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Pollination biology and breeding system of Phlox divaricata L. (Polemoniaceae).
Wiggam-Harper, Shelly*,1, Ferguson, Carolyn, 1 Kansas State University-Manhattan, Manhattan, KS
ABSTRACT- We studied the pollination biology and breeding system of Phlox divaricata at Konza Prairie Biological Station by addressing two questions: (1) What is the relative importance of diurnal, nocturnal and crepuscular pollinators for fruit and seed set, and (2) What is the level of self-incompatibility based on self-pollen hand-pollination and complete pollinator exclusion? Hemaris diffinis (Boisduval) and Autographa biloba (Stephens) had the highest visitation rates (48, 45% respectively) while Hemaris diffinis had the highest mean number of visits (9.5 flowers/plant) and the shortest mean time per visit (3.8 seconds) and A. biloba the lowest mean number of visits (5.5 flowers/plant) and the longest mean time per visit (14.2 seconds). Pollinator observation experiments resulted in the highest fruit set during the evening crepuscular time period (82%) and greatest seed set during the morning and afternoon diurnal time periods (80, 70% respectively). Plants that were hand-pollinated or left caged throughout their flowering period did set seed (16, 18% respectively), but it was significantly less than that of the natural population (80%), indicating a low level of selfing in a plant that was previously considered self-incompatible.
KEY WORDS: Phlox, pollination biology, breeding systems, floral emissions