不同基因型玉米杂交种大喇叭口期的耐盐性

以25个不同基因型玉米品种为试验材料,在宁夏银北盐碱地(土壤含盐量为2.337~6.935 g·kg~(-1)),通过测定不同品种大喇叭口期的表型性状和生理生化指标进行耐盐性鉴定,并利用主成分分析和模糊隶属函数法对不同基因型玉米品种的耐盐性强弱进行综合评价。结果表明:随着盐胁迫程度的增加,不同玉米品种的株高、茎粗、相对叶绿素含量(SPAD值)均明显降低;轻度胁迫(土壤含盐量为2.337 g·kg~(-1))时,株高、茎粗、SPAD三者之间均呈极显著正相关;严重胁迫(土壤含盐量为6.935 g·kg~(-1))时,茎粗、SPAD值、冠层温度三者之间均呈显著正相关,冠层温度与超氧化物歧化酶(SOD)呈显著负相关,膜透性与SOD呈极显著正相关,其它各农艺性状与生理指标间均没有达到显著相关。不同基因型玉米品种的耐盐碱能力根据综合评价值(D值)大小来评价,将耐盐碱性分为四级:宁3-2/1528、A3高/1519为A类的玉米材料,其D值0.8,代表强耐盐性的品种;B类的玉米材料有6份,其0.6D值0.8,代表较耐盐性的品种;C类的玉米材料有12份,其由0.4D值0.6,代表弱耐盐性的品种;D类的玉米材料有5份,分别为H242/1522、北21/1522、A18/1506、A49/1528、TY1,其D值0.4,代表盐敏感性品种。

Salt tolerance of different genotypes maize at the big flare stage

In order to evaluate salt tolerance of different maize genotypes, 25 varieties/lines were planted in saline-alkali land subjected to salt stress in northern Ningxia, Yinchuan, with the soil salt contents being 2.337, 3.044 g·kg^-1 and 6.935 g·kg^-1). Based on phenotypes and physiological indexes measured at big flare stage, salt tolerance of the 25 maize genotypes were evaluated through principal component analysis and the subordinate function method. The results showed that plant height, stem diameter, relative chlorophyll content (SPAD values) were significantly decreased with the increase of salt stress. At mild stress (the soil salt content was 2.337 g·kg^-1), there was a significant positive correlation between plant height, stem diameter and SPAD. Under severe stress (the soil salt content was 6.935 g·kg^-1), there was a significant positive correlation between stem diameter, SPAD values and canopy temperature, and canopy temperature had a significantly negative correlation with superoxide dismutase (SOD). Membrane permeability and SOD were extremely significant positive correlated, and other agronomic traits and physiological indexes were not significantly correlated. According to comprehensive evaluation, the salt tolerance of maize varieties was divided into highly salt tolerant, salt tolerant, salt susceptible and highly salt susceptible.