Selective Consequences of Natural Hybridization in Louisiana Irises

9703853 阿诺德 我们将测试自然选择的作用，在生产和生存的混合路易斯安那州鸢尾。 我们的分析将包括实验杂交内和之间的物种鸢尾和鸢尾brevicaulis产生各种杂交和亲本种子。 然后将这些种子放入温室和自然环境中。 然后将监测和比较杂交个体和亲本个体的发芽、存活、生长至成熟和生殖能力。 杂交植物将使用许多分子（即，DNA）标记。 因此，这些分析将允许父母和杂种植物的适合度的估计。 这些估计，然后可以用来预测长期的影响，不同的虹膜物种之间的自然杂交可能对遗传多样性和进化的植物物种复杂。 属于不同属、种或亚种的个体之间的自然杂交已被认为是许多植物进化中的一个根本性的重要过程。 事实上，据估计，超过一半的开花植物物种（即，被子植物）起源于古代或更近的杂交事件。 此外，最近开始认识到，自然杂交和随后的杂交群体之间的基因交换对动物也同样重要。 我们对路易斯安那鸢尾花的研究将使我们能够详细考察这一迷人而重要的过程。 特别是，这些研究将有助于确定自然选择在决定自然杂交的进化后果中的作用。

9703853 Arnold We will test the role of natural selection in the production and survivorship of hybrid Louisiana irises. Our analyses will include experimental crosses within and between the species Iris fulva and Iris brevicaulis to produce various hybrid and parental seeds. These seeds will then be placed into both greenhouse and natural environments. The germination, survivorship, growth to maturity and reproductive capacity of the hybrid and parental individuals will then be monitored and compared. The hybrid plants will be assigned to specific categories using numerous molecular (i.e., DNA) markers. These analyses will thus allow an estimate of the fitness of both parentaland hybrid plants. These estimates can then be used to predict the long-term effects that natural hybridization between different iris species may have on the genetic diversity and evolution of this plant species complex. Natural hybridization between individuals belonging to different genera, species or subspecies has been recognized as a fundamentally important process in the evolution of many plants. Indeed, it has been estimated that over half of all flowering plant species (i.e., Angiosperms) have originated from ancient or more recent hybridization events. Furthermore, it has recently begun to be appreciated that natural hybridization and subsequent exchange of genes between the hybridizing groups can be equally important for animals as well. Our studies of the Louisiana irises will allow a detailed examination of this fascinating and important process. In particular, these studies will help define the role of natural selection in determining the evolutionary consequences of natural hybridization.