WHOLE- AND PART-FLOWER SELF-POLLINATION IN GLYCINE CLANDESTINA AND G. ARGYREA AND THE EVOLUTION OF AUTOGAMY

Area of Science:

• Plant reproductive biology
• Evolutionary ecology
• Population genetics

Background:

• Self-fertilization rates are crucial for understanding plant mating systems and evolution.
• Distinguishing between whole-flower and part-flower selfing provides a more nuanced view of reproductive strategies.
• Environmental factors, particularly pollinator availability, can significantly influence mating system dynamics.

Purpose of the Study:

• To develop and apply a model that partitions overall self-fertilization into whole-flower and part-flower components.
• To investigate mating system parameters in two Glycine species across different populations and elevations.
• To explore the role of environmental variability and pollinator activity in driving selfing rates.

Main Methods:

• Development of a novel mating system model using progeny from separate fruits as observational units.
• Estimation of mating system parameters using marker genotypes from chasmogamous fruits.
• Application of Monte Carlo simulations to assess potential biases in parameter estimation.

Main Results:

• A subalpine population of Glycine clandestina exhibited significant whole-flower selfing.
• Lower elevation G. clandestina and subtropical G. argyrea populations did not show significant whole-flower selfing.
• Environmental conditions and pollinator activity variability are proposed as key factors influencing these differences.

Conclusions:

• Environmental conditions, especially those limiting insect-mediated pollination, can induce whole-flower selfing.
• Induced selfing can lead to the selection of intermediate self-pollination levels (between 0 and 1).
• Ignoring correlations between whole- and part-flower selfing events can bias mating system estimates.