摘要:

TwoElymusspecies,E. cacuminus(2n = 4x = 28) andE. retroflexus(2n = 2x = 28). native to western China are described as species new to science. In order to determine genomic constitutions of the two species, intergeneric and interspecific hybridizations were carried out between the two new species andPseudoroegneria spicata(2n = 2x = 14, SS), and sixteen otherElymusspecies, fifteen tetraploids (2n = 4x = 28) and one hexaploid (2n = 6x = 42), containing the “SH”, “SY”, and “SYH” genomes. Chromosome pairing behaviour was studied in the two species and their hybrids. Generally low meiotic pairing was observed in the hybrids with S‐ and SH‐genome species and high pairing in the hybrids with SY‐ and SYH‐genome species. It is concluded from this study that (i) the two new species are strict allotetraploid (2n = 4x = 28) and self‐pollinating taxa (inbreeders) in nature; (ii) they contain the “SY” genomes and; (iii) they have close genomic relationships with the SY‐genomeElymusspecies from the same or ge

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00062.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.tb00063.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

The closely relatedSenecio nebrodensis, a perennial herb from four mountain ranges in Spain, andS. viscosus, an annual herb widespread in Europe, are being compared by the study of herbarium material and comparative cultivation. In cultivation, S.nebrodensisbehaved as an annual, completing its life cycle within a shorter period of time thanS. viscosus. The formation of basal leaf rosettes is much more pronounced in S.nebrodensisthan in S.viscosus. The main difference between the two species, however, is their breeding system. While S.nebrodensisis self‐incompatible,S. viscosusis self‐compatible. Differences in reproductive morphology (mainly size and number of ray florets) are suggested to be related to this difference in breeding system. Despite differences in disc floret number and capitulum number observed in the cultivated material, the potential reproductive output of the two species is roughly comparable.Senecio viscosusis believed to be a descendant of S.nebrodensis. It is postulated that the former differentiated from thelatter at the latest in glacial or early postglacial times. Following postglacial climatic changes, S.nebrodensisretreated into high altitudes, whileS. viscosus, adapting to these changes, expanded northwards. The strikingly different degree to which the two species exploit man‐made disturbances is interpreted as being due to a difference in opportunity: In its climatically defined rangeS. nebrodensisexperiences little disturbance.Senecio viscosus, on the other hand, inhabits areas strongly disturbed by human activity. It is concluded thatS. viscosusshows no obvious adaptations to its habitat, but is well pread

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00064.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.tb00065.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Lychnis alpinais a perennial caryophyllaceous plant with an amphi‐Atlantic distribution. 27 populations are described on the basis of allozyme data from 11 electro‐phoretic loci.L. alpinahas a relatively low level of genetic variation, 3 of the loci are polymorphic (P.,%=20.2%) and the mean expected heterozygosity per indivindual is H3= 0.233 the three polymorphic loci included (H = 0.064, 11 loci included). Despite relatively low level of genetic variation, the genetic diversity among populations is relatively high with FST= 0.51. A hierarchial analysis of genetic diversity demonstrates that most of the genetic diversity exists as interpopulational, intra‐regional diversity. Genetic identity is not associated with the intercontinental geographical distribution of the populations, neither is the diversity correspondant to taxonomic relation

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00066.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.tb00067.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Hordeum depressumis a distinct, reproductively isolated, tetraploid species. The study of meiosis in hybrids with the closest congeneric relatives revealed intermediate to low pairing with most species. The exceptions areHordeum brachyantherumssp.californicumandH. arizonicum. H. depressum, probably share one highly similar genome with ssp.californicumand perhaps two withH. arizonicum. However, it is difficult to draw firm conclusions based only on meiotic figures, since the pairing may be disturbed by high autosyndetic pairing between theH. depressurngenomes.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00068.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Pelargonium wonchienseis described as new from Ethiopia. It is an annual species with minute flowers, and falls in the sectionPeristeraof which the centre of diversity lies in the south‐western Cape Province of South Afric

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00069.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

One new species,Bauhinia cercidifoliaand one new variety,B. khasianavar.gigalo‐biaare described from China.B. yunnanensisis recognized as a new series by its distinction from all the groups known.B. nervosaandB. strychnoideaare recorded from China for the first tim

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00070.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

As a precursor for the treatment of Caesalpiniaceae in Flora Malesiana the following new combinations are proposed:Cassia javanicassp.pubiflorastat. nov.,C. javanicassp.agnesstat. nov.,C. javanicassp.microcalyxstat. nov.C. javanicassp.renigerastat. nov.,C. javanicassp.bartoniistat. nov.,Senna divaricatacomb. nov.,Chamae‐christa pumilacomb. nov. andChamaechrista mindanaensiscomb. no

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1993.tb00071.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY