Leibniz Institute of Plant Genetics and Crop Plant Research, Corrensstrasse 3, Gatersleben, Germany.
Theor Appl Genet. 2011 May;122(8):1631-9. doi: 10.1007/s00122-011-1560-5. Epub 2011 Mar 1.
Knowledge of mating systems is required in order to understand the genetic composition and evolutionary potential of plant populations. Outcrossing in a population may co-vary with the ecological and historical factors influencing it. However, literature on the outcrossing rate is limited in terms of wild sorghum species coverage and eco-geographic reference. This study investigated the outcrossing rates in wild sorghum populations from different ecological conditions of Kenya. Twelve wild sorghum populations were collected in four sorghum growing regions. Twenty-four individuals per population were genotyped using six polymorphic simple sequence repeat (SSR) markers to compute their indirect equilibrium estimates of outcrossing rate as well as population structure. In addition, the 12 populations were planted in a field in a randomised block design with five replications. Their progeny (250 individuals per population) were genotyped with the six SSR markers to estimate multi-locus outcrossing rates. Equilibrium estimates of outcrossing rates ranged from 7.0 to 75.0%, while multi-locus outcrossing rates (t (m)) ranged from 8.9 to 70.0% with a mean of 49.7%, indicating that wild sorghum exhibits a mixed mating system. The wide range of estimated outcrossing rates in wild sorghum populations indicate that environmental conditions may exist under which fitness is favoured by outcrossing and others under which selfing is more advantageous. The genetic structure of the populations studied is concordant with that expected for a species displaying mixed mating system.
为了理解植物种群的遗传组成和进化潜力，需要了解交配系统的知识。种群中的异交可能与影响它的生态和历史因素共同变化。然而，关于异交率的文献在野生高粱物种覆盖范围和生态地理参考方面有限。本研究调查了肯尼亚不同生态条件下野生高粱种群的异交率。在四个高粱种植区收集了 12 个野生高粱种群。每个种群采集 24 个个体，使用 6 个多态性简单重复序列（SSR）标记进行基因型分析，以计算其间接平衡异交率估计值和种群结构。此外，将 12 个种群以随机区组设计种植在一个田间，设有 5 个重复。用 6 个 SSR 标记对其后代（每个种群 250 个个体）进行基因型分析，以估计多座位异交率。异交率的平衡估计值范围为 7.0 至 75.0%，而多座位异交率（t (m)）范围为 8.9 至 70.0%，平均值为 49.7%，表明野生高粱表现出混合交配系统。野生高粱种群中估计的异交率范围很广，这表明在某些环境条件下，异交有利于适应性，而在其他环境条件下，自交更为有利。研究种群的遗传结构与表现出混合交配系统的物种的预期结构一致。
