Inheritance of leaf color in papaya

Abstract Physiological disturbances are one of the major bottlenecks to the expansion of papaya crops due to the negative influence on fruit quality. Studies on genotypes of light-green color have become essential to the development of strategies of tolerance to the physiological disorder skin freckle. Understanding the inheritance of qualitative traits is crucial to selection and prediction of the behavior of segregating generations. Thus, this study aimed to determine the inheritance of the qualitative trait leaf color in segregating generations of crosses between the dark-green cultivar BSA and the light-green cultivar GPC. Inheritance was determined based on the Mendelian genetics laws, by evaluating the phenotypic proportions in the analysis of generations P1 (BSA), P2 (GPC), F1, F2, BC1, BC2, BC2r, and F2:3. The inheritance of light-green leaves from the crossing between BSA and GPG is due to double recessive epistasis.

摘要 生理紊乱会对番木瓜果实品质产生负面影响，是制约番木瓜产业规模化扩张的核心瓶颈之一。针对浅绿基因型的相关研究，对研发应对果皮斑点生理病害（skin freckle）的耐受策略至关重要。解析质量性状（qualitative traits）的遗传规律，对分离世代（segregating generations）的性状选择与表现预测具有关键意义。为此，本研究以深绿色品种BSA与浅绿色品种GPC杂交产生的分离群体为材料，旨在解析叶片颜色这一质量性状的遗传模式。本研究基于孟德尔遗传定律（Mendelian genetics laws），通过分析亲本P1（BSA）、P2（GPC）、F1、F2、回交一代BC1、回交二代BC2、回交二代回交群体BC2r以及F2:3家系的表型比例，确定了该性状的遗传模式。BSA与GPC杂交组合的浅绿叶色性状，其遗传模式为双隐性上位性（double recessive epistasis）。