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  • 1990-1994  (4)
  • Oryza sativa  (2)
  • Evolution  (1)
  • Hordeum vulgare  (1)
  • Randomization test  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 84 (1992), S. 682-687 
    ISSN: 1432-2242
    Keywords: rDNA polymorphism ; Hordeum vulgaressp. vulgare ; Geographical differentiation ; Evolution ; Phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A total of 289 accessions of cultivated barley were assayed for ribosomal DNA (rDNA) polymorphisms. These accessions comprised four independent samples: (1) 79 entries from China, (2) 59 accessions from Ethiopia, (3) 59 entries from Tibet and (4) 92 entries representing 36 barley growing countries of the world (referred to as “world sample”). In all, 17 rDNA phenotypes (genotypes) were observed, which were composed 10 alleles at two rDNA loci, Rrn1 and Rrn2. The world sample contained the largest number of phenotypes and alleles and also demonstrated the highest level of diversity. Ribosomal DNA phenotypes 104, 112 and 107, 112 occurred at high frequencies worldwide. Allele 112 was the predominant allele of Rrn1 in all four samples, and 104 and 107 were the two major alleles of Rrn2 worldwide. The distributions of rDNA genotypes and alleles demonstrated a clear differentiation of two distinct barley groups: an Oriental group represented by the samples from China and Tibet, which is characterized by allele 107 at the Rrn2 locus (rDNA phenotype 107, 112); and an Occidental group, represented by Ethiopian and world samples, which is comprised mostly of allele 104 at the Rrn2 locus (rDNA phenotype 104, 112). The results also raised new questions concerning the phylogeny and evolution of cultivated barley.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 83 (1992), S. 495-499 
    ISSN: 1432-2242
    Keywords: Oryza sativa ; Phenotypic diversity ; Differentiation ; Randomization test ; RFLP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Genetic diversity and differentiation in indica and japonica groups of the cultivated rice (Oryza sativa L.) were studied by assaying DNA restriction fragment length polymorphisms of 12 indica and 14 japonica rice lines digested with three restriction endonucleases. A total of 49 probes were selected to represent the entire RFLP map at intervals of 20–30 cM. It was shown that 95 of the 145 possible probe/enzyme combinations, involving 43 probes and all three enzymes, detected restriction fragment length variation, and the degree of polymorphism varied greatly from one probe/enzyme combination to another. These results demonstrate that indica rice is genetically more diverse than japonica type. Significant differentiation between the two rice groups was detected by 33 probes representing 11 of the 12 rice chromosomes. It was deduced that the processes leading to differentiation involved a combination of molecular events that include base substitutions and insertion/deletions.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 245 (1994), S. 187-194 
    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
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 48 (1990), S. 245-251 
    ISSN: 1573-5060
    Keywords: Hordeum vulgare ; barley ; α-amylase activity ; analysis of variance ; covariance analysis ; China
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary α-Amylase activity was assayed by measuring reducing power equivalent for 80 accessions of cultivated barley, Hordeum vulgare L., representing major barley growing areas of China. Replications were applied at two different levels of the experiment and enzyme activity was assayed on four consecutive days starting on the 6th day after germination. The area under the curve formed by connecting the four data points was integrated as the measurement of α-amylase activity. The results established that there was extensive variation in α-amylase activity in cultivated barley; about three-fold difference existed among accessions assayed. Comparisons were also made between six- and two-rowed, and between covered and naked barleys. The results showed that high α-amylase activity was not necessarily associated with six-rowed type, and that covered barleys were slightly higher in α-amylase activity than naked ones.
    Type of Medium: Electronic Resource
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