Mating Patterns and Inbreeding Depression in Dimorphic Populations of Eichhornia paniculata (Pontederiaceae)

小行星9306473 一年生水生水葫芦的自然种群通常包含两个容易识别的遗传变体，其自受精率平均分别为0.8和0.2。 我们将利用这些人口来评估最近的几个理论预测的关键重要性，了解近交衰退和交配系统的变化的进化动力学。 我们将测量形态特异性水平的自体受精和雄性异交成功，以获得完整的信息形态特异性配子在这些自然种群中的传输。 这将提供一些关于增加自交率的花的形态如何影响配子传递的其他方面的第一信息。 我们将评估形态特异性近交衰退，看看控制交配系统的基因是否与负责近交衰退的适合度等位基因不平衡。 这种关联在许多最近的理论模型下是预期的，并且可以改变基于近交衰退的群体平均水平的预期。 然而，交配和健身等位基因之间的关联尚未被证明在任何自然群体的两性植物。 我们将对10年前首次检查的种群中的变形频率进行重新采样，以获得变形率随时间变化的稳定性信息。 以前的措施，在这些人群中的传播提供了一个快速下降的频率的变体与较低的自交率的预期。 如果形态频率没有改变，我们的传播和生存能力的措施应该阐明维持交配系统多态性的因素。 如果具有较低自交率的变体在下降，我们将获得一个在人类时间尺度上通过自然选择进化的异常有据可查的例子。 这些结果将为研究促进混合交配系统稳定性或不稳定性的因素以及自然群体中近交衰退的动态提供有用的见解。

9306473 Kohn Natural populations of the emergent-aquatic annual Eichhornia paniculata often contain two readily identifiable genetic morphs whose rates of self fertilization average 0.8 and 0.2, respectively. We will take advantage of these populations to evaluate several recent theoretical predications of critical importance for understanding the evolutionary dynamics of inbreeding depression and mating system change. We will measure morph-specific levels of self fertilization and male outcrossing success to obtain complete information on morph-specific gamete transmission in these natural populations. This will provide some of the first information on how a floral morphology that increases the selfing rate affects other aspects of gamete transmission. We will evaluate morph-specific inbreeding depression to see if genes that control the mating system are in disequilibrium with fitness alleles responsible for inbreeding depression. Such associations are expected under many recent theoretical models and can alter expectations based on population mean levels of inbreeding depression. However, associations between mating and fitness alleles have not as yet been demonstrated in any natural population of hermaphroditic plants. We will resample morph frequencies in populations first examined over 10 years ago to gain information on the stability of morph ratios over time. Previous measures of transmission in these populations provided an expectation of rapid decline in the frequency of the morph with the lower selfing rate. If morph frequencies have not changed, our measures of transmission and viability should shed light on factors maintaining mating system polymorphism. If the morph with the lower selfing rate is in decline, we will gain an unusually well-documented example of evolution by natural selection over a human time scale. The results will provide useful insights into factors promoting stability or instability of mixed mating systems and t he dynamics of inbreeding depression in natural populations.***