TY - JOUR
T1 - Ecological and evolutionary opportunities of apomixis: insights from Taraxacum and Chondrilla
AU - Van Dijk, P.J.
N1 - Reporting year: 2003
Metis note: 3117; CTE; PVP; file:///L:/Endnotedatabases/NIOOPUB/pdfs/Pdfs2003/VanDijk_3117.pdf
PY - 2003
Y1 - 2003
N2 - The ecological and evolutionary opportunities of apomixis in the short and the long term are considered, based on two closely related apomictic genera: Taraxacum (dandelion) and Chondrilla (skeleton weed). In both genera apomicts have a wider geographical distribution than sexuals, illustrating the short-term ecological success of apomixis. Allozymes and DNA markers indicate that apomictic populations are highly polyclonal. In Taraxacum, clonal diversity can be generated by rare hybridization between sexuals and apomicts, the latter acting as pollen donors. Less extensive clonal diversity is generated by mutations within clonal lineages. Clonal diversity may be maintained by frequency-dependent selection, caused by biological interactions (e.g. competitors and pathogens). Some clones are geographically widespread and probably represent phenotypically plastic 'general-purpose genotypes'. The long-term evolutionary success of apomictic clones may be limited by lack of adaptive potential and the accumulation of deleterious mutations. Although apomictic clones may be considered as 'evolutionary dead ends', the genes controlling apomixis can escape from degeneration and extinction via pollen in crosses between sexuals and apomicts. In this way, apomixis genes are transferred to a new genetic background, potentially adaptive and cleansed from linked deleterious mutations. Consequentl [KEYWORDS: asexual, geographical parthenogenesis, clonal diversity, mutation accumulation, ancient asexuals]
AB - The ecological and evolutionary opportunities of apomixis in the short and the long term are considered, based on two closely related apomictic genera: Taraxacum (dandelion) and Chondrilla (skeleton weed). In both genera apomicts have a wider geographical distribution than sexuals, illustrating the short-term ecological success of apomixis. Allozymes and DNA markers indicate that apomictic populations are highly polyclonal. In Taraxacum, clonal diversity can be generated by rare hybridization between sexuals and apomicts, the latter acting as pollen donors. Less extensive clonal diversity is generated by mutations within clonal lineages. Clonal diversity may be maintained by frequency-dependent selection, caused by biological interactions (e.g. competitors and pathogens). Some clones are geographically widespread and probably represent phenotypically plastic 'general-purpose genotypes'. The long-term evolutionary success of apomictic clones may be limited by lack of adaptive potential and the accumulation of deleterious mutations. Although apomictic clones may be considered as 'evolutionary dead ends', the genes controlling apomixis can escape from degeneration and extinction via pollen in crosses between sexuals and apomicts. In this way, apomixis genes are transferred to a new genetic background, potentially adaptive and cleansed from linked deleterious mutations. Consequentl [KEYWORDS: asexual, geographical parthenogenesis, clonal diversity, mutation accumulation, ancient asexuals]
KW - NIOO/CTE/PVP
U2 - 10.1098/rstb.2003.1302
DO - 10.1098/rstb.2003.1302
M3 - Article
SN - 0962-8436
VL - 358
SP - 1113
EP - 1121
JO - Philosophical Transactions of the Royal Society B: Biological Sciences
JF - Philosophical Transactions of the Royal Society B: Biological Sciences
IS - 1434
ER -