【摘要】 耐冷性是植物对低温环境适应能力的重要体现,甜瓜（Cucumis melo）作为低温敏感植物,其耐冷性遗传方式尚不明确。为探明控制甜瓜苗期耐冷性的遗传模型及基因作用方式,本研究以耐冷、冷敏甜瓜自交系构建了6世代遗传群体,采用主基因+多基因混合遗传模型研究春秋两季甜瓜苗期耐冷性的遗传规律。结果显示,甜瓜苗期耐冷性呈现明显的数量性状特征,趋向显性遗传,其遗传模型符合2对加性-显性-上位性主基因+加性-显性多基因模型。主基因的效应以显性效应为主,同时也具有较强的互作效应,且易受环境因素的影响。B_1∶2、B_2∶2和F_2∶3世代在春季的主基因遗传率分别为73.22%、92.36%和95.57%,秋季的主基因遗传率分别为49.58%、84.15%和83.18%,多基因遗传率较低且仅在B_1∶2世代中检测到。主基因在F₂及其自交后代、B₂与冷敏亲本回交后代中的早期选择效率较高,B₁世代可加强多基因的选择。本研究为甜瓜苗期耐冷性遗传改良提供了参考依据。更多还原

【Abstract】 Chilling tolerance is an important reflection on the ability of plant to adopt to low-temperature environment. Melon（Cucumis melo） is sensitive to low temperature, but the genetic pattern for chilling tolerance of melon seedlings remained unclear to date. In the present study, 2 melon inbred lines, which showed tolerance and sensitive to low temperature, were used to develop 6 generation populations for joint analysis, aiming to pinpoint the genetic model controlling chilling tolerance of melon seedlings and function model of the genes related to the trait. For this analysis, a mixed major-gene plus polygenes inheritance model was applied for pursuing the inheritance law of chilling tolerance of melon seedlings in spring and autumn.The results showed that chilling tolerance had typical characters of quantitative traits and tended to inherit dominantly. The optimal genetic pattern fitted 2 pairs of additive-dominance-epitasis major genes plus additive-dominant polygene model. Dominant effects played a main role for the major genes, meanwhile epistatic effects were also observed with these genes. All the gene effects were sensitive to environmental factors. Three generation populations(B_1∶2, B_2∶2 and F_2∶3) had a major gene heritability of 73.22%, 92.36% and95.57% in spring and 49.58%, 84.15% and 83.18% in autumn, respectively. The heritability of polygene was much low, only being detected in B_1∶2 generation. Selection efficiency of major genes was much high in the early generations of F₂ and its self-bred progenies as well as the backcross progenies（B₂×sensitive parent）. B₁ generation could be more suitable for selection for polygenes. The present study could provide a reference for genetic improvement of chilling tolerance of melon seedlings.更多还原