THE DEVELOPMENT AND APPLICATION OF A REFINED METHOD FOR ESTIMATING GENE FLOW FROM ANGIOSPERM PATERNITY ANALYSIS

Area of Science:

• Population genetics
• Ecology
• Evolutionary biology

Background:

• Gene flow significantly influences population genetic structure.
• Empirical quantification of gene flow, particularly by pollen, remains challenging.
• Paternity-exclusion analysis offers a tool for assessing pollen-mediated gene flow.

Purpose of the Study:

• To develop and illustrate a general Monte Carlo method for estimating gene flow by pollen using paternity-exclusion analysis.
• To estimate the proportion of seeds fathered by foreign pollen in wild radish populations.
• To determine the number of foreign gametes received by individuals within these populations.

Main Methods:

• Application of paternity-exclusion analysis to assess parentage of seeds.
• Development of a general Monte Carlo method for approximate maximum-likelihood estimation of gene flow.
• Estimation of foreign gamete contribution to individuals within the study populations.

Main Results:

• An estimated 7% and 6.3% of seeds in two isolated wild radish populations originated from foreign pollen.
• Confidence intervals for foreign pollen contribution were 5.0-9.0% and 5.4-7.2%, respectively.
• No correlation was found between foreign gamete reception and reproductive traits or genetic markers.

Conclusions:

• The developed Monte Carlo method provides a robust approach for estimating gene flow by pollen.
• Wild radish populations exhibit measurable levels of gene flow from surrounding populations despite geographical isolation.
• Reproductive and genetic characteristics do not appear to predict the level of foreign gamete acquisition.