玉米耐盐碱生理特性的杂种优势及遗传分析

Heterosis and Genetic Analysis of Physiological Characteristics of Salt and Alkali Tolerance in Maize

利用7个自交系进行4×3不完全双列杂交,获得12个杂交组合,在盐碱土和黑土条件下进行盆栽试验,调查苗期植株形态(株高、叶面积)与生理特性(SOD、POD活性),并进行杂种优势及遗传分析。结果表明,4个指标可以用于鉴定玉米的耐盐碱性,盐碱胁迫下玉米幼苗株高和叶面积降低,SOD、POD活性升高。不同自交系耐盐碱能力差异显著,根据4个指标及减少比例进行动态聚类,筛选出郑58是耐盐碱能力较强的自交系,Mo17对盐碱最敏感,5个中耐品种中昌7-2、444和B73偏敏感。杂交种间耐盐碱能力差异显著,郑单958、郑58×178、郑58×Mo17和黄C×178是耐盐碱性较高的杂交组合,444×Mo17是敏感组合。杂交种的耐盐碱性能与性状的杂种优势无关,与亲本的耐盐碱程度有关。4个指标的广义遗传力较高,非加性遗传的作用较突出。因此,筛选耐盐碱的自交系时既要考虑有关性状,又要考虑其性状对比非逆境条件下的变化率。

Using seven elite inbred lines,we prepared 12 hybrids by 4×3 incomplete diallel cross,then pot experiment were carried out for both parental inbred lines and hybrids with saline alkali soil and black soil.We investigated plant morphological feature and physiological characteristics at maize seedling stage,and then analyzed the heterosis and genetic parameter of each trait.The main results are that the investigated four traits can be used as index of evaluating maize salt tolerance.Under saline alkali stress,the plant height and leaf area of maize seedlings were both decreased,while the activities of SOD and POD were both increased.There are significant difference in salt and alkali resistance among inbred lines.Zheng 58 shows strong resistance to salt and alkali,while Mo17 is the most sensitive inbred line to salinity.Chang 7-2,444 and B73 were medium sensitive materials.There were signifi-cant difference in salt and alkali tolerance among hybrids.Zhengdan958,Zheng 58×178,Zheng 58×Mo17 and Huang C×178 were hybrids with high salt and alkaline resistance,while 444×Mo17 was a sensitive combination.Salt and alkali resistance was not related with heterosis,but related with the salinity tolerance ability of parents.Thebroad-sense heritabilities of the investigated four traits are all higher,especially non-additive effect is significant.Therefore,during breeding inbred line with high saline-alkali tolerance,both related trait and the change rate of associated trait under different conditions should be considered.