Genetic Architecture and Introgression in Louisiana Iris Hybrid Zones

本文将遗传学和生态学相结合，研究路易斯安那州鸢尾（Iris fulva）和短尾鸢尾（I. brevicaulis）之间的自然基因交换。我们将测试：i)影响不同微生境中生长、存活和繁殖的遗传元素的数量和基因组位置；Ii)不同环境下不同基因型植物的花区和微生境性状对其育性和繁殖力的相对贡献；3)花性状遗传因子、雄性育性和微生境关联对富尔花与短叶花基因自然转移的影响。我们提出的研究对农业和保护生物学也有影响。从历史上看，作物改良是通过我们正在研究的过程来完成的——渐渗杂交（即杂交形式之间的基因交换）。因此，这项工作将辨别影响作物改良的一些遗传和生态性状。此外，我们的研究将回答有关转基因（GM）作物意外与其野生近缘种交换基因的可能性的问题。这些研究在确定如何管理稀有物种方面至少有两个应用。首先，环境变化导致稀有物种通过与更常见和繁殖形式的自然杂交而消失（例如，家养狗与野生犬科动物杂交）。其次，人们担心转基因物种会与野生近缘种杂交，产生能够竞争性地取代野生物种的杂交品种。我们的研究将提供数据，以确定如何最好地防止这两种情况的发生。

The studies described in this proposal integrate genetics and ecology to investigate natural gene exchange between the Louisiana Iris species, Iris fulva and I. brevicaulis. We will test for: i) the number and genomic location of genetic elements that affect growth, survivorship and reproduction in different microhabitats; ii) the relative contribution of floral and microhabitat characters on the fertility and fecundity of different genotypes in different environments; and iii) the effect of genetic elements for floral traits, male fertility and microhabitat associations on the natural transfer of genes between I. fulva and I. brevicaulis.Our proposed research also has implications for both agriculture and conservation biology. Crop improvement has historically been accomplished using the process we are studying - introgressive hybridization (i.e., the exchange of genes between hybridizing forms). This work will thus discern some of the genetic and ecological traits that affect crop improvement. Further, our studies will answer questions concerning the likelihood that genetically modified (GM) crops will accidentally exchange genes with their wild relatives. These studies also have at least two applications for determining how to manage rare species. First, environmental changes are resulting in the loss of rare species through natural hybridization with more common and prolific forms (e.g., wild canids by domestic dogs). Second, there is concern that GM species will hybridize with wild relatives, producing hybrid types capable of competitively replacing the wild species. Our studies will provide data to determine how best to prevent both of these occurrences.