Showing papers in "Genome in 1988"
TL;DR: Four hundred random DNA fragment clones of wild diploid wheat Triticum monococcum ssp.
Abstract: Four hundred random DNA fragment clones of wild diploid wheat Triticum monococcum ssp. aegilopoides (syn. T. baeoticum) were screened for clones of repeated nucleotide sequences. Seven DNA fragment...
292 citations
TL;DR: A complete set of disomic substitution lines have been developed in the tetraploid wheat cultivar Langdon (Triticum turgidum L. var. durum) and their phenotypic characteristics, their cytogenetic behavior, and suggested methods for their use are described.
Abstract: A complete set of disomic substitution lines have been developed in the tetraploid wheat cultivar Langdon (Triticum turgidum L. var. durum). These aneuploid lines each have a pair of durum wheat homoeologues replaced by a pair of D-genome chromosomes transferred from 'Chinese Spring' hexaploid wheat. They can be used to determine the chromosomal location of genes, to transfer chromosomes from one cultivar or line of tetraploid wheat to another, to study the cytogenetics of tetraploid wheat, to determine gene linkages, and to identify chromosomes involved in translocations. Their phenotypic characteristics, their cytogenetic behavior, and suggested methods for their use are described.Key words: cytogenetics, monosomic, chromosome transmission, telosomic, chromosome substitution.
176 citations
TL;DR: The disomic addition line for 5J showed considerable tolerance to salt and at 200 mol m−3 NaCl produced a similar response to that of the amphiploid in producing fertile tillers and both produced viable tillers.
Abstract: Two wheat – Agropyron junceum disomic addition lines homoeologous to groups 2 and 5 were tested for tolerance to salt. The experiments included germination and growth to maturity at various concent...
74 citations
TL;DR: The study of Brassica napus L. plants carrying restorer genes introgressed from radish showed that these genes ensured restoration of male fertility in rapeseed for all the male sterility-inducing cytoplasm studied, i.e., "Ogura"-type cy toplasm and that of four cybrids obtained by protoplast fusion.
Abstract: The study of Brassica napus L. plants carrying restorer genes introgressed from radish (Raphanus sativus L.) showed that these genes ensured restoration of male fertility in rapeseed for all the male sterility-inducing cytoplasm studied, i.e., "Ogura"-type cytoplasm and that of four cybrids obtained by protoplast fusion. Plants with high levels of restored male fertility were obtained. However, the introduction of restorer genes was accompanied by a large decrease in seed set. Observations of embryo sacs inside the ovules and correlation between number of seeds per pod and percentage of octonucleate embryo sacs indicated that low seed set could be attributed to a high rate of embryo sac abortion, mainly at the uninucleate stage. Introduction of too much radish genetic information was assumed to be the cause of this low female fertility. Female fertility must be improved before the restored material can be used for F1 hybrid rapeseed production.Key words: Brassica napus, Raphanus sativus, cytoplasmic male ...
72 citations
TL;DR: Cytological and molecular hybridization studies suggested that the BYDV resistance in Zhong 4 is carried on a set of seven pairs of nonwheat chromosomes that derived from a combination of the E and X genomes present in Th.
Abstract: Resistance to barley yellow dwarf virus (BYDV) has been described in lines derived from crosses between wheat and Thinopyrum intermedium. The resistance in one such line, Zhong 4, originating in China, was expressed against two different serotypes of BYDV as measured by accumulation of virus in infected seedlings. F1 hybrids between wheat (2n = 42) and Zhong 4 (2n = 56) had 49 chromosomes and intermediate levels of virus when compared to the parent lines. Cytological and molecular hybridization studies suggested that the BYDV resistance in Zhong 4 is carried on a set of seven pairs of nonwheat chromosomes that derived from a combination of the E and X genomes present in Th. intermedium.Key words: Barley yellow dwarf virus, wheat, ribosomal DNA, Agropyron intermedium, Thinopyrum intermedium, virus resistance.
71 citations
TL;DR: The unique C-banding patterns of several chromosomes in each species will be a useful tool for the study of meiotic behaviour in interspecific hybrids among Avena spp.
Abstract: Giemsa C-banding was used to identify individual somatic chromosomes in eight diploid species of Avena. Two patterns of heterochromatin distribution were found. The chromosomes of five A genome spe...
68 citations
TL;DR: The fluorescent banding patterns of the chromosomes of Salmo gairdneri (rainbow trout), Salmo trutta (brown trout), and Salmo salar from North America and Great Britain are described.
Abstract: The fluorescent banding patterns of the chromosomes of Salmo gairdneri (rainbow trout), Salmo trutta (brown trout), and Salmo salar (Atlantic salmon) from North America and Great Britain are described. Quinacrine stained a subset of C bands in S. gairdneri and S. salar from North America. No bright quinacrine (Q) bands were found on the chromosomes of S. salar from Great Britain or the chromosomes from any of the three stocks of S. trutta that were examined. Q bands were found at the centromeres of three to seven different chromosome pairs in S. gairdneri, including the pair that has been identified as the sex chromosome pair in some populations. In S. salar from North America the Q bands were found at the teleomeres of three to four chromosome pairs and at interstitial locations in the 10–13 large acrocentric chromosome pairs. Chromomycin A3 stained either the nucleolar organizer region or the adjacent heterochromatin or both in all three species. In S. trutta the entire short arm of the acrocentric chro...
65 citations
TL;DR: The Giemsa C-banding pattern of the chromosomes of five tetraploid species of Avena have been studied and fewer nucleoli and nucleolar organizer regions (NORs) were observed than expected, assuming complete additivity of those from the donor diploids species.
Abstract: The Giemsa C-banding pattern of the chromosomes of five tetraploid species of Avena have been studied. The chromosomes of AABB species (A. barbata, A. vaviloviana, and A. abyssinica) had similar C-banding patterns to those of A genome species. AACC species (A. maroccana and A. murphyi) possessed two sets of seven chromosome pairs with C-banding patterns similar to those observed in the diploid A and C genome species. However, no good correspondence between either of these two chromosome groups and any one diploid species has been found. When the nucleolar organizer activity of the species was analysed by silver staining, fewer nucleoli and nucleolar organizer regions (NORs) were observed than expected, assuming complete additivity of those from the donor diploid species.Key words: C-banding, NOR, Avena, heterochromatin.
65 citations
TL;DR: Fifteen mutants with increased powdery mildew susceptibility were crossed with the Ml-a12 resistant mother line 'Sultan-5' and the susceptible variety 'Carlsberg II' and analysis of the material revealed that 13 mutants had mutational modifications of the M l-a 12 gene.
Abstract: Fifteen mutants with increased powdery mildew susceptibility (infection types between 0–1 and 3–4) were crossed with the Ml-a12 resistant mother line 'Sultan-5' (infection type 0) and the susceptible variety 'Carlsberg II'. Analysis of the material revealed that 13 mutants had mutational modifications of the Ml-a12 gene. Two mutants had a suppressor-mutant gene that modified the phenotypic expression of gene Ml-a12. One suppressor gene was recessive, the other was semidominant. The possible function of gene Ml-a12 is discussed.Key words: barley, Hordeum vulgare, powdery mildew, Erysiphe graminis hordei, mutation, resistance, suppressor.
65 citations
TL;DR: The nuclear data show a sharp transition between the two subspecies of mice, most of the variations in allele frequencies occurring within a 36-km section of the transect, and mitochondrial DNA introgression varies from one locus to the other and is more pronounced, in terms of distance, in M. m.
Abstract: The hybrid zone between the two subspecies of mice Mus musculus domesticus and Mus musculus musculus, which has been studied extensively in Denmark, crosses Europe to the Black Sea through the Alps and the Balkans. Two hundred and seventy-nine animals were captured in 22 localities along a transect across the Balkans. The animals were characterized for seven diagnostic nuclear loci by protein electrophoresis and by restriction pattern analysis of their mitochondrial DNA. The nuclear data show a sharp transition between the two subspecies, most of the variations in allele frequencies (from 0.9 to 0.1) occurring within a 36-km section of the transect. The introgression varies from one locus to the other and is more pronounced, in terms of distance, in M. m. musculus territory. Mitochondrial DNA introgression is important but occurs in one direction only, i.e. from M. m. musculus to M. m. domesticus, while a cytoplasmic transfer from M. m. domesticus to M. m. musculus has been reported. A previous study show...
64 citations
TL;DR: Genotype-temperature interactions could underlie a substantial amount of phenotypic variation in the developmental characters examined for both pink and chum salmon.
Abstract: A factorial mating design was employed in which five males were mated to each of five females in each of two stocks for both pink and chum salmon. The resulting embryos and alevins were incubated at constant water temperatures of 4, 8, and 16 °C for pink salmon and 3, 8, and 15 °C for chum salmon. Variation among families in alevin and fry survival rates, hatching, button-up time, length, and weight was the least at 8 °C. Heritability of traits directly correlated with fitness, such as survival rates and button-up time, was low at all temperatures (h2 ≤ 0.25). Maternal effects could account for a substantial portion of the variation in alevin and fry size characters. Nonadditive genetic variance accounted for more of the variation in fry size characters than in those of alevins. Negative genetic correlations were observed between embryo survival and subsequent alevin size and between hatching time and subsequent alevin and fry size. Genotype–temperature interactions could underlie a substantial amount of ...
TL;DR: The positional distribution of late recombination nodules along synaptonemal complexes corresponds almost exactly to the distribution of chiasmata along metaphase I bivalents in the two species.
Abstract: Pachytene synaptonemal complexes and recombination nodules were analysed, by surface spreading, in the closely related species Allium fistulosum and Allium cepa (both 2n = 16), which show highly co...
TL;DR: The wheat curl mite (Eriophyes tulipae Keifer) is the vector of wheat streak mosaic virus, a damaging disease of winter wheat, and a translocation between a common wheat chromosome and a group 6 chromosome from decaploid Agropyron elongatum (Host) Beauv resulted in transfer of resistance to colonization by the wheat curled mite.
Abstract: The wheat curl mite (Eriophyes tulipae Keifer) is the vector of wheat streak mosaic virus, a damaging disease of winter wheat. A translocation between a common wheat (Triticum aestivum L.) chromoso...
TL;DR: Isoelectric focusing separations of aqueous extracts of mature embryo tissue of 'Chinese Spring' wheat confirmed the previous gene location of the endopeptidase-1 (Ep-1) homoeoallelic series to the long arms of the group 7 chromosomes.
Abstract: Isoelectric focusing separations of aqueous extracts of mature embryo tissue of 'Chinese Spring' wheat (Triticum aestivum) confirmed the previous gene location of the endopeptidase-1 (Ep-1) homoeoallelic series to the long arms of the group 7 chromosomes. Screening of a range of wheat varieties revealed a significant degree of polymorphism at each of the three loci, Ep-A1, Ep-B1, and Ep-D1, including three alleles at Ep-A1, five at Ep-B1, and three at Ep-D1. One allele at each locus was null. Polymorphism at Ep-B1 allowed this locus to be mapped both with respect to a number of other markers on 7BL and from the breakpoint of the 5BL.7BL translocation. A close linkage with the leaf rust resistance gene Lr14a was established and the locus was independent of the centromere. A number of alien relatives of wheat were found to carry distinct homoeoalleles on their group 7 chromosomes.Key words: wheat, endopeptidase, isozymes, isoelectric focusing.
TL;DR: Gene expression for cold hardiness was investigated in a number of interspecific or intergeneric hybrids and amphiploids of wheat to assess the potential of alien species as donors of cold-hardiness genes for the improvement of wheat.
Abstract: Gene expression for cold hardiness was investigated in a number of interspecific or intergeneric hybrids and amphiploids of wheat (Triticum aestivum L. em. Thell. or T. turgidum L.) and other members of the tribe Triticeae to assess the potential of alien species as donors of cold-hardiness genes for the improvement of wheat. Thinopyrum ponticum (Agropyron elongatum) hybrids with nonhardy T. aestivum had cold-hardiness levels similar to that of the more hardy Thinopyrum parent. Hybrids of Triticum cylindricum and both hardy and nonhardy T. aestivum were intermediate in cold hardiness with a tendency toward greater hardiness than the parental mean. Cold hardiness of hybrids between T. aestivum and Thinopyrum intermedium (Agropyron intermedium) was also close to the parental midpoint. Cold hardiness of T. aestivum – Secale cereale hybrids was greater than the less hardy parent. In contrast, cold-hardiness genes were not expressed beyond the level of the wheat parent in amphiploids combining wheat and the ve...
TL;DR: Both overall frequency and phenotypic distribution of types of gonadal hermaphrodites identify three classes of domesticus-type Y chromosome by their differential interaction with the C57BL/6J genetic background.
Abstract: The Y chromosome of Mus musculus poschiavinus interacts with the autosomal recessive gene tda-1b of the C57BL/6J laboratory strain of the house mouse to cause complete or partial sex reversal. Ovaries or ovotestes develop in a substantial proportion of the XY fetuses. Several different Y-specific DNA probes distinguish two major types of Y chromosome in the house mouse and they are represented by M. m. domesticus and M. m. musculus. The poschiavinus Y chromosome appears identical to the domesticus Y. The developmental distribution of the gonad types was examined in the first backcross or N2 generation of fetuses in C57BL/6J with six different domesticus-type Y chromosomes and, as controls, three different musculus-type Y chromosomes. Gonadal hermaphrodites were found with three of the six domesticus-type Y chromosomes. Both overall frequency and phenotypic distribution of types of gonadal hermaphrodites identify three classes of domesticus-type Y chromosome by their differential interaction with the C57BL...
TL;DR: Comparisons of the chromosomes of the B genome of T. turgidum with the karyotypes of the six putative B genome donors showed that only the kARYotype of Aegilops searsii was similar to the one deduced for the donor of theB genome in T. Turgidums, suggesting that Ae.
Abstract: To help elucidate the origin of the B genome in polyploid wheats, karyotypes of Triticum turgidum, Triticum monoccum, and all six purported B genome donors were compared The analysis utilized a common cytological procedure that employed the most advanced equipment for the measurement of chromosome lengths at metaphase in root tip cells A comparison of the karyotypes of T turgidum and T monococcum permitted the identification of B genome chromosomes of T turgidum These consist of two SAT pairs, one ST pair, three SM pairs, and one M pair of homologues Comparisons of the chromosomes of the B genome of T turgidum with the karyotypes of the six putative B genome donors showed that only the karyotype of Aegilops searsii was similar to the one deduced for the donor of the B genome in T turgidum, suggesting that Ae searsii is, therefore, the most likely donor of the B genome to the polyploid wheats Support for this conclusion has been derived from geographic, DNA-hybridization, karyotype, morphologica
TL;DR: Cytologically identical aberrations were observed in plants regenerated at various time points in the pedigreed cultures, indicating an early occurrence of the aberration during culture maintenance.
Abstract: Cytogenetic instability in maize plants regenerated from tissue culture is a commonly observed phenomenon. In an attempt to understand the origin of this instability meiotic analyses were performed on 370 regenerated plants that were initiated from cell lines of 22 immature embryos of 9 maize genotypes. Cell lineage pedigrees were maintained on these cultures to record the familial relationship between regenerated plants. Overall, 12.4% of the 370 regenerants contained cytological aberrations. The largest category of aberrations involved chromosome breakage (translocations, deletions, and an inversion) between a heterochromatic knob or knob site and the centromere. Late replicating knob heterochromatin might have been responsible for the chromosome breakage events. Cytologically identical aberrations were observed in plants regenerated at various time points in the pedigreed cultures, indicating an early occurrence of the aberration during culture maintenance. Heterogeneity of cell karyotypes also was obs...
TL;DR: Crossability rate, hybrid inviability, and meiotic pairing in intra- and inter-specific F1 hybrids revealed that genomically similar species, though morphologically distinct, crossed readily to produce hybrid progeny that were vigorous, fertile, and normal in meiotic Pairing.
Abstract: The present study furnishes information about the current status of knowledge concerning the genomic relationships among 9 of the 12 wild perennial species (2n = 40) of the subgenus Glycine. Crossability rate, hybrid inviability, and meiotic pairing in intra- and inter-specific F1 hybrids revealed that genomically similar species, though morphologically distinct, crossed readily to produce hybrid progeny that were vigorous, fertile, and normal in meiotic pairing (20 bivalents at metaphase I). However, a chromatin bridge and acentric fragment were recorded in certain hybrid combinations, suggesting that the evolutionary divergence in genomically similar species occurred because of paracentric inversions. In contrast, crosses between genomically dissimilar species set pods that often aborted, showed hybrid weakness, seedling and vegetative lethality, seed inviability, and complete sterility. The sterility was attributed to disturbed meiotic pairing. It is obvious from this study that A-genome species such a...
TL;DR: A complex organized length heterogeneous 5' external spacer built up of different numbers of 340 bp subrepeats, each flanked by 52 bp direct repeats, is detected and described for the first time for plant ribosomal DNA repeating units.
Abstract: Restriction enzyme analysis and cloning of the 18S, 5.8S, and 25S ribosomal RNA genes (rDNA) of the mung bean (Vigna radiata = Phaseolus aureus) reveal length heterogeneity in the repeating units (10-11 kbp) localized within two different regions in the ribosomal spacer. The 1.5-2.0 kbp region flanking the 3' end of the 25S rRNA contains various numbers (8-10) of tandemly arranged 180 bp subrepeats. After DNA sequencing a complex organized length heterogeneous 5' external spacer built up of different numbers of 340 bp subrepeats, each flanked by 52 bp direct repeats, is detected and described for the first time for plant ribosomal DNA repeating units. Sequences occurring in front of and within this repeated structure (elements II-IV) can be combined with the motifs P1, P2, and P3. These exhibit a strong similarity to transcription initiation sites specific for RNA polymerase I described for other plant and animal rDNA investigated to date. Transcription products complementary to the complex repeated structures are detected by hybridization to total nuclear RNA. The 9 bp element V located in fron of the first 340 bp region appears in duplicated form as a direct repeat with sequence similarity to SV40 (or RNA polymerase II) enhancer sequences.
TL;DR: Stomatal guard cell length provided a convenient and reliable method for classifying microspore-derived plants into haploid, diploid, and tetraploid groups.
Abstract: A cytological examination of 96 microspore-derived barley genotypes indicated that haploid and diploid progeny were produced in approximately equal proportions. In order to discriminate between haploid and nonhaploid derivatives, indirect ploidy evaluation techniques were examined. Stomatal guard cell length provided a convenient and reliable method for classifying microspore-derived plants into haploid, diploid, and tetraploid groups.Key words: haploid, microspore, ploidy level, guard cell, stomata, Hordeum vulgare L.
TL;DR: The frequency of microspore derived green and albino plant production was shown to be under genetic control and significant additive genetic effects were detected to indicate that the frequency of green plant regeneration may be improved by the hybridization of suitable parents.
Abstract: The genetics of barley microspore development in culture was examined by means of diallel analysis. The frequency of microspore derived green and albino plant production was shown to be under genetic control. This genotypic limitation to microspore development will limit the application of anther culture techniques to barley breeding programmes. However, significant additive genetic effects were detected for the characters measured and indicate that the frequency of green plant regeneration may be improved by the hybridization of suitable parents. Significant reciprocal differences were also detected and indicate that the direction of the cross is important in determining microspore development. An embryogenic route to green plantlet formation was observed in a number of genotypes in the diallel experiment. The implications of these findings for barley improvement and genetics are discussed.Key words: doubled haploids, barley, anther culture, microspore, embryoid.
TL;DR: The meiotic pairing behaviour of 31 interspecific combinations of tetraploid Hordeum species are reported, and Hordeum brevisubulatum is a pure autoploid with two homologous H genomes.
Abstract: The meiotic pairing behaviour of 31 interspecific combinations of tetraploid Hordeum species are reported. The autoploid H. bulbosum with the II genomic constitution has no homology to the other species. The constitution of tetraploid H. murinum is not clear, but it is not homologous to other tetraploids. Hordeum marinum is a probable autoploid (XX) but with a very strong genetic regulation of pairing. The X genome is possibly found in H. secalinum and H. capense, both of which also possess the H genome in several diploids. Hordeum fuegianum, H. tetraploidum, H. jubatum, H. brachyantherum, and H. roshevitzii are segmental alloploids all with the same two partly homoeologous genomes. Hordeum depressum is probably a segmental alloploid with the H genome and with a very strong pairing regulation. Hordeum brevisubulatum is a pure autoploid with two homologous H genomes.Key words: Hordeum, interspecific hybrids, meiosis, tetraploids.
TL;DR: Anther-derived, doubled haploid populations were obtained from two hard red winter wheats, 'Centurk' and NB88, and spontaneous doubling frequency, efficiency of colchicine treatment, and vernalization findings were reported.
Abstract: Anther-derived, doubled haploid populations were obtained from two hard red winter wheats, 'Centurk' and NB88. Spontaneous doubling frequency, efficiency of colchicine treatment, and vernalization ...
TL;DR: The presence or absence of an active NOR on the X chromosome was used to analyse the hybrid zones in two different transects of the Pyrenees, and clear clines of X NOR frequencies were observed passing from Cp.
Abstract: Two subspecies of the meadow grasshopper Chorthippus parallelus form narrow hybrid zones in the Pyrenees. We studied the patterns of chromosome divergence to evaluate their possible role in the maintenance of such hybrid zones under natural conditions. The two subspecies share some common features such as identical chromosome number, similar basic chromosome form, and the GC-rich nature of all the heterochromatic DNA. Similar positions for the nucleolar organizer region (NOR) in two pairs of autosomes were also observed. The main difference was the presence of an active NOR in the X chromosome in Cp. parallelus that was absent from Cp. erythropus. The pattern of banding by C-banding, acridine orange, and chromomycin A3 also showed the subspecific characteristics on this chromosome. The presence or absence of an active NOR on the X chromosome was used to analyse the hybrid zones in two different transects of the Pyrenees, and clear clines of X NOR frequencies were observed passing from Cp. parallelus to Cp...
TL;DR: The chromosomal locations of several genes responsible for increased malathion resistance in a laboratory-selected population of Drosophila melanogaster have been determined and these genes appear to be involved in the regulation of microsomal cytochrome P-450.
Abstract: The chromosomal locations of several genes responsible for increased malathion resistance in a laboratory-selected population of Drosophila melanogaster have been determined. These genes appear to ...
TL;DR: The geographic pattern of isozyme variation among rice varieties (Oryza sativa L.) in Asia is described based on an electrophoretic survey of 1688 accessions for 15 loci, which shows variation among indica and japonica rice shows the hilly part of continental Southeast Asia to be the region of choice.
Abstract: The geographic pattern of isozyme variation among rice varieties (Oryza sativa L.) in Asia is described based on an electrophoretic survey of 1688 accessions for 15 loci. The distribution patterns ...
TL;DR: Isozyme markers were used to develop Triticum aestivum cv.
Abstract: Isozyme markers were used to develop Triticum aestivum cv. Chinese Spring–Elytrigia elongata (= Agropyron elongatum, 2n = 14, genome E) disomic 3E and 5E addition lines. Subsequently, all possible ...
TL;DR: Studies of meiosis in diploid hybrids showed that the frequency of pairing between H. vulgare and H. bulbosum chromosomes varied between different cross combinations, although 21-chromosome cells were at the highest frequency.
Abstract: Diploid and triploid interspecific hybrids were produced from crosses between four Hordeum vulgare varieties and two diploid and two tetraploid Hordeum bulbosum genotypes. These were studied cytolo...
TL;DR: A new gametocidal gene was found in a common wheat cultivar Chinese Spring carrying the cytoplasm of Aegilops speltoides strain KU 5725 and is located on chromosome 2B, while no correlation between embryo or endosperm degeneration and chromosome breakage was observed.
Abstract: A new gametocidal gene was found in a common wheat cultivar Chinese Spring carrying the cytoplasm of Aegilops speltoides strain KU 5725 (Plant Germplasm Institute, Kyoto University). Monosomic anal...