Lark K G, Chase K, Adler F, Mansur L M, Orf J H
Department of Biology, University of Utah, Salt Lake City 84112, USA.
Proc Natl Acad Sci U S A. 1995 May 9;92(10):4656-60. doi: 10.1073/pnas.92.10.4656.
A large recombinant inbred population of soybean has been characterized for 220 restriction fragment-length polymorphism (RFLP) markers. Values for agronomic traits also have been measured. Quantitative trait loci (QTL) for height, yield, and maturity were located by their linkage to RFLP markers. QTL controlling large amounts of trait variation were analyzed for the dependence of trait variation on particular alleles at a second locus by comparing cumulative distributions of the trait for each genotype (four genotypes per pair of loci). Interesting pairs of loci were analyzed statistically with maximum likelihood and Monte Carlo comparison of additive and epistatic models. For each locus affecting height, variation was conditional upon the presence of a particular allele at a second unlinked locus that itself explained little or no trait variation. The results show that interactions between QTL are frequent and control large effects. Interactions distinguished between different QTL in a single linkage group and between QTL that affect different traits closely linked to one RFLP marker--i.e., distinguished between pleiotropy and closely linked genes. The implications for the evolution of inbreeding plants and for the construction of agronomic breeding strategies are discussed.
一个大型的大豆重组自交群体已针对220个限制性片段长度多态性（RFLP）标记进行了特征分析。同时也测定了农艺性状的值。通过与RFLP标记的连锁关系定位了控制株高、产量和成熟度的数量性状基因座（QTL）。通过比较每个基因型（每对基因座有四种基因型）的性状累积分布，分析了控制大量性状变异的QTL在第二个基因座上性状变异对特定等位基因的依赖性。使用最大似然法以及加性和上位性模型的蒙特卡罗比较，对有趣的基因座对进行了统计分析。对于每个影响株高的基因座，变异取决于第二个不连锁基因座上特定等位基因的存在，而该基因座本身对性状变异的解释很少或没有解释。结果表明，QTL之间的相互作用很频繁且具有很大影响。相互作用区分了单个连锁群中不同的QTL以及影响与一个RFLP标记紧密连锁的不同性状的QTL，即区分了多效性和紧密连锁的基因。文中讨论了这些结果对自交植物进化以及农艺育种策略构建的意义。
