| The threat of soil salinization to agriculture is a global issue, which leads to crop failure in the worldwide. Barley, one of the high salt tolerant crops, is used as the prior crop for reclamation of saltern. The study of barley salt tolerance and the identification of salt tolerant germplasm are paid more attention. Based on previous research, the hybrids of the salt tolerant barley variety Taixing9425and salt sensitive barley variety Nasonijiao was used to construct DH population by anther culture in this study. Under the condition of300mM NaCl, the salt tolerance of188DH individual and their two parents was identified in seedling with three leaves period by nutrient solution. The salt-free control was also carried out. After treatment, the main traits of treated and controlled seedlings’ were" investigated. The salt tolerance diversity of DH individual was evaluated by ANOVA a’nalysis and cluster analysis with the difference of phenotype and the relative salt tolerant rate as index. The salt tolerant QTLs were located by the molecular markers provided by Professor Zhou Meixue worked in University of Tasmania. The main results were as follows:1) The development of barley DH population traits in seedling stage were inhibited significantly under the condition of300mM NaCl. The salt tolerance of parent Taixing9425was better than that of Nasonijiao by the identification and analysis of parents’salt tolerance diversity. The identification and statistical analysis of individual in the DH population indicated that the individuals had significant difference in this population.2) According to the3results of different cluster analysis, the barley code T45067,T45075,T45079,T45098,T45198,T45206,T45207,T45208,T45209,T45210.T45232, T45235,T45236,T45237,T45240,T45241,T45244,T45245,T45246,T45248,T45249,T45306,T45336and T45340were salt tolerant or less salt tolerant DH lines while the barley code T45010,T45219,T45286,T45305,T45343and T45376were the most sensitive DH lines.3) QTL mapping of stem and leaf characters, relative salt tolerance level under the control and treat level have been analyzed combining with the phenotype value of parents and188DH lines and molecular markers. The results showed that some QTLs for the same or different characters in different conditions had been detected repeatedly on the chromosome of1H,2H,3H and7H.6overlapping or adjacent QTLs on the chromosome1H were located at the marker interval of bPb-0910-bPb-8736including the qTNI1-1which was conferring to the relative salt tolerance of tillers with the genetic distance of61.39cM. There were7overlapping or adjacent QTLs identified between the markers bPb-6792and bPb-4740on the chromosome2H, including qFWI2-3, qDWI2-3, qDWI2-4and qSTR2-2which were associated with the relative salt tolerance of the fresh weight and dry weight of stem and leaf and the level respectively.9QTLs located at another intervals of bPb-8292-bPb-4821were also detected on the chromosome2H including q FWI2-6, q FWI2-7for the fresh weight of stem and leaf and qSTR2-5, qSTR2-6for tolerance level.11overlapping QTLs were located on the interval bPb-6923-Bmag0006on chromosome3H, of which qSHs3-1, qSHs3-2and qSHs3-3related to plant height under treated condition exist.7overlapping QTLs were located on the interval HVCMA-bpb-1050on chromosome7H. Among.the7QTLs, qFWs7-2and qFWs7-4related to fresh weight of stem and leaf under treated condition. qDWs7-2and qDWs7-3related to dry weight of stem and leaf under treated condition. qFWI7-1related to relative salt tolerance rate of fresh weight of stem and leaf under treated condition. qDWI7-1and qDWI7-2related to relative salt tolerance rate of dry weight of stem and leaf under treated condition. The situation that2or3QTLs were located on identical locus or close loci on chromosome1H,2H and5H. These QTLs located on same locus or close loci may relate to the salt tolerance of barley seedlings, which need further confirmation by using reliable molecular markers. |
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