Abstract Detail

Conservation Biology

Anderson, Gregory J. [1], Anderson, Mona [2], Ray, Gary [3], Sapio, David [4], Stanford, Alice [5].

Rare and unusual: Two dioecious solanums (S. polygamum, S. conocarpum) from the Caribbean in need of conservation.

Island plants are often, by geographic limitation, rare, and by virtue of relaxed, or different selection pressures, different. Two solanums from Caribbean, S. polygamum and S. conocarpum, are exemplars. Solanum polygamum, is very restricted (St. John and St. Thomas largely), and as is obvious from its name, has long been known to be reproductively unusual. The floral morphology also obviously reflects its dioecious condition. The male flowers are smaller, bear a very reduced pistil, and are often 4-merous. The pistil in the female flowers, which are sometimes 6-merous, are large, and the anthers small, and, in contrast to the majority of dioecious solanums, lack pollen. The very rare (limited to perhaps 250 plants on St. John) S. conocarpum is also, surprisingly dioecious, or sub-dioecious. This surprise comes from the fact that it resides in a group of solanums without much reproductive variation, and the similar-morphology pistillate (usually lack pollen, but bear styles exceeding the staminal column) and staminate (styles short to very reduced) flowers. Extensive field and greenhouse and lab studies demonstrate a male-biased sex ratio, distinctive morphological features, and unisexual performance - in terms of pollen production and fruit set. To be successful, conservation programs for rare species such as these have to be built around the knowledge of their reproductive biology.

Broader Impacts:
Reproductive modes are not always obvious: you can’t always recognize the reproductive system of plants by their gross morphology. Members of the genus Solanum have been particularly interesting because the dioecy manifest is most often cryptic. Thus, detailed studies of functional elements that help interpret morphological features can be exciting and rewarding. Evolution in isolation leads to some of the great wonders of the biological world, but also to species that do not necessarily compete well with hardened ‘world traveler’ - invasives. Thus, conservation plans, perhaps especially for island plants require deep knowledge of their biology, including pollination and reproductive biology, to be successful.

1 - University of Connecticut, Ecology & Evolutionary Biology, 75 North Eagleville Road, U-3043, Storrs, Connecticut, 062693043, USA
2 - University of Connecticut, Linguistics, Storrs, CT, 06269-3043
3 - University of Virgin Islands, Science and Mathematics, 2 John Brewers Bay, St. Thomas, VI, 00802, USA
4 - Virgin Islands National Park, 1300 Cruz Bay Creek, St. John, VI, 00830, USA
5 - University of Virgin Islands, College of Science and Mathematics, 2 John Brewers Bay, St. Thomas, VI, 00802, USA

Keywords:
dioecy
Reproductive biology
Conservation biology
island biology
Solanum
pollination
Caribbean.

Presentation Type: Oral Paper:Papers for Topics
Session: 47
Location: 551A/Convention Center
Date: Wednesday, August 4th, 2010
Time: 9:30 AM
Number: 47007
Abstract ID:31