Lambrides C J, Godwin I D, Lawn R J, Imrie B C
University of Queensland School of Land and Food Sciences, St. Lucia, Brisbane 4072, Australia.
J Hered. 2004 Nov-Dec;95(6):532-5. doi: 10.1093/jhered/esh078.
Genetic segregation experiments with plant species are commonly used for understanding the inheritance of traits. A basic assumption in these experiments is that each gamete developed from megasporogenesis has an equal chance of fusing with a gamete developed from microsporogenesis, and every zygote formed has an equal chance of survival. If gametic and/or zygotic selection occurs whereby certain gametes or zygotic combinations have a reduced chance of survival, progeny distributions are skewed and are said to exhibit segregation distortion. In this study, inheritance data are presented for the trait seed testa color segregating in large populations (more than 200 individuals) derived from closely related mungbean (Vigna radiata L. Wilcek) taxa. Segregation ratios suggested complex inheritance, including dominant and recessive epistasis. However, this genetic model was rejected in favor of a single-gene model based on evidence of segregation distortion provided by molecular marker data. The segregation distortion occurred after each generation of self-pollination from F1 thru F7 resulting in F7 phenotypic frequencies of 151:56 instead of the expected 103.5:103.5. This study highlights the value of molecular markers for understanding the inheritance of a simply inherited trait influenced by segregation distortion.
植物物种的遗传分离实验通常用于了解性状的遗传。这些实验的一个基本假设是，由大孢子发生发育而来的每个配子与由小孢子发生发育而来的配子融合的机会均等，并且形成的每个合子存活的机会均等。如果发生配子和/或合子选择，即某些配子或合子组合的存活机会减少，后代分布就会倾斜，据说表现出分离畸变。在本研究中，给出了来自近缘绿豆（Vigna radiata L. Wilcek）分类群的大群体（超过200个个体）中种子种皮颜色性状的遗传数据。分离比例表明存在复杂遗传，包括显性和隐性上位性。然而，基于分子标记数据提供的分离畸变证据，该遗传模型被否定，转而支持单基因模型。从F1到F7，每一代自花授粉后都发生分离畸变，导致F7表型频率为151:56，而不是预期的103.5:103.5。本研究强调了分子标记对于理解受分离畸变影响的简单遗传性状遗传的价值。
