Tiffin P, Olson M S, Moyle L C
Department of Ecology and Evolutionary Biology, University of California Irvine, 92697, USA.
Proc Biol Sci. 2001 Apr 22;268(1469):861-7. doi: 10.1098/rspb.2000.1578.
Patterns of reproductive isolation between species may provide insight into the mechanisms and evolution of barriers to interspecific gene exchange. We used data from published interspecific hybridization experiments from 14 genera of angiosperms in order to test for the presence of asymmetrical barriers to gene exchange. Reproductive isolation was examined at three life-history stages: the ability of interspecific crosses to produce seeds, the viability of F1 hybrids, and the fertility of F1 hybrids. Statistically significant asymmetries in the strength of reproductive isolation between species were detected in all genera and at each of the three life-history stages. Asymmetries in seed production may be caused by a variety of mechanisms including differences in stigma/style lengths, self compatibility and differential fruit abortion. Asymmetries in post-zygotic isolation are probably caused by nuclear-cytoplasmic interactions. Asymmetrical reproductive isolation between plant taxa may have important implications for the dynamics of hybrid zones, the direction of genetic introgression and the probability of reinforcement.
物种间生殖隔离模式有助于深入了解种间基因交流障碍的机制和进化过程。我们利用已发表的来自14个被子植物属的种间杂交实验数据，来检测基因交流中不对称障碍的存在情况。在三个生活史阶段对生殖隔离进行了研究：种间杂交产生种子的能力、F1杂种的活力以及F1杂种的育性。在所有属以及三个生活史阶段的每个阶段，均检测到物种间生殖隔离强度存在统计学上的显著不对称性。种子产量的不对称性可能由多种机制引起，包括柱头/花柱长度差异、自交亲和性以及果实选择性败育。合子后隔离的不对称性可能是由核质相互作用导致的。植物类群间的不对称生殖隔离可能对杂交区动态、基因渐渗方向以及强化概率具有重要影响。
