抗旱型玉米苗期根系性状的主基因+多基因遗传模型分析

Root characteristics of drought resistant maize at seedling stage based on the mixed major gene plus polygene inheritance model

【目的】揭示抗旱型玉米苗期根系表型性状的遗传特性,为玉米根系耐旱性状的定向改良提供理论依据。【方法】以干旱敏感型材料WN897(母本)、抗旱型材料WU109(父本)及其杂交和回交产生的F_(1)、B_(1)、B_(2)和F_(2)为材料,采用主基因+多基因混合遗传模型,对干旱胁迫和正常条件下玉米的总根长、根表面积、根投影面积和根体积进行遗传分析。【结果】在干旱胁迫和正常条件下,玉米的总根长、根投影面积、根表面积和根体积的遗传率均较高,环境变化对其影响较小。在干旱胁迫条件下,玉米总根长和根投影面积的最优遗传模型均为E(2对加性-显性-上位性主基因+加性-显性-上位性多基因模型),B_(1)、B_(2)、F_(2)的主基因遗传率分别为51.37%,68.46%,65.69%和50.01%,56.28%,77.63%;根表面积的最优遗传模型为E-1(2对加性-显性-上位性主基因+加性-显性多基因混合遗传模型),B_(1)、B_(2)、F_(2)的主基因遗传率为31.92%,61.96%,72.96%;根体积的最优遗传模型为D(1对加性-显性主基因+加性-显性-上位性多基因遗传模型),B_(1)、B_(2)、F_(2)的主基因遗传率为0.64%,0.64%,0.91%。在正常条件下,玉米总根长、根表面积和根体积的最优遗传模型均为E-1,B_(1)、B_(2)、F_(2)的主基因遗传率分别为65.20%,68.42%,75.72%;56.38%,42.65%,72.13%及61.36%,44.26%,78.55%,根投影面积的最优遗传模型为E,B_(1)、B_(2)、F_(2)的主基因遗传率为55.27%,51.84%,48.97%。【结论】玉米总根长、根表面积可以在低世代材料中进行有效选择。干旱条件下对玉米根投影面积的选择效率更高。正常条件下玉米根体积在低世代材料中即可进行有效选择,但干旱条件下需在高世代材料中进行有效选择。

【Objective】This study revealed the inheritance of root traits of drought resistant maize at seedling stage to provide basis for improving drought resistance.【Method】In this study,drought sensitive material WN897 and drought resistant material WU109 as well as their crossed populations(F_(1),F_(2),B_(1) and B_(2))were selected.The mixed major gene plus polygene inheritance model was applied to conduct inheritance analysis on total root length,root projected area,root surface area and root volume.【Result】Under drought stress and normal conditions,the heritability of total root length,root projection area,root surface area and root volume of maize was high,and environmental changes had less effect.Under drought stress conditions,the optimal genetic model for total root length and root projection area was E(2 pairs of additive-dominant-epistatic major genes+additive-dominant-epistatic polygene model),and heritability rates of major genes of B_(1),B_(2) and F_(2) were 51.37%,68.46%,65.69%and 50.01%,56.28%,77.63%.The optimal genetic model for root surface area was E-1(2 pairs of additive-dominant-epistatic major genes+additive-dominant polygene mixed inheritance model),and heritability rates of major genes of B_(1),B_(2) and F_(2) were 31.92%,61.96%,72.96%.The optimal genetic model for root volume was D(1 pair of additive-dominant major gene+additive-dominant-epistatic polygene inheritance model),and heritability rates of major genes of B_(1),B_(2) and F_(2) were 0.64%,0.64%,0.91%.Under normal conditions,the optimal genetic model for maize total root length,root surface area and root volume was E-1(2 pairs of additive-dominant-epistatic major genes+additive-dominant polygene mixed inheritance model),and heritability of major genes of B_(1),B_(2) and F_(2) were 65.20%,68.42%,75.72%and 56.38%,42.65%,72.13%and 61.36%,44.26%,78.55%;the optimal genetic model for root projection area was E(2 pairs of additive-dominant-epistatic major genes+additive-dominant-epistatic polygene model),and heritability rates of major genes of B_(1),B_(2) and F_(2) were 55.27%,51.84%,48.97%.【Conclusion】Total root length and root surface area had effective selection in low generation materials.Root projected area had effective selection efficiency under drought stress.Root volume had effective selection in low generation materials under normal conditions,while it had effective selection in high generation materials under drought conditions.