scholarly journals PAIRING COMPETITION BETWEEN IDENTICAL AND HOMOLOGOUS CHROMOSOMES IN AUTOTETRAPLOID RYE. I. SUBMETACENTRIC CHROMOSOMES

Genetics ◽  
1985 ◽  
Vol 111 (4) ◽  
pp. 933-944
Author(s):  
J Orellana ◽  
J L Santos
Keyword(s):  
Genetic Control ◽  
Secale Cereale ◽  
Inbred Lines ◽  
Meiotic Pairing ◽  
Homologous Chromosomes ◽  
Partner Exchange ◽  
Pairing Behavior ◽  
Chromosome 1R ◽  
Heterochromatin Content

ABSTRACT Meiotic pairing preferences between identical and homologous but not identical chromosomes were analyzed in ten induced tetraploid/diploid chimaeral rye plants (Secale cereale) heterozygous for telomeric heerochromatin C-bands in both arms of chromosome 1R. These plants were the progeny of two crosses between only one plant of cv. Petkus, used as male, and two plants of the inbred lines E and R, respectively. Different pairing preferences for chromosome 1R were found: (1) between plants, (2) between chromosome arms within the same plant and (3) between bivalents and multivalents within the same plant. The possible influence in the preferences of several factors such as differences in C-heterochromatin content in the chromosomes analyzed, specific genetic control and independence in pairing behavior between both arms and partner exchange is discussed.

Evidence of nonchiasmate bonds at metaphase I in inbred rye

1984 ◽  
Vol 26 (4) ◽  
pp. 409-414 ◽  
Author(s):  
M. C. Cermeño ◽  
J. Orellana ◽  
J. R. Lacadena
Keyword(s):  
Secale Cereale ◽  
Chiasma Frequency ◽  
Meiotic Pairing ◽  
Secale Cereale L ◽  
Chromosome 1R ◽  
Metaphase I

The loss of bound chromosome arms through early, middle, and late metaphase I has been analyzed in a plant of inbred rye (Secale cereale L.) heterozygous for a terminal heterochromatic C-band of the long arm of chromosome 1R. From the increase in the number of univalent pairs due to bound arm loss, and from the comparison between the frequencies of bound arms at metaphase I and recombinant chromosomes at anaphase I, it is concluded that some of the chromosome bonds appearing at metaphase I are actually nonchiasmate associations that can be considered as remnants of prophase pairing. Conclusions concerning recombination obtained solely from the analysis of chiasma frequency measured as bound arms may be invalid.Key words: inbred rye, C-heterochromatin, meiotic pairing, nonchiasmate bonds.

scholarly journals PAIRING COMPETITION BETWEEN IDENTICAL AND HOMOLOGOUS CHROMOSOMES IN RYE AND GRASSHOPPERS

Genetics ◽  
1983 ◽  
Vol 104 (4) ◽  
pp. 677-684
Author(s):  
J L Santos ◽  
J Orellana ◽  
R Giraldez
Keyword(s):  
Secale Cereale ◽  
Banding Pattern ◽  
Chromosome Pair ◽  
Meiotic Pairing ◽  
Homologous Pairing ◽  
Eyprepocnemis Plorans ◽  
Homologous Chromosomes ◽  
Random Pairing ◽  
Structural Differences ◽  
Telomeric Heterochromatin

ABSTRACT Meiotic pairing preferences between identical and homologous but not identical chromosomes were analyzed in spontaneous tetraploid/diploid chimeras of three male grasshoppers (Eyprepocnemis plorans) whose chromosome pair 11 were heterozygous for C-banding pattern and in four induced tetraploid/diploid chimaeral rye plants (Secale cereale) heterozygous for telomeric heterochromatin C-bands in chromosomes 1R and 2R. In the grasshoppers, a preference for identical over homologous pairing was observed, whereas in rye both a preference for homologous rather than identical pairing and random pairing between the four chromosomes of the set was found. From the results in rye, it can be deduced that pairing preferences do not depend exclusively on the similarities between chromosomes involved. It is suggested that genotypic or cryptic structural differences between the homologous chromosomes of each pair analyzed might be responsible for the pairing preferences found. This hypothesis can also explain the results obtained in grasshoppers, although the possibility of premeiotic association cannot be excluded in this material.

The ffs Allele Conditions Flower Stem Fasciation in Red Beet

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 527f-528
Author(s):  
I.L. Goldman
Keyword(s):  
Genetic Control ◽  
Inbred Line ◽  
Goodness Of Fit ◽  
Female Parent ◽  
Inbred Lines ◽  
Chi Square ◽  
Recessive Character ◽  
Variable Expression ◽  
Red Beet ◽  
Flower Stem

A fasciated flower stem character arose spontaneously during development of the red beet (Beta vulgaris L.) inbred line W411. The fasciated character is manifest by a flattened flower stem with petioles coalesced into a twisted, ribbonlike appearance. No fasciation is present in the vegetative stem or petioles. An inheritance study was conducted to determine the genetic control of flower stem fasciation. The inbred line W411 was used both as a male and female parent in crosses with four red beet inbred lines. Segregating progenies in both the BC1 and F2 generations were developed and scored for the fasciated flower stem character. Variable expression of the fasciated flower stem phenotype was observed in these progenies; however, the presence of flattened flower stems at the stem/hypocotyl junction was unequivocal. Chi-square goodness-of-fit tests in both the BC1 and F2 generations did not deviate significantly from expected ratios for a monogenic recessive character for each genetic background. No reciprocal differences were detected for any cross in this group of four inbred lines, which suggests the lack of maternal effect for the fasciated character. The symbol ffs is proposed to describe the genetic control of the fasciated flower stem phenotype.

Effect of the Pairing Gene Ph1 and Premeiotic Colchicine Treatment on Intra- and Interchromosome Pairing of Isochromosomes in Common Wheat

Genetics ◽  
1998 ◽  
Vol 150 (3) ◽  
pp. 1199-1208 ◽  
Author(s):  
Juan M Vega ◽  
Moshe Feldman
Keyword(s):  
Common Wheat ◽  
Homologous Chromosome ◽  
Colchicine Treatment ◽  
Crossing Over ◽  
Meiotic Pairing ◽  
Factors Affecting ◽  
Homologous Chromosomes ◽  
Polyploid Wheat ◽  
Main Gene ◽  
Ph1 Gene

Abstract The analysis of the pattern of isochromosome pairing allows one to distinguish factors affecting presynaptic alignment of homologous chromosomes from those affecting synapsis and crossing-over. Because the two homologous arms in an isochromosome are invariably associated by a common centromere, the suppression of pairing between these arms (intrachromosome pairing) would indicate that synaptic or postsynaptic events were impaired. In contrast, the suppression of pairing between an isochromosome and its homologous chromosome (interchromosome pairing), without affecting intrachromosome pairing, would suggest that homologous presynaptic alignment was impaired. We used such an isochromosome system to determine which of the processes associated with chromosome pairing was affected by the Ph1 gene of common wheat—the main gene that restricts pairing to homologues. Ph1 reduced the frequency of interchromosome pairing without affecting intrachromosome pairing. In contrast, intrachromosome pairing was strongly reduced in the absence of the synaptic gene Syn-B1. Premeiotic colchicine treatment, which drastically decreased pairing of conventional chromosomes, reduced interchromosome but not intrachromosome pairing. The results support the hypothesis that premeiotic alignment is a necessary stage for the regularity of meiotic pairing and that Ph1 relaxes this alignment. We suggest that Ph1 acts on premeiotic alignment of homologues and homeologues as a means of ensuring diploid-like meiotic behavior in polyploid wheat.

THE INHERITANCE OF RESISTANCE IN RYE TO Puccinia recondita f. sp. secalis and f. sp. tritici

1984 ◽  
Vol 64 (3) ◽  
pp. 511-519 ◽  
Author(s):  
G. L. C. MUSA ◽  
P. L. DYCK ◽  
D. J. SAMBORSKI
Keyword(s):  
Disease Resistance ◽  
Leaf Rust ◽  
Secale Cereale ◽  
Single Gene ◽  
Inbred Lines ◽  
Puccinia Recondita ◽  
Wheat Leaf Rust ◽  
Susceptible Parent ◽  
Seedling Resistance ◽  
Wheat Leaf

The inheritance of seedling resistance to isolate RLR 213/78 of rye leaf rust (Puccinia recondita f. sp. secalis) and race 30 of wheat leaf rust (P. recondita f. sp. tritici Rob.) was investigated in six inbred lines of rye (Secale cereale). Inbred line UM8116 was used as the susceptible parent in crosses. Inbred lines UM8003, UM8071 and UM8301 each have a single gene and UM8336 and UM8340 each have two genes for resistance to rye leaf rust. For resistance to wheat leaf rust UM8071 has a single gene, UM8003 and UM8340 each have two genes and UM8301 and UM8336 each have three genes. UM8295 is heterogeneous for reaction to both rusts. One of the genes in UM8340 may condition resistance to both rusts. The genes for resistance to RLR 213/78 appear to be independently inherited while some of the genes conferring resistance to race 30 may be identical or very closely linked. The potential of rye as a source of disease resistance for wheat and triticale improvement is discussed.Key words: Secale cereale, disease resistance, wheat leaf rust

Inferences from genetical evidence on the course of meiotic chromosome pairing in plants

1977 ◽  
Vol 277 (955) ◽  
pp. 313-326 ◽  
Keyword(s):  
Chromosome Pairing ◽  
Developmental Stages ◽  
Meiotic Chromosome ◽  
Critical Assessment ◽  
Gene Control ◽  
Meiotic Pairing ◽  
Homologous Chromosomes ◽  
Meiotic Chromosome Pairing ◽  
Combined Use ◽  
Or Gene

Meiotic chromosome pairing is a process that is amenable to genetic and experimental analysis. The combined use of these two approaches allows for the process to be dissected into several finite periods of time in which the developmental stages of pairing can be precisely located. Evidence is now available, in particular in plants, that shows that the pairing of homologous chromosomes, as observed at metaphase I, is affected by events occurring as early as the last premeiotic mitosis; and that the maintenance of this early determined state is subsequently maintained by constituents (presumably proteins) that are sensitive to either colchicine, temperature or gene control. A critical assessment of this evidence in wheat and a comparison of the process of pairing in wheat with the course of meiotic pairing in other plants and animals is presented.

scholarly journals DISTRIBUTION OF NONSTRUCTURAL VARIATION ALONG THREE CHROMOSOME ARMS BETWEEN WHEAT CULTIVARS CHINESE SPRING AND CHEYENNE

Genetics ◽  
1984 ◽  
Vol 106 (2) ◽  
pp. 309-324
Author(s):  
Anne Crossway ◽  
Jan Dvořák
Keyword(s):  
Chinese Spring ◽  
Continuous Distribution ◽  
Inbred Lines ◽  
Wheat Cultivars ◽  
Chromosome Variation ◽  
Homologous Chromosomes ◽  
Ring Bivalents ◽  
Chromosome Arm ◽  
Parental Inbred ◽  
The Mean

ABSTRACT Metaphase I (MI) pairing of wheat homologous chromosomes is usually reduced in hybrids between cultivars relative to the parental inbred lines. Previous work suggested that this phenomenon is caused by polymorphism in nucleotide sequences (nonstructural chromosome variation) among wheat cultivars. The present work investigated the distribution of this variation along three selected chromosome arms between cultivars Chinese Spring and Cheyenne. Chinese Spring ditelosomics 3Aq, 6Ap and 6Bp were crossed with disomic substitutions of Cheyenne chromosomes 3A, 6A and 6B in Chinese Spring, respectively. The resulting F1 plants, called substituted monotelodisomics, were crossed with the respective Chinese Spring monosomics, producing potentially "recombinant" substituted monosomics. When these "recombinant" chromosomes were combined with the parental Chinese Spring telosomes, marked reductions in mean telosome-pairing frequency were found compared with the corresponding Chinese Spring monotelodisomics. The mean pairing frequencies of the "recombinant" chromosomes showed a continuous distribution between those of the substituted and Chinese Spring monotelodisomics. The results suggest that the nonstructural variation that reduces MI pairing between chromosomes of different wheat cultivars is not localized in a specific site but distributed along each chromosome arm. Little variation was found among monotelodisomics for either the number of ring bivalents per cell or the number of univalents other than those constituting the heteromorphic pair. This implies that the reductions in MI pairing between the Cheyenne and Chinese Spring chromosomes are caused by something residing within these specific chromosomes that does not affect the pairing of the remaining Chinese Spring chromosomes in the same cell. Furthermore, the absence of parental types among the "recombinant"-substituted monotelodisomics suggests that the sequences involved in the variation studied here are capable of converting heterohomologous chromosomes to something intermediate in nature in the span of only a single generation.

THE GENETICS OF FERTILITY RESTORATION IN CYTOPLASMIC MALE-STERILE RYE

1979 ◽  
Vol 21 (3) ◽  
pp. 417-422 ◽  
Author(s):  
G. J. Scoles ◽  
L. E. Evans
Keyword(s):  
Secale Cereale ◽  
Fertility Restoration ◽  
Inbred Lines ◽  
Male Sterile ◽  
Male Sterile Line ◽  
Cytoplasmic Male Sterile ◽  
Restorer Genes ◽  
Secale Cereale L ◽  
Partial Fertility

Three inbred lines of rye (Secale cereale L.) known to be capable of restoring fertility to a cytoplasmic male-sterile line were crossed with the sterile line. The proportions of male fertile, partially male fertile and male sterile plants in F2 and backcross progenies indicated that three dominant restorer genes were present in each line. These were designated Rf1, Rf2 and Rf3, their relative expressivity was Rf1>Rf2>Rf3. Expressivity was dependent upon environment. Partial fertility occurred when certain genotypes carried two of the three alleles as dominant, but was dependent upon genotype and environment.

Can abortive early homologous associations promote increased crossing-over in an adjacent rearranged segment?

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 469-472 ◽  
Author(s):  
Marjorie P. Maguire
Keyword(s):  
Crossing Over ◽  
Meiotic Pairing ◽  
Pairing Behavior ◽  
Chromosome Segments

Meiotic pairing behavior of rearranged chromosome segments is compared across an informative series of combinations. The question is raised whether the simplest explanation for some peculiar findings may include a sequence of synaptic precursor events at leptotene or zygotene, the course of which may eventually strongly affect crossover frequency.Key words: meiosis, synapsis, crossing-over, rearrangement.

scholarly journals Mapping of resistance genes to brown rust in 1R chromosome of rye (Secale cereale L.)

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 588-589
Author(s):  
O.A. Baranova ◽  
A.P. Dmitriev ◽  
A.V. Voylocov ◽  
O.V. Solodukhina
Keyword(s):  
Resistance Genes ◽  
Secale Cereale ◽  
Segregation Analysis ◽  
Recombination Frequency ◽  
Brown Rust ◽  
Isozyme Locus ◽  
Secale Cereale L ◽  
Chromosome 1R

Five resistance genes to single-pustule isolates Nos. 12, 81,108 and 7 of brown rust were mapped on 1R chromosome of rye using two different F<sub>2</sub> populations. Under segregation analysis it was found linkage between genes controlling resistance to single-pustule isolates No. 12, 81, 108 and 25 and isozyme locus Prx7, which to be localized on chromosome 1R. The recombination frequencies are 0.32, 0.28, 0.29 and 0.32 correspondingly. Also we were found linkage between Prx7 and gene, controlling resistance to single-pustule isolate No. 7. Recombination frequency in this case was equal 0.10 and 0.29 in dependence on analyzing hybrids.

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