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The genetic basis of floral variation in Senecio jacobaea (Asteraceae)

Andersson, Stefan LU (2001) In Journal of Heredity 92(5). p.409-414
Abstract
The self-incompatible composite Senecio Jacobaea (ragwort) exhibits geographic variation in the frequency of rayed and discoid (rayless) individuals. Hybrid progenies from within- and between-morph crosses were established in a seminatural (garden) environment to determine whether patterns of segregation conform to single-gene predictions (as found in other Senecio species), whether the direction of dominance is conducive to rapid evolutionary change in ray morphology, and whether geographically distant populations of the discoid morph utilize the same or different genes to suppress ray development. Data from segregating F-2 and BC families were consistent with a genetic model involving one major locus and an unknown number of modifiers.... (More)
The self-incompatible composite Senecio Jacobaea (ragwort) exhibits geographic variation in the frequency of rayed and discoid (rayless) individuals. Hybrid progenies from within- and between-morph crosses were established in a seminatural (garden) environment to determine whether patterns of segregation conform to single-gene predictions (as found in other Senecio species), whether the direction of dominance is conducive to rapid evolutionary change in ray morphology, and whether geographically distant populations of the discoid morph utilize the same or different genes to suppress ray development. Data from segregating F-2 and BC families were consistent with a genetic model involving one major locus and an unknown number of modifiers. Analysis of F-1 progenies from different intermorph crosses using the same rayed plant as a seed parent revealed a variable and incomplete pattern of dominance, with a trend toward partial dominance in some crosses. Hybridizations between discoid populations produced a few rayed progeny (4%), but there was no tendency for the frequency of rayed progeny to increase with the geographic distance separating the parent populations. Results of this study indicate that major mutations have been important for the evolution of discoid populations of ragwort, that ray-suppressing mutations should be directly available to selection in most populations, and that the suppression of rays is conditioned by the same or similar gene(s) in Atlantic and Baltic populations of the discoid taxon. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Heredity
volume
92
issue
5
pages
409 - 414
publisher
Oxford University Press
external identifiers
  • scopus:0035673812
ISSN
0022-1503
DOI
10.1093/jhered/92.5.409
language
English
LU publication?
yes
id
0ad22a68-d173-4933-ab02-d13b4783e2f9 (old id 147219)
date added to LUP
2007-07-02 08:00:22
date last changed
2018-05-29 10:20:37
@article{0ad22a68-d173-4933-ab02-d13b4783e2f9,
  abstract     = {The self-incompatible composite Senecio Jacobaea (ragwort) exhibits geographic variation in the frequency of rayed and discoid (rayless) individuals. Hybrid progenies from within- and between-morph crosses were established in a seminatural (garden) environment to determine whether patterns of segregation conform to single-gene predictions (as found in other Senecio species), whether the direction of dominance is conducive to rapid evolutionary change in ray morphology, and whether geographically distant populations of the discoid morph utilize the same or different genes to suppress ray development. Data from segregating F-2 and BC families were consistent with a genetic model involving one major locus and an unknown number of modifiers. Analysis of F-1 progenies from different intermorph crosses using the same rayed plant as a seed parent revealed a variable and incomplete pattern of dominance, with a trend toward partial dominance in some crosses. Hybridizations between discoid populations produced a few rayed progeny (4%), but there was no tendency for the frequency of rayed progeny to increase with the geographic distance separating the parent populations. Results of this study indicate that major mutations have been important for the evolution of discoid populations of ragwort, that ray-suppressing mutations should be directly available to selection in most populations, and that the suppression of rays is conditioned by the same or similar gene(s) in Atlantic and Baltic populations of the discoid taxon.},
  author       = {Andersson, Stefan},
  issn         = {0022-1503},
  language     = {eng},
  number       = {5},
  pages        = {409--414},
  publisher    = {Oxford University Press},
  series       = {Journal of Heredity},
  title        = {The genetic basis of floral variation in Senecio jacobaea (Asteraceae)},
  url          = {http://dx.doi.org/10.1093/jhered/92.5.409},
  volume       = {92},
  year         = {2001},
}