Zhou Wei, Barrett Spencer C H, Wang Hong, Li De-Zhu
Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan, 650201, China.
Plant Germplasm and Genomics Center, Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, Yunnan, 650201, China.
New Phytol. 2015 Jun;206(4):1503-12. doi: 10.1111/nph.13326. Epub 2015 Feb 9.
Mating patterns in heterostylous species with intramorph compatibility have the potential to deviate from symmetrical disassortative mating owing to ecological and reproductive factors influencing pollen dispersal. Here, we investigate potential and realized patterns of mating in distylous Luculia pinceana (Rubiaceae), a species with intramorph compatibility. Our analysis provides an opportunity to test Darwin's hypothesis that reciprocal herkogamy promotes disassortative pollen transfer. We combined measurements of sex-organ reciprocity and pollen production to predict potential pollen transfer and mating patterns in a population from SW China. Marker-based paternity analysis was then used to estimate realized patterns of disassortative and assortative mating at the individual and floral morph levels. Both potential and realized mating patterns indicated a significant component of disassortative mating, satisfying theoretical conditions for the maintenance of floral dimorphism. Levels of assortative mating (37.7%) were significantly lower than disassortative mating (62.3%), but numerous offspring resulting from intramorph mating were detected in the majority of maternal seed families in both floral morphs. Our results provide empirical support for Darwin's cross-promotion hypothesis on the function of reciprocal herkogamy, but indicate that in most heterostylous species strong diallelic incompatibility may be a general requirement for complete disassortative mating.
由于影响花粉传播的生态和繁殖因素，具有同型内交配相容性的异型花柱物种的交配模式有可能偏离对称的异交交配。在此，我们研究了异型花柱的滇丁香（茜草科）的潜在交配模式和实际交配模式，该物种具有同型内交配相容性。我们的分析提供了一个机会来检验达尔文的假说，即交互异位促进异交花粉传递。我们结合了性器官交互性和花粉产量的测量，以预测中国西南部一个种群中的潜在花粉传递和交配模式。然后，基于标记的父本分析被用于估计个体和花型水平上的异交和同交交配的实际模式。潜在和实际交配模式均表明异交交配占显著比例，满足维持花二型性的理论条件。同交交配水平（37.7%）显著低于异交交配水平（62.3%），但在两个花型的大多数母本种子家族中都检测到了大量同型内交配产生的后代。我们的结果为达尔文关于交互异位功能的交叉促进假说提供了实证支持，但表明在大多数异型花柱物种中，强大的双等位基因不相容性可能是完全异交交配的普遍要求。
