摘要:

101 populations of NordicDrabawere investigated for chromosome numbers and crossing relationships. The populations were referred to 16 currently recognized species of Sect.Draba, Sect.Chrysodraba(including theD. alpinacomplex withD. alpina, D. oxycarpa, andD. corymbosa), and Sect.Drabella. The chromosome data suggest that all populations and species are homoploid. Three species are diploid, and 13 species are polyploids ranging from tetraploid to 16‐ploid.Draba alpinais decaploid,D. oxycarpais octoploid, andD. corymbosais 16‐ploid. The chromosome numbers ofD. micropetala(n = 16,4x) andD. adamsii(n = 24,2n = 48, 6x) of Sect.ChrysodrabaandD. cinerea(n = 24, 6x) of Sect.Drabawere determined for the first time based on Nordic material. The relationships inferred from the crossing data largely agree with those inferred from previously published molecular data, but correspond poorly to relationships inferred from morphology. Inter‐populational F1hybrids inD. fladnizensiswere entirely sterile, suggesting that this predominantly inbreeding diploid species comprises at least two sibling species, possibly isolated by genic barriers. Sterile to semifertile F1hybrids with intermediate chromosome numbers were obtained in 19 interspecific combinations. F2hybrids were obtained in seven of these combinations. Both Sect.Chrysodrabaand theD. alpinacomplex are probably polyphyletic. The crossing data suggest that the morphologically very similar polyploidsD. alpina(10x) andD. oxycarpa(8x) do not have any diploid progenitors in common, and that Sect.Drabaforms an intricate allopolyploid complex that also includesD. alpinaandD. corymbosaof Sect.Chrysodraba. Draba corymbosa(16x) is probably an intersectional, polyphyletic alloploid derived fromD. alpina(10x) and various hexaploids of Sect.Draba. Crossing data also suggest thatD. norvegica(6x) is one of the progenitors of the Nordic endemicD. cacuminum(8x). The phenotypic expression of genes encoding taxonomically important indument characters did not follow consistent patterns in interspecific hybrids. This result may explain the discrepancy between genetic and taxonomic relationships in NordicDraba, and supports the use of wide taxonomic concepts in this highly reticulate

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00023.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00024.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Reproductive ecology (pollination biology, breeding systems, and reproductive effort and success) of the three Nordic species ofPinguicula, P. alpina, P. villosa, andP. vulgaris(Lentibulariaceae), was investigated in a subarctic‐subalpine area at Abisko, N Swedish Lapland. Additional studies were carried out at Latnjajaure Field Station, a subarctic‐alpine tundra site in the Abisko mountains (P. alpina, P. vulgaris), and in W Greenland (P. vulgaris). At Abisko the species are sympatric and large populations of all three were found within a 50 × 50 m area. The three species are reproduc‐tively isolated by internal barriers by occupying different ploidy levels.Pinguicula alpinaandP. vulgaristhrive in base‐rich habitats, whereasP. villosais restricted to nutrient‐poorSphagnumbogs, but habitat separation alone is probably not sufficient to prevent illegitimate pollen flow among the species. However, results showed that there are large and consistent differences in pollination biology, flowering phenology, and breeding systems, and these factors interact to create a highly efficient reproductive isolation at all levels, pre‐zygotic as well as post‐zygotic.Pinguicula alpinais an early‐flowering outbreeder,P. vulgarisis an opportunistic late‐flowering inbreeder, andP. villosais quite intermediate between the two extremes. The phenology‐based life history strategies of thePinguiculaspecies were in accordance with a general model developed for arctic flowering plants, predicting maximized fitness through pollen or seed in early‐ and late‐floweri

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00025.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00026.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

A new species,Scilla merinoi, from Galicia is described and illustrated. The similarities between the new taxon and two related species,S. odorataandS. verna, are discussed. Together with a morphological comparison of the three species, scanning electron micrographs of seeds and a map of the new species' known distribution are presented.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00027.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00028.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Tetragonia pentandra, previously believed to be an endemic of Socotra, is reported from northern Somalia.T. retusasp. nov., a very distinctive endemic of central Somalia with features that partly linkTetragoniaandTribulocarpus, is described and illustrated.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00029.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00030.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Mollugo angustifoliasp. nov., from sandy plains of the Bay Region in southern Somalia, is described and illustrated.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00031.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Phyllanthus lunifoliussp. nov., a completely prostrate dwarf shrub from limestone rocks in the coastal part of central Somalia, is described and illustrated.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00032.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY