Pollination limitation to reproductive success in the Missouri evening primrose, Oenothera macrocarpa (Onagraceae)

Citation
Jm. Moody-weis et Js. Heywood, Pollination limitation to reproductive success in the Missouri evening primrose, Oenothera macrocarpa (Onagraceae), AM J BOTANY, 88(9), 2001, pp. 1615-1622
Citations number
67
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences
Journal title
AMERICAN JOURNAL OF BOTANY
ISSN journal
0002-9122 → ACNP
Volume
88
Issue
9
Year of publication
2001
Pages
1615 - 1622
Database
ISI
SICI code
0002-9122(200109)88:9<1615:PLTRSI>2.0.ZU;2-2
Abstract
Habitat fragmentation may result in plant populations that are less attract ive to pollinators and thus susceptible to reduced reproductive output due to pollination limitation. Pollination limitation was investigated in three Missouri populations of Oenothera macrocarpa, a hawk-moth-pollinated, pere nnial herb. The populations represented extremes in size and habitat qualit y. Following supplemental pollination, mean fertilization success (proporti on of ovules fertilized) across populations increased from 24.3 to 44.8% an d mean seed set (proportion of ovules that matured into seed) increased fro m 14.7 to 27.9%. These increases were statistically significant in two of t he three populations. Failure to achieve 100% fertilization and seed set fo llowing supplementation indicates that other factors, in addition to pollin ation, were limiting to female reproductive success. Fruit set was pollinat ion limited in only one population. Fruits matured with as few as one seed, suggesting that fruit set was not resource limited. The degree of pollinat ion limitation was greatest in the most disturbed population. The populatio n located in the highest-quality habitat was not significantly pollination limited. This suggests that pollination limitation is occurring, at least i n part, because of reduced pollinator activity in degraded habitats.