title: Patterns of pollen flow in a dense population of the insect-pollinated canopy tree species Castanopsis sieboldii.
abstract: Insect pollinations of tree species with high-density populations have rarely been studied. Since the density of adults can affect effective pollen dispersal, short-distance pollination, even by insects, may frequently occur in high-density populations. To test this prediction, we investigated pollination patterns in a high-density population of the insect-pollinated canopy tree species Castanopsis sieboldii by paternity analysis using genotypes at 8 microsatellite loci of 145 adult trees and 439 seeds from 11 seed parents in a 4-ha plot. We then explored their genetic effects on the population by calculating other population genetics parameters. Although C. sieboldii has high potential for long-distance dispersal of pollen (as indicated by a fat-tailed dispersal kernel), the cumulative pollination at the local scale was spatially limited and strongly dependent on the distance between parents due to the high density of adults. Genetic diversity estimates for pollen pools accepted by each seed parent converged on a maximum as the effective number of pollen parents increased. The genetic diversity of pollen pool bulked over all the seed parents from inside the plot did not differ from that of the total pollen pools. Therefore, although pollen flow from distant pollen parents may help to maintain the genetic diversity of offspring, pollen parents neighboring seed parents may be the main contributors to the genetic diversity of the offspring at the seed stage.
authors.affiliation: atsunakanishi@yahoo.co.jp
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nakanishi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yoshimaru
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Tomaru
authors.forename: Masahiro
authors.initials: M
authors.lastname: Miura
authors.forename: Tohru
authors.initials: T
authors.lastname: Manabe
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Yamamoto
mesh_terms: D000818:Animals; D029962:Fagaceae / Q000235:genetics*; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D007313:Insecta / Q000502:physiology*; D018895:Microsatellite Repeats; D011058:Pollen / Q000235:genetics; D054817:Pollination / Q000235:genetics*; D011156:Population Density