Resource Ecology, Resource Management Science and Department of Zoology, University of British Columbia, V6T 1W5, Vancouver, BC, Canada.
Theor Appl Genet. 1988 Sep;76(3):341-51. doi: 10.1007/BF00265333.
Reciprocal sets of homozygous inbred backcross lines were developed by crossing two pure line varieties (Baart 46 and Ramona) of Triticum aestivum L., followed by two backcrosses to each of the two parent varieties, and six to eight generations of selfing. Data on each inbred backcross line was obtained from twelve plots (from replications in three years). Five genes were responsible for over 95% of the genetic variation for heading date. These genes had pleiotropic effects on plant height that were proportional to their effects on heading date. Two additional genes had detectable effects on plant height. The genes with a measurable effect on height accounted for 90% of the genetic variation in the Baart 46 genetic background. One gene affected seed weight. In the Ramona background, this gene accounted for 80% of the genetic variation in seed weight and 16% of the genetic variation in seed yield. Two genes, responsible for the earliest and latest heading date classes, had large pleiotropic effects on seed yield. They accounted for 60% of the genetic variation in yield. One gene, with no effect on heading date, caused a detectable reduction in yield of 23% in the Baart 46 inbred backcross lines. This gene had no apparent effect in the Ramona genetic background. Quantitative trait genes are sparsely distributed in the genome: fewer than one in four chromosome arms carries a gene with a detectable effect. Gene effects on quantitative traits are not small and similar. The distribution of 22 gene effects for heading date and height is slightly skewed to the right: as the magnitude of effect increases, the frequency of genes having the effect decreases.
通过杂交两个纯系品种（Baart 46 和 Ramona）小麦，然后回交两次到两个亲本品种，再自交六到八代，培育出了互为纯合近交系回交系。每个近交系回交系的数据都来自于 12 个小区（来自三年的重复）。五个基因负责 95%以上的抽穗期遗传变异。这些基因对株高有多种影响，与对抽穗期的影响成正比。另外两个基因对株高有可检测的影响。对株高有可测量影响的基因占 Baart 46 遗传背景中遗传变异的 90%。一个基因影响种子重量。在 Ramona 背景下，该基因占种子重量遗传变异的 80%和种子产量遗传变异的 16%。两个基因，负责最早和最晚的抽穗期，对种子产量有很大的多效性影响。它们占产量遗传变异的 60%。一个对抽穗期没有影响的基因，导致 Baart 46 近交系回交系的产量降低了 23%。这个基因在 Ramona 遗传背景下没有明显的影响。数量性状基因在基因组中分布稀疏：不到四分之一的染色体臂携带一个具有可检测效应的基因。基因对数量性状的影响不小而且相似。22 个抽穗期和高度的基因效应分布略有右偏：随着效应幅度的增加，具有该效应的基因频率降低。
