Lack of floral nectar reduces self-pollination in a fly-pollinated orchid

0338686 - ÚVGZ 2010 RIV US eng J - Journal Article
Jersáková, Jana - Johnson, S.D.
Lack of floral nectar reduces self-pollination in a fly-pollinated orchid.
Oecologia. Roč. 147, - (2006), s. 60-68. ISSN 0029-8549. E-ISSN 1432-1939
Institutional research plan: CEZ:AV0Z60870520
Keywords : geitonogamy * inbreeding depression * pollen dispersal
Subject RIV: EF - Botanics
Impact factor: 3.333, year: 2006

One explanation for the widespread absence of floral nectar in many orchids is that it causes pollinators to visit fewer flowers on a plant, and thus reduces selfpollination. This, in turn, could increase fitness by reducing inbreeding depression in progeny and promoting pollen export. The few previous investigations of this hypothesis have all involved bee-pollinated orchids and some have given contradictory results. We studied the effects of adding artificial nectar (sucrose solution) to the spurs of a non-rewarding long-proboscid fly-pollinated orchid, Disa pulchra. Addition of nectar signifi- cantly increased the number of flowers probed by flies (2.6-fold), the time spent on a flower (5.4-fold), the number of pollinia removed per inflorescence (4.8-fold) and the proportion of removed pollen involved in selfpollination (3.5-fold). The level of self-pollination increased dramatically with the number of flowers probed by flies.
Permanent Link: http://hdl.handle.net/11104/0182400