Pollination Efficiencies of Insects Visiting Magnolia obovata, as Determined by Single-Pollen Genotyping

Variation in Pollen-Donor Composition among Pollinators in an Entomophilous Tree Species, Castanea crenata, Revealed by Single-Pollen Genotyping

“…Recent molecular studies have demonstrated that insect pollinators disperse pollen across long distances (e.g., 242–16000 m) in several tree species [ 17 , 41 , 59 , 60 ]. Pollen-dispersal distances strongly affect plant fitness, particularly when closely related individual plants are spatially aggregated (i.e., have a fine-scale genetic structure) because of biparental inbreeding depression [ 20 – 23 ].…”

“…To compare the pollen-dispersal distances of outcross-pollen grains among insect groups, we distinguished between the outcross-pollen grains originating from inside and outside the study plot and then compared the frequencies of pollen dispersal from outside the study plot among insect groups using a chi-squared test followed by Ryan’s post hoc test. The pollen-dispersal patterns of insect-pollinated tree species shows a long-tailed distribution (e.g., [ 17 , 59 , 60 ]), and this dispersal pattern was observed in C . crenata [ 41 ]; thus, we considered pollen dispersal from outside the study plot as longer-distance dispersal than that from inside of the plot.…”

“…For example, beetles of the subfamily Cetoniinae ( Protaetia cataphracta and Eucetonia pilifera ) carried greater amounts of outcross pollen much farther (maximum distance = 1100 m) than bumblebees ( Bombus ardens and B . diversus ) and small beetles ( Arthromacra sumptuosa ) in a low-density population of the hermaphrodite tree Magnolia obovata [ 16 , 17 ]. These facts suggest that pollen-dispersal patterns strongly affect plant fitness, particularly when closely related individual plants are distributed in a spatially aggregated manner (i.e., a fine-scale genetic structure) and potentially subject to biparental inbreeding depression [ 20 – 23 ].…”

“…In this study, we evaluated the pollen-donor composition (i.e., self-pollen and outcross-pollen from near and distant donors) on individual pollinators that visited a deciduous broadleaf tree species, Castanea crenata , by DNA amplification and paternity analysis based on microsatellite genotyping of individual pollen grains. DNA amplification of pollen grains or pollinaria (pollen packages) found on a pollinator has been reported in several recent studies using amplified fragment-length polymorphisms (AFLP; [ 31 ]), chloroplast DNA [ 32 ], a nuclear ribosomal internal transcribed spacer (ITS; [ 33 – 35 ], and nuclear microsatellites [ 16 , 17 , 36 – 39 ]. Multiplex polymerase chain reaction (PCR) techniques that amplify nuclear microsatellite regions in a single reaction allow for easy paternity analysis from a single pollen grain [ 16 , 17 , 38 – 41 ].…”