Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Comparative analysis of microsatellite DNA polymorphism in landraces and cultivars of rice (1994)
    Springer
    Molecular genetics and genomics 245 (1994), S. 187-194 
    Details
    ISSN: 1617-4623
    Keywords: Genetic diversity ; Germplasm ; indica-japonica differentiation ; Oryza sativa ; Simple sequence repeat (SSR)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Genetic polymorphisms of ten microsatellite DNA loci were examined among 238 accessions of landraces and cultivars that represent a significant portion of the distribution range for both indica and japonica groups of cultivated rice. In all, 93 alleles were identified with these ten markers. The number of alleles varied from a low of 3 or 4 at each of four loci, to an intermediate value of 9–14 at five loci, and to an extra-ordinarily high 25 at one locus. The numbers of alleles per locus are much larger than those detected using other types of markers. The number of alleles detected at a locus is significantly correlated with the number of simple sequence repeats in the targeted microsatellite DNA. Indica rice has about 14% more alleles than japonica rice, and such allele number differences are more pronounced in landraces than in cultivars. The indica-japonica differentiation component accounted for about 10% of the diversity in the total sample, and twice as much differentiation was detected in cultivars as in landraces. About two-thirds as many alleles were observed in cultivars as in landraces; another two-thirds of the alleles in the cultivar group were found in modern elite cultivars or parents of hybrid rice. The majority of the simple sequence repeat (SSR) alleles that were present in high or intermediate frequencies in landraces ultimately survived into modern elite cultivars and hybrids. The greater resolving power and the efficient production of massive amounts of SSR data may be particularly useful for germplasm assessment and evolutionary studies of crop plants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00283266
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The extent of parental genotypic divergence determines maximal heterosis by increasing fertility in inter-subspecific hybrids of rice (Oryza sativa L.) (1998)
    Springer
    Molecular breeding 4 (1998), S. 205-214 
    Details
    ISSN: 1572-9788
    Keywords: Oryza sativa L. ; extent of genotypic divergence ; heterosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The magnitude of heterosis in F1 hybrids is related not only to the performance of parents per se but also to the genetic diversity between two parents. The extent of genotypic divergence between hybrid rice parents was investigated at the molecular level, using two subsets of rice materials: a subset of doubled haploid (DH) lines derived from an Indica × Japonica cross (Gui630/02428) and another subset of Indica or Japonica lines representative of a broad spectrum of the Asian cultivated rice gene pool, including landraces, primitive cultivars, historically important cultivars, modern elite cultivars, super rice and parents of superior hybrids. 57 entries deliberately selected from the 81-DH lines (in total) were testcrossed to two widely used rice lines in China, photoperiod-sensitive genic male sterile (PGMS) N422s and thermo-sensitive genic male sterile (TGMS) Peiai64s. Results of the two sets of test-cross F1 populations showed congruently that parental genotypic divergence has a relatively low impact on heterosis for the two yield components, i.e., panicle number and 1000-grain weight, but it has a great bearing on fertility parameters, i.e., filled grains per plant and seedset. Heterosis for grain yield in the two test-cross populations exhibited a sharp maximum when the proportion of Japonica alleles in the male parent was between 50 and 60%, so was the heterosis for fertility parameters correspondingly. Thus fertility parameters were the most sensitive and important factors which were influenced by the extent of parental genotypic divergence. Moreover, our results showed that parents with moderate extent of genotypic divergence played an important role in the use of inter-subspecific rice heterosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009658310154
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Relationships of differential gene expression in leaves with heterosis and heterozygosity in a rice diallel cross (1998)
    Springer
    Molecular breeding 4 (1998), S. 129-136 
    Details
    ISSN: 1572-9788
    Keywords: differential display ; gene expression ; hybrid vigor ; molecular marker heterozygosity ; Oryza sativa L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Using differential display analysis, we assessed the patterns of differential gene expression in hybrids relative to their parents in a diallel cross involving 8 elite rice lines. The analysis revealed several patterns of differential expression including: (1) bands present in one parent and F1 but absent in the other parent, (2) bands observed in both parents but not in the F1, (3) bands occurring in only one parent but not in the F1 or the other parent, and, (4) bands detected only in the F1 but in neither of the parents. Relationships between differential gene expression and heterosis and marker heterozygosity were evaluated using data for RFLPs, SSRs and a number of agronomic characters. The analysis showed that there was very little correlation between patterns of differential expression and the F1 means for all six agronomic traits. Differentially expressed fragments that occurred only in one parent but not in the other parent or in F1 in each of the respective crosses were positively correlated with heterosis and heterozygosity. And conversely, fragments that were detected in F1s but in neither of the respective parents were negatively correlated with heterosis and heterozygosity. The remaining patterns of differential expression were not correlated with heterosis or heterozygosity. The relationships between the patterns of differential expression and heterosis observed in this study were not consistent with expectations based on dominance or overdominance hypotheses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009685820649
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...