Novel forms of mate recognition are often found in animals and plants with internal fertilization. Angiosperms (flowering plants) are a premier example because their unique reproductive tract (formed by the closed carpel) is the site where pollen competition and novel incompatibility systems are expressed before fertilization. Little is known of the origin and early evolution of these features. This project initiates a series of studies on mate recognition in the earliest divergent lineages of flowering plants (the so-called basal angiosperms). Controlled pollinations and timed collections will be used to provide precise description of developmental interactions of pollen, carpel and ovule, as well as relative rates and timing of the fertilization process. Genetic studies of mating systems and inbreeding history will provide insight into the effects of these interactions. An important result will be a comparative analyses of developmental traits. This and future studies will address the following questions:. (1) What forms of pollen-carpel-ovule interactions are present in early extant lineages of angiosperms? (2) How are they involved in mate recognition? (3) What kinds of developmental transformation best explain among-taxon patterns of reproductive diversification in early angiosperms? This study will contribute to two rapidly advancing areas of interest - plant reproduction and early angiosperm evolution.
The angiosperm stigma and transmitting tract have been seen as focal points of mate selection and rapid evolution, and the consequences of their origin and subsequent elaboration are of great interest to agronomists seeking to understand and manipulate breeding systems. Undergraduate and graduate students will be involved in studies that integrate mechanistic understanding of basic embryological processes with a broader perspective on evolutionary developmental diversity.
