Zhao Jianyi, Becker Heiko C, Zhang Dongqing, Zhang Yaofeng, Ecke Wolfgang
Crop Research Institute, Zhejiang Academy of Agricultural Sciences, 310021 Hangzhou, People's Republic of China.
Theor Appl Genet. 2006 Jun;113(1):33-8. doi: 10.1007/s00122-006-0267-5. Epub 2006 Apr 14.
Oil content in rapeseed (Brassica napus L.) is generally regarded as a character with high heritability that is negatively correlated with protein content and influenced by plant developmental and yield related traits. To evaluate possible genetic interrelationships between these traits and oil content, QTL for oil content were mapped using data on oil content and on oil content conditioned on the putatively interrelated traits. Phenotypic data were evaluated in a segregating doubled haploid population of 282 lines derived from the F(1) of a cross between the old German cultivar Sollux and the Chinese cultivar Gaoyou. The material was tested at four locations, two each in Germany and in China. QTLMapper version 1.0 was used for mapping unconditional and conditional QTL with additive (a) and locus pairs with additive x additive epistatic (aa) effects. Clear evidence was found for a strong genetic relationship between oil and protein content. Six QTL and nine epistatic locus pairs were found, which had pleiotropic effects on both traits. Nevertheless, two QTL were also identified, which control oil content independent from protein content and which could be used in practical breeding programs to increase oil content without affecting seed protein content. In addition, six additional QTL with small effects were only identified in the conditional mapping. Some evidence was apparent for a genetic interrelationship between oil content and the number of seeds per silique but no evidence was found for a genetic relationship between oil content and flowering time, grain filling period or single seed weight. The results indicate that for closely correlated traits conditional QTL mapping can be used to dissect the genetic interrelationship between two traits at the level of individual QTL. Furthermore, conditional QTL mapping can reveal additional QTL with small effects that are undetectable in unconditional mapping.
油菜籽（甘蓝型油菜）中的含油量通常被视为一种遗传力较高的性状，它与蛋白质含量呈负相关，并受植株发育及产量相关性状的影响。为了评估这些性状与含油量之间可能存在的遗传相互关系，利用含油量数据以及假定相关性状条件下的含油量数据，对含油量的数量性状位点（QTL）进行了定位。在一个由德国老品种索路克斯（Sollux）与中国品种高邮杂交所得F1代衍生而来的、包含282个株系的双单倍体分离群体中，对表型数据进行了评估。该材料在四个地点进行了测试，德国和中国各两个地点。使用QTLMapper 1.0版本来定位具有加性（a）效应的无条件和条件QTL以及具有加性×加性上位性（aa）效应的位点对。有明确证据表明油分和蛋白质含量之间存在很强的遗传关系。发现了6个QTL和9个上位性位点对，它们对这两个性状都有 pleiotropic 效应。然而，也鉴定出了2个QTL，它们独立于蛋白质含量控制含油量，可用于实际育种计划中在不影响种子蛋白质含量的情况下提高含油量。此外，另外6个效应较小的QTL仅在条件定位中被鉴定出来。有一些证据表明含油量与每角果种子数之间存在遗传相互关系，但未发现含油量与开花时间、灌浆期或单粒重之间存在遗传关系。结果表明，对于紧密相关的性状，条件QTL定位可用于在单个QTL水平上剖析两个性状之间的遗传相互关系。此外，条件QTL定位可以揭示在无条件定位中无法检测到的、效应较小的额外QTL。
