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DYNAMICS OF GENE FLOW IN AN EXPERIMENTAL POPULATION OF CUCUMIS MELO (CUCURBITACEAE)
Author(s) -
Handel Steven N.
Publication year - 1982
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1982.tb13405.x
Subject(s) - cucumis , biology , gene flow , cucurbitaceae , botany , population , melon , horticulture , gene , genetic variation , genetics , sociology , demography
Gene flow in an experimental garden of Cucumis melo (Cucurbitaceae), the cultivated muskmelon, was measured by placing plants carrying a dominant gene (green cotyledons) in the center of an 18 × 18‐m field of recessive plants (yellow cotyledons). At the end of the growing season, all fruits were collected, and seeds planted for analysis of the progeny. The 123 fruits yielded 41,875 seedlings whose genotypes were recorded. Gene flow decreased with increasing distance from the central plot, while the variance increased. The decrease in frequency of the green gene did not follow a leptokurtic pattern over the distance measured, and there was a marked asymmetric and patchy pattern of gene flow in the field. The directionality contributed to a bimodal pattern of gene frequencies among fruits at the edges of the field, some fruits with no green seedlings, some with many. Bumblebee movements were recorded during 4,296 flower visits in an identically arrayed melon field. Bees usually moved to very nearby plants and visited only a few flowers on any one plant. This suggests that pollen carryover from the central patch out was quite high in the test garden. These findings show that local gene flow patterns in plant populations may be complex, and do not always follow regular and symmetrical models. The complex arrangement of progeny genotypes, when acted upon by local selective forces, may contribute to small‐scale differences often seen in plant populations.