You are here:
Variation in pollen competitive ability in diverse maize lines
Citation:
FOWLER, J., Z. Vejlupkova, A. Qu, AND L. S. WATRUD. Variation in pollen competitive ability in diverse maize lines. Presented at 50th Maize Genetics Conference, Washington, DC, February 27 - March 02, 2008.
Impact/Purpose:
Although pollen occupies a small fraction of the angiosperm life cycle, it is of interest for both basic and applied scientific reasons.
Description:
Although pollen occupies a small fraction of the angiosperm life cycle, it is of interest for both basic and applied scientific reasons. Seed production depends on a functional male gametophyte achieving fertilization following pollination. Pollen also serves as a vector for gene flow between plant populations. Recently, propagation of transgenic plant cultivars has raised concerns about viable pollen dispersal and its role in introducing transgenes into non-transgenic populations. We are interested in understanding the genetic basis for pollen fitness, and are developing methods to predict whether certain plant cultivars or genotypes pose greater particular risks for transgene escape via pollen-mediate gene flow than others. As a first step in investigating natural variation that affects pollen fitness, we are measuring pollen competitive ability (PCA) in a set of maize lines recommended by the Panzea project to maximize diversity. We use a pollen-mising method employed previously by Sari-Gorla, Ottaviano, Pé and co-workers and implement it in a Latin Square experimental design. With each tested on at least four days, we found significant day-to-day differences in PCA. Despite this, a range of significant differences in PCA (relative to the reference W22-R line) among maize inbred was identified, up to almost 4-fold between MS71 and P39. In addition, the two hybrids (B73xMo17 and T232xCM37) tested in our initial round of experiments produced pollen that was more competitive than the inbred parents. These results are consistent with earlier work demonstrating correlation between sporophytic vigor and pollen fitness (reviewed in Ottaviano & Mulcahy 1989). Data from a second round of experiments, incorporating additional inbred lines and hybrids is being analyzed and will be presented.