Bradshaw H D, Stettler R F
Center for Urban Horticulture GF-15, University of Washington, Seattle 98195, USA.
Genetics. 1995 Feb;139(2):963-73. doi: 10.1093/genetics/139.2.963.
We have mapped quantitative trait loci (QTLs) for commercially important traits (stem growth and form) and an adaptive trait (spring leaf flush) in a Populus F2 generation derived from a cross between interspecific F1 hybrids (P. trichocarpa x P. deltoides). Phenotypic data were collected over a 2-year period from a replicated clonal trial containing ramets of the parental, F1, and F2 trees. Contrary to the assumptions of simple polygenic models of quantitative trait inheritance, 1-5 QTLs of large effect are responsible for a large portion of the genetic variance in each of the traits measured. For example, 44.7% of the genetic variance in stem volume after 2 years of growth is controlled by just two QTLs. QTLs governing stem basal area were found clustered with QTLs for sylleptic branch leaf area, sharing similar chromosomal position and mode of action and suggesting a pleiotropic effect of QTLs ultimately responsible for stem diameter growth.
我们在一个由种间F1杂种（毛果杨×三角叶杨）杂交产生的杨树F2代中，对商业上重要的性状（茎生长和形态）以及一个适应性性状（春季叶萌发）进行了数量性状基因座（QTL）定位。在一个包含亲本、F1和F2代树木分株的重复无性系试验中，历时两年收集了表型数据。与数量性状遗传的简单多基因模型假设相反，1至5个具有较大效应的QTL对所测量的每个性状的大部分遗传变异负责。例如，生长两年后茎体积的44.7%的遗传变异仅由两个QTL控制。发现控制茎基部面积的QTL与萌条枝叶面积的QTL聚集在一起，共享相似的染色体位置和作用方式，这表明QTL最终对茎直径生长具有多效性作用。
