The Role of Small Populations for the Differentiation in Plants

Runemark, Hans

doi:10.2307/1217954

Cited by 23 publications

(20 citation statements)

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“…Later, the species was found to be more common on the Kiklades and was also reported from a few islets of the Dodekanese (Runemark 1969). In the late 1980's, additional data extended the known distribution range of the species, as it was found on the islet Avgo north of Crete [35°36'10''N, 25°34'40''E] (Greuter & Pieper 1975), the islet Stomata west of Karpathos [35°48'00''N, 27°12'50''E] (Pleger unpubl.…”

Section: Distributionmentioning

confidence: 89%

“…The flora of these islets does not represent a random selection from the coastal flora of the neighbouring larger islands, but consists mainly of about 25 well-adapted specialists. This peculiar species composition has attracted the interest of many botanists (Runemark 1969, 1970, 1971a-b, Bothmer 1974, Gustafsson & Snogerup 1974, Greuter & Pieper 1975, Snogerup & Snogerup 1987, 2004, Höner & Greuter 1988, Raus 1990, Christodoulakis & al. 1991, Höner 1991, Panitsa & al.…”

Section: Introductionmentioning

confidence: 99%

“…Like all islet specialists, A. scopulorum shows an uneven and scattered distribution in the area, usually being abundant on the islets where it grows, but completely absent from neighbouring islets despite the occurrence of the same suitable habitats. This is supposedly due to a reduced possibility to establish stable populations and a great extinction risk (Runemark 1969).…”

Section: Introductionmentioning

confidence: 99%

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Anthemis scopulorum (Asteraceae), an “islet specialist” endemic to the Aegean islands (Greece)

2006

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Section: Distributionmentioning

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Anthemis scopulorum (Asteraceae), an “islet specialist” endemic to the Aegean islands (Greece)

2006

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“…A SEWALL WRIGHT effect is very likely to be of great evolutionary significance for various plant species in the Aegean area (RUNEMARK 1970). The possibility of random fixation of structural and genetical peculiarities has also been pointed out in other Aegean species (SNOGERUP 1967;STRID 1970;BENT-ZER 1973;BOTHMER 1974) as well as in other materials growing in small populations (e.g.…”

Section: B Drgt and Founder Effectmentioning

confidence: 97%

Chromosomal polymorphism in isolated populations of Elymus (Agropyron) in the Aegean:

Heneen

2009

Hereditas

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A striking chromosomal polymorphism predominates in Elymus striatulus (2n = 14), E. rechingeri (2n = 28) and E. diue (2n = 56) which grow in small isolated populations largely on the Aegean islands. The polymorphism was expressed mainly in the existence of several variant types of the satellite chromosomes. Satellite chromosomes might be more susceptible to structural alterations due to the presence of secondary constrictions, nucleolar organizers, heterochromatic blocks and repetitive DNA which are known to be labile sites. Chromosomal polymorphism was more pronounced in the two polyploid species which might be attributed to the compensatory effect of the high number of homologous, homoeologous or related genomes in the polyploids. Chromosomal polymorphism was also favored by the rhizomatous or tufted patterns of vegetative growth of these species. The evolutionary aspects of the chromosomal, genetical and morphological differences between populations might be related to ( I ) inbreeding of crossfertilizers and selection for chromosomal heterogeneity and/or (2) drift or a founder effect which is also supported by the paleogeographical records. The species in the Aegean area are apparently in an active phase of evolutionary change. W . K . Heneen, Institute of Genetics, University of Lund, S-223 62 Lund. SwedenElymus striatulus (2n = 14), E. rechingeri (2n = 28) and E. dine (2n=56) are three littoral species found by RUNEMARK in the Aegean. They grow in small isolated populations. Seeds collected from natural populations mainly on the Aegean islands were grown under greenhouse conditions. Cytological analysis of the plants raised from these seeds provided evidence for the prevalence of chromosomal polymorphism in the three species (HENEEN and RUNEMARK 1962, 1972 HENEEN 1977a, b, c). This polymorphism was manifested in the variable appearance of the satellite chromosomes and the presence of structurally new chromosome types (markers).In Table 1 a summary is presented of the data on the numbers of plants studied and the populations they represented, and also the number of satellite and marker chromosome constitutions present. The appearance of the different types of the satellite and marker chromosomes is shown schematically in Fig. 1. Satellite chromosome types A and B were found in all three species which indicates a similarity or close similarity between these species with respect to at least one genome. Variants of satellite types A and B as well as variants of type C (found only in E. rechingeri) were present either in a homo-or heterozygous condition.Satellite chromosome constitutions that were most common and thus most probably characteristic for the species were A2A2 BIBl for E. striatulus, A2A2 BIB1 C2C2 for E. rechingeri and possibly AA AA BB for E. diue. The original papers (cited above) should be consulted for details on numerical, structural and pairing peculiarities of the chromosomes in the three species and in the offspring from inter-and intrapopulation crosses in the case of E. rechingeri.The pre...

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“…This chromosomal reduction is probably the result of successive chromosomal reconstructions and fusion of acrocentric chromosomes into metacentric chromosomes (Darlington 1930, 1936, La Cour 1978a-b, Kamari 1991. The presence, shape and size of satellites on chromosomes vary significantly among members of the genus, and even within the same taxon (Runemark 1970, Bentzer & al. 1971, Mehra & Sachdeva 1976, Koul & Wafai 1980, Kamari 1984, 1991, 1996, Zaharof 1987.…”

Section: Karyologymentioning

confidence: 99%