Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-2242
    Keywords: Zea mays ; Haploid induction ; Gynogenesis ; Genetics ; Inducer line
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effect of genotype on maternal haploid plant production in maize was studied. The frequency of gynogenetic plants when “Stock 6” was used as pollinator varied according to the female parent genotype. No simple relation was observed between genotypic aptitudes for gynogenetic and androgenetic development, which occured after pollination of “W23” plant carrying the “indeterminate gametophyte” gene. Furthermore, the population NS, a favorably responsive genotype to anther culture, does not exhibit exceptional ability for in vivo gynogenesis. The effect of inbreeding and the influence of maternal haploid origin suggest that specific genes control maternal haploid initiation and development. However, gynogenetic development is not limited to a particular genotype. The frequency of maternal haploids may be increased by using specific pollen parents. Attempts were made to select for a high haploidyinducing trait and the present study reports the successful development of lines that can be utilized as pollen parents to induce haploids for experimental purposes and breeding programmes. When an inbred line “WS14”, derived from the cross W23 x Stock 6, was used as pollen parent, 2%–5% maternal haploids were obtained according to the female parent genotype. A high haploidy-inducing potential is a heritable trait and may be controlled by a limited number of genes. Genetic determination of the haploidy-inducing character was examined in relation to the efficiency of the selecting method and the mechanisms involved in the origin of maternal haploids.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-2242
    Keywords: Coffee ; RAPD ; RFLP ; Linkage map ; Doubled haploids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A linkage map for coffee (Coffea canephora P.) totalling 1402 cM has been developed on the basis of a population of doubled haploids. Both RFLP markers and PCR-based markers (RAPD) were used to construct 15 linkage groups. Coffee genomic and cDNA clones provided the source of the probes. In total, 47 RFLP and 100 RAPD loci have been placed on the linkage map. A rather low DNA polymorphism rate (18% for RFLP markers and 29% for RAPD primers) was detected. Only 81% of RAPD markers and 85% of RFLP markers fit an expected 1∶1 ratio (P〈0.01). The availability of a molecular linkage map has many implications for the future development of the genetics and breeding of this commercially important crop species.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-2242
    Keywords: Key wordsCoffee  ;  RAPD  ;  RFLP  ; Linkage map  ;  Doubled haploids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A linkage map for coffee (Coffea canephora P.) totalling 1402 cM has been developed on the basis of a population of doubled haploids. Both RFLP markers and PCR-based markers (RAPD) were used to construct 15 linkage groups. Coffee genomic and cDNA clones provided the source of the probes. In total, 47 RFLP and 100 RAPD loci have been placed on the linkage map. A rather low DNA polymorphism rate (18% for RFLP markers and 29% for RAPD primers) was detected. Only 81% of RAPD markers and 85% of RFLP markers fit an expected 1:1 ratio The availability of a molecular linkage map has many implications for the future development of the genetics and breeding of this commercially important crop species.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-2242
    Keywords: Chloroplast DNA ; Coffea ; Inheritance ; RFLP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract CpDNA variation among 52 tree samples belonging to 25 different taxa of Coffea and two species of Psilanthus was assessed by RFLP analysis on both the total chloroplast genome and the atpB-rbcL intergenic region. Twelve variable characters were distinguished allowing the identification of 12 different plastomes. The low sequence divergence observed might suggest that Coffea is a young genus. The results were in contradiction with the present classification into two genera. Additionally, cpDNA inheritance was studied in interspecific hybrids between C. arabica and C. canephora, and in an intraspecific progeny of C. canephora, using PCR-based markers. Both studies showed exclusively maternal inheritance of cpDNA.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-2242
    Keywords: Key words Coffea ; Coffee-tree ; Internal transcribed spacer region ; Nuclear ribosomal DNA ; Molecular phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Phylogenetic relationships of Coffea species were estimated from the sequences of the internal transcribed spacer (ITS 2) region of nuclear ribosomal DNA. The ITS 2 region of 37 accessions belonging to 26 Coffea taxa and to three Psilanthus species was directly sequenced from polymerase chain reaction (PCR)-amplified DNA fragments. The level of variation was high enough to make the ITS 2 a useful tool for phylogenetic reconstruction. However, an unusual level of intraspecific variation was observed leading to some difficulty in interpreting rDNA sequence divergences. Sequences were analysed using Wagner parsimony as well as the neighbour-joining distance method. Coffea taxa were divided into several major groups which present a strong geographical correspondence (i.e. Madagascar, East Africa, Central Africa and West Africa). This organisation is well supported by cytogenetic evidence. On the other hand, the results were in contradiction with the present classification of coffee-tree taxa into two genera, namely Coffea and Psilanthus. Furthermore, additivity of parental rDNA types was not observed in the allotetraploid species C. arabica.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-2242
    Keywords: Key wordsCoffea canephora  ;  Self-incompatibility  ;  Gametophytic system  ;  S-locus  ;  RFLP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cross-compatibility behaviour of doubled haploid (DH) and hybrid genotypes of Coffea canephora was established using both phenotypic bioassay and in situ seed-set examination. The availability of DHs provided the opportunity of working with genetically homogenous pollen and female parents. The aniline blue fluorescence (ABF) method was applied to detect callose accumulation in pollen and pistil. Clear cross-compatibility/incompatibility situations were observed and confirmed by in situ seed-set analysis. Cross-compatibility analysis of hybrid combinations involving different DHs corroborated the crossing behaviour observed at the DH level. Expression of the self-incompatibility system did not appear to be affected by the low vigour of the DH. The crossing-behaviour distribution observed within DHs derived from clone IF200 confirmed that self-incompatibility in C. canephora is a gametophytic self-incompatibility system controlled by a single locus (S-locus). Reduced seed-set developments following incompatible crosses may indicate the occurrence of pseudo-incompatibility. Molecular marker linkage analysis showed that the S-locus is associated with an RFLP marker on linkage group 9. The availability of a linked DNA marker should facilitate the genetic analysis of self-incompatibility in relation to coffee breeding programmes.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-2242
    Keywords: Zea mays ; Haploid ; Gynogenesis ; Gametophytic selection ; Genetic markers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Experiments were conducted to investigate whether selection occurs during the processes involved in the production of doubled haploids. Haploid plants produced from two hybrids, each heterozygous for isozyme markers, were subjected to genetic analysis. The distributions of doubled haploid lines and pedigree lines derived from the hybrid C123 x Oh7 were compared with regard to agronomic character. The results suggest that the populations of haploid plants obtained by in vivo gynogenesis represent a random gametic array. Thus, in order to introduce haploid plants into breeding programmes in maize, maternal haploidy seems to be a very attractive method.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-2242
    Keywords: Key words Chloroplast DNA ; Coffea ; Inheritance ; RFLP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract CpDNA variation among 52 tree samples belonging to 25 different taxa of Coffea and two species of Psilanthus was assessed by RFLP analysis on both the total chloroplast genome and the atpB-rbcL intergenic region. Twelve variable characters were distinguished allowing the identification of 12 different plastomes. The low sequence divergence observed might suggest that Coffea is a young genus. The results were in contradiction with the present classification into two genera. Additionally, cpDNA inheritance was studied in interspecific hybrids between C. arabica and C. canephora, and in an intraspecific progeny of C. canephora, using PCR-based markers. Both studies showed exclusively maternal inheritance of cpDNA.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-2242
    Keywords: Coffea canephora ; Self-incompatibility ; Gametophytic system ; S-locus ; RFLP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cross-compatibility behaviour of doubled haploid (DH) and hybrid genotypes of Coffea camphora was established using both phenotypic bioassay and in situ seed-set examination. The availability of DHs provided the opportunity of working with genetically homogenous pollen and female parents. The aniline blue fluorescence (ABF) method was applied to detect callose accumulation in pollen and pistil. Clear cross-compatibility/incompatibility situations were observed and confirmed by in situ seed-set analysis. Cross-compatibility analysis of hybrid combinations involving different DHs corroborated the crossing behaviour observed at the DH level. Expression of the self-incompatibility system did not appear to be affected by the low vigour of the DH. The crossing-behaviour distribution observed within DHs derived from clone IF200 confirmed that self-incompatibility in C. canephora is a gametophytic self-incompatibility system controlled by a single locus (S-locus). Reduced seed-set developments following incompatible crosses may indicate the occurrence of pseudo-incompatibility. Molecular marker linkage analysis showed that the S-locus is associated with an RFLP marker on linkage group 9. The availability of a linked DNA marker should facilitate the genetic analysis of self-incompatibility in relation to coffee breeding programmes.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1617-4623
    Keywords: Key words Africa ; Amphidiploidy ; Coffee tree ; Molecular cytogenetics ; Restriction fragment length polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Restriction fragment length polymorphism (RFLP) markers were used in combination with genomic in situ hybridisation (GISH) to investigate the origin of the allotetraploid species Coffea arabica (2n = 44). By comparing the RFLP patterns of potential diploid progenitor species with those of C. arabica, the sources of the two sets of chromosomes, or genomes, combined in C. arabica were identified. The genome organisation of C. arabica was confirmed by GISH using simultaneously labelled total genomic DNA from the two putative genome donor species as probes. These results clearly suggest that C. arabica is an amphidiploid formed by hybridisation between C. eugenioides and C. canephora, or ecotypes related to these diploid species. Our results also indicate low divergence between the two constituent genomes of C. arabica and those of its progenitor species, suggesting that the speciation of C. arabica took place relatively recently. Precise localisation in Central Africa of the site of the speciation of C. arabica, based on the present distribution of the coffee species, appears difficult, since the constitution and extent of tropical forest has varied considerably during the late Quaternary period.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...