同一品种不同器官的K^+/Na^+总体表现为茎>叶片>茎基部>根系,表明离子的吸收和运输具有选择性,其中茎具有贮存K^+的作用,根系具有贮存Na^+的功能。盐碱胁迫下各玉米品种的净光合速率(P^n)总体均显著低于对照(P<0.05),叶片温度(T^L)显著高于对照(P<0.01),其他光合指标无明显变化规律。此外,盐碱胁迫条件下,各玉米品种的农艺性状和产量较对照均降低。【结论】不同基因型玉米品种之间的耐盐碱能力存在差异,根据综合评价值(D值)大小,耐盐性由强到弱顺序为WY_2>宁3/1522>A3/A18>HoViY1>A111-3/H242>H237/A18>桂青贮1号>A3/A18高>北21/A58>H237/1506。

【Objective】This study screened the germplasm resources of maize with salt tolerance and salt sensitivity to provide theoretical basis for salt tolerance breeding.【Method】During April to September 2016,10 maize cultivars were planted in saline land（soil total salt content of 2.269 g/kg）and control land（soil total salt content of 0.621 g/kg）in Yinchuan,Ningxia.There was no difference in the soil chemical characters between the two experimental lands.K~＋/Na~＋ ,photosynthetic physiological exchange parameters including effective light intensity（PAR）,net photosynthetic rate（P_n）,transpiration rate（Tr）,stomatal conductance（Gs）and leaf temperature（T_L）,agronomic characters and yield were determined in mature stage.Then,the salt tolerances of the tested genotypes were comprehensively evaluated by principal compo-nent analysis and the subordinate function method.【Result】Compared with control,the K~＋/Na~＋ of root and basal stem of maize varieties were significantly decreased under saline-alkali stress（P0.05）.The K~＋/Na~＋ ratios in different parts were in the order of stem leafbasal stem root,suggesting the selectiveness for maize in ion uptake and transportation as well as the ability to store Na~＋ in root and K~＋in stem.Net photosynthetic rate（P_n）was significantly lower under salt-alkali stress treatment than those in control（P0.05）,while leaf temperature（T_L）was significantly higher than those in control（P0.01）,other photosynthetic indexes had no obvious law.The average agronomic traits and yield were all decreased compared with control.【Conclusion】According to synthetic evaluation value（D）,the comprehensive evaluation indicated that the salt-tolerances of the ten maize varieties were in the order of WY_2Ning3/1522A3/A18HoViY1A111-3/H242H237/A18Gui silage 1A3/A18 GaoNorth 21/A58H237/1506.