Effective Pollen Dispersal in a Natural Population of Asclepias exaltata: The Influence of Pollinator Behavior, Genetic Similarity, and Mating Success

1991 ◽  
Vol 138 (5) ◽  
pp. 1239-1249 ◽  
Author(s):  
Steven B. Broyles ◽  
Robert Wyatt
Keyword(s):  
Natural Population ◽  
Mating Success ◽  
Genetic Similarity ◽  
Pollen Dispersal ◽  
Behavior Genetic ◽  
Pollinator Behavior

Pollen-mediated gene flow in a small, fragmented natural population of Fagus crenata

2007 ◽  
Vol 85 (4) ◽  
pp. 404-413 ◽  
Author(s):  
So Hanaoka ◽  
Jungo Yuzurihara ◽  
Yamashita Asuka ◽  
Nobuhiro Tomaru ◽  
Yoshihiko Tsumura ◽  
...  
Keyword(s):  
Gene Flow ◽  
Maximum Likelihood ◽  
Natural Population ◽  
Maximum Likelihood Method ◽  
Pollen Dispersal ◽  
Fagus Crenata ◽  
Likelihood Method ◽  
Dispersal Patterns ◽  
Breast Height ◽  
Fagus Crenata Blume

Pollen-mediated gene flow was analyzed in a small, fragmented, natural population of Fagus crenata Blume by surveying five microsatellite markers in seedlings derived from open-pollinated crosses. Paternity of 162 seedlings derived from two maternal trees was assigned by the maximum-likelihood method using CERVUS 2.0, and pollen dispersal patterns within the study site were determined. Most of the trees within the site sired seeds, although we found evidence of limited pollen-mediated gene flow from outside the stand; 92% of the matings that generated the seedlings occurred between trees within the population, and 8% of the matings were mediated by pollen derived from trees located outside the study site. Although the pollen-mediated gene flow within the site was not strongly limited, mating frequencies of paternal trees were found to be weakly negatively correlated with their distance from the mother trees, positively correlated with their stem diameter at breast height, and uncorrelated with their relatedness to the mother trees.

scholarly journals Doing the twist: a test of Darwin's cross-pollination hypothesis for pollinarium reconfiguration

2005 ◽  
Vol 2 (1) ◽  
pp. 65-68 ◽  
Author(s):  
Craig I Peter ◽  
Steven D Johnson
Keyword(s):  
Inbreeding Depression ◽  
Mating Success ◽  
Positive Relationship ◽  
Pollen Dispersal ◽  
Strong Support ◽  
Cross Pollination ◽  
Self Pollination ◽  
Strong Positive Relationship ◽  
Mating Opportunities

Mating success in plants depends largely on the efficiency of pollen dispersal. For hermaphrodite plants, self-pollination, either within or among flowers, can reduce mating opportunities because of pollen and ovule discounting and inbreeding depression. Self-pollination may be particularly detrimental in plants such as orchids and asclepiads that package each flower's pollen into one or more pollinia which, together with accessory structures, comprise a pollinarium. Darwin proposed that physical reconfiguration of pollinaria serves as a mechanism for reducing the likelihood of self-pollination. To be effective, the time taken for pollinarium reconfiguration would need to exceed that spent by a pollinator on a plant. We investigated pollinarium reconfiguration (including pollinarium bending, pollinium shrinking and anther cap retention) in 19 species and found a strong positive relationship between reconfiguration time and the duration of pollinator visits. Reconfiguration times were also consistently longer than pollinator visit times. These results provide strong support for Darwin's idea that this mechanism promotes cross-pollination.

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