Faculty of Horticulture, Department of Vegetable Science, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur 741 252, India.
J Genet. 2020;99.
Okra production in eastern India at present is severely threatened by whitefly-mediated okra enation leaf curl disease (OELCuD). Identification of resistant genotype and understanding the genetic control and biochemical relationship of OELCuD resistance are prerequisite for developing an effective breeding strategy. This study was conducted employing six populations (P, P, F, F, BC and BC) of two selected (resistant x susceptible (RxS)) crosses. Associationship between severity of OELCuD and biochemical parameters of parents and hybrids at preflowering and flowering stages was studied. Segregation pattern of the genotypes in F generation showing OELCuD reaction of two crosses suggested that two duplicate recessive genes was operative for resistance to OELCuD. Generation mean analysis revealed involvement of both additive and nonadditive effects in the inheritance of disease resistance. Hence, postponement of selection in later generations or intermating among the selected segregates followed by one or two generations of selfing to break the undesirable linkage and allow the accumulation of favourable alleles could be suggested for the development of stable resistant genotype against this disease. Higher peroxidase activity and total phenol content in leaf emerged as reliable biochemical markers for early selection of genotype resistant to OELCuD.
目前，印度东部的秋葵生产受到烟粉虱介导的秋葵卷叶卷曲病（OELCuD）的严重威胁。鉴定抗性基因型，了解 OELCuD 抗性的遗传控制和生化关系，是制定有效育种策略的前提。本研究采用两个选定的（抗性 x 敏感（RxS））杂交的六个群体（P、P、F、F、BC 和 BC）进行。在开花前和开花期研究了 OELCuD 严重程度与父母本和杂种生化参数之间的关联。在表现出两种杂交 OELCuD 反应的 F1 代基因型的分离模式表明，两个重复的隐性基因对 OELCuD 具有抗性。世代均值分析表明，疾病抗性的遗传涉及加性和非加性效应。因此，建议在后代中推迟选择，或者在选择的分离群体中进行互交，然后进行一到两代自交以打破不良连锁，允许有利等位基因的积累，从而开发出对这种疾病具有稳定抗性的基因型。叶片中较高的过氧化物酶活性和总酚含量可作为早期选择对 OELCuD 具有抗性的基因型的可靠生化标记。
