| Abstract Detail
Pollination Biology Jones, Laurah [1], Davis, Sandra L. [2]. Does the reproductive strategy of protandry in Saponaria officinalis prevent autogamy and avoid inbreeding depression? It has long been hypothesized that plant-mating systems that reduce the levels of self-fertilization have evolved due to selection for the avoidance of inbreeding depression and the accumulation of deleterious alleles. Mixed-mating systems (those in which both selfing and outcrossing occur), however, are more commonly observed than expected from theoretical models. Mixed mating systems may be advantageous in dichogamous species (those in which stamens and pistils mature at different times) as a mechanism for reproductive assurance if selfing takes place after opportunities for outcrossing has passed (delayed selfing). The current study examines the potential for mixed-mating in Saponaria officinalis, a protandrous perennial. Seed production of manipulated flowers was examined in five populations located in central Indiana. Results showed that selfing through autogamy may contribute little to reproduction: seed set in emasculated and control flowers did not differ significantly in any population and bagged flowers (which prevented insect pollination) produced significantly less (P=0.002) seed than the other two groups. There were no significant differences between seed production in geitonogamously pollinated versus outcrossed flowers (P< 0.001), indicating that the low level of autogamy is most likely due to protandry preventing the deposition of viable autonomous pollen onto receptive stigmas and not because self-pollination is incapable of producing viable seeds. Further tests were preformed to evaluate effect of self-pollination on offspring fitness. Seeds collected from the test populations were germinated in a controlled green house environment. Outcrossed seeds had higher weights than selfed seeds, but there did not seem to be any significant differences due to pollination type on germination date or seedling weight. In conclusion, protandry seems to be efficient at preventing self-fertilization in this species. However, some seed set is still possible through autogamy if insect visitation does not occur, but the seeds produced may be of lower quality.
Log in to add this item to your schedule
1 - University Of Indianapolis, Biology, 1400 E. Hanna ave, Indianapolis, IN, 46227, USA
2 - University of Indianapolis, Biology, 1400 E. Hanna Ave., Indianapolis, IN, 46227, USA
Keywords:
protandry
autogamy
inbreeding depression.
Presentation Type: Poster:Posters for Topics
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P75004
Abstract ID:1434 |
