Pollinator limitaton in a deceptive orchid, Pogonia japonica, on a floating peat mat

Abstract

Deceptive orchid species that offer no floral rewards to pollinators often experience pollinator limitation because they. The breeding system and fruit set were investigated in order to examine pollinator limitation for a population of a deceptive orchid, Pogonia japonica, on a floating peat mat in Mizorogaike Pond, western Japan. Fruit sets for outcross‐pollinated, self‐pollinated and pollinator‐excluded flowers were 75%, 80%, and 0%, respectively. Thus, this species was self‐compatible but neither autogamous nor apogamous. The fruit set for open‐pollinated flowers was 22.9% and 17.4% in 1994 and 1995, suggesting that pollinator limitation did occur in the field. Larger flowers were more likely to develop into fruit than smaller ones in open pollination (36%vs 8%). Thus, flower size seems to affect fruiting of this species. No effective visits by major pollinators such as bees, which could carry pollinia, were observed during 16.5 h of observation during daytime. Instead, thrips were often found moving on gynostemium or pollinia and circumstantial evidence that suggests thrips may partly transfer pollen in pieces out of a granular pollinium of P. japonica was obtained. Pogonia japonica should come to use thrips as a pollinator to supplement low fruit set under limited flower visitation by major pollinators.

ISSR and ITS comparisons among <i>Pogonia japonica</i>, <i>P. minor</i> and <i>P.</i> ‘Miyamatokisou’ <i>nomen nudum</i>

“…Thus, the members of Pogonia could perform naturally as well as artificially interspecific hybrids (Thien and Marcks 1972;Tanaka et al 1996;Matsui et al, 2001;Takahashi and Kondo 2004). Additionally, P. japonica shows self-compatibility but no self-pollination as well as parthenogenesis (Matsui et al 2001), while P. minor shows auto-self-pollination and their seeds are produced by self-fertilization (Suetsugu 2015). Moreover, P. minor has the characteristics of non-fully-opened flower and self-pollination, and thus, is the speces as a sexually well-isolated species.…”

Effect of floral organ sizes on female reproductive success inErythronium japonicum (Liliaceae)

“…The difference might be caused by differences in pollinator activity between sites. Larger individuals tend to produce larger flowers in some flowering plants (Matsui et al, 2001). Thus, there is another possibility that larger flowers have more resource so that they can produce more seeds in E. japonica, though the idea cannot explain the difference in fruiting pattern between the Ogawa Forest Reserve and Mt.…”

Notes on fine-scale spatial distribution of three Cephalanthera species (Orchidaceae) that grow in sympatry in Korea: Implications for maintenance of species boundaries

“…To determine local heterogeneity in fruit set within and among patches in HEA and HED populations surveyed in 2002 and 2003, we used G statistic for the log-likelihood ratio goodness of fit test (e.g., Matsui et al, 2001). Type I error was adjusted for multiple tests by Šidák (1967) method conducted within and among patches ( = 0.0015 and = 0.0127, respectively).…”

“…Owing to differences in ecological determinants in space, levels of fruit set usually vary among populations in a given species (Bino et al, 1982;Ackerman et al, 1997;Matsui et al, 2001;Ehlers et al, 2002;Chung and Chung, 2005;Jacquemyn and Brys, 2010). However, fruit set in some orchid populations is usually consistent from year to year (Nilsson, 1983;Gill, 1989;Primack and Hall, 1990;Ackerman and Moya, 1996;Tremblay et al, 2005), whereas the others revealed variation in fruit set over time due to environmental perturbations (Nilsson, 1983(Nilsson, , 1984Alexandersson and Ågren, 1996;Jacquemyn and Brys, 2010).…”