The effect of telomeric heterochromatin on the frequency of aneuploids in triticale (× Triticosecale)

1984 ◽  
Vol 26 (1) ◽  
pp. 46-49 ◽  
Author(s):  
J. E. Dillé ◽  
J. P. Gustafson ◽  
M. D. Bennett
Keyword(s):  
Secale Cereale ◽  
Chromosome Pair ◽  
Wheat Chromosome ◽  
Control Population ◽  
Secale Cereale L ◽  
Telomeric Heterochromatin ◽  
Triticosecale Wittmack ◽  
The Relationship

The relationship between the frequency of aneuploids and blocks of telomeric heterochromatin on rye (Secale cereale L.) chromosomes in a triticale (× Triticosecale Wittmack) background was investigated. Lines with or without blocks of telomeric heterochromatin were examined to determine the percentage of aneuploid progeny. The results showed that the amount of telomeric heterochromatin present on rye chromosomes 4R and 6R had little effect (2%) on lowering the proportion of aneuploids. When rye chromosome pair 2R was replaced by wheat chromosome 2D in the presence of chromosomes 4R and 6R lacking heterochromatin, the percentage of aneuploids increased slightly (2.7%) over that found in the control population.

THE EFFECT OF TELOMERIC HETEROCHROMATIN FROM SECALE CEREALE ON TRITICALE (X TRITICOSECALE). II. THE PRESENCE OR ABSENCE OF BLOCKS OF HETEROCHROMATIN IN ISOGENIC BACKGROUNDS

1982 ◽  
Vol 24 (1) ◽  
pp. 93-100 ◽  
Author(s):  
M. D. Bennett ◽  
J. P. Gustafson
Keyword(s):  
Secale Cereale ◽  
Chromosome Pair ◽  
Endosperm Development ◽  
Early Embryo ◽  
Kernel Weight ◽  
Yield Increase ◽  
Heterochromatin Block ◽  
Secale Cereale L ◽  
Telomeric Heterochromatin ◽  
Triticosecale Wittmack

The influence of telomeric heterochromatin blocks on early embryo and endosperm development, and on various agronomic parameters seen at maturity, was investigated using triticales (× Triticosecale Wittmack) isogenic for the presence or absence of the heterochromatin blocks on rye (Secale cereale L.) chromosomes 6R and 7R/4R. Absence of the telomeric heterochromatin blocks from the long arm of rye chromosome pair 7R/4R in DRIRA, and from the short arm of rye chromosome pair 6R in Rosner was significantly related with a lower production of aberrant endosperm nuclei and an increased kernel weight. The loss of the heterochromatin block on rye chromosome pair 7R/4R in DRIRA resulted in a significant yield increase, while there was no increase in yield when the heterochromatin block was missing from rye chromosome pair 6R in Rosner. The lack of yield increase in Rosner was apparently due to a significant decrease in fertility when the heterochromatin block on 6R was lost. The loss of the heterochromatin block on the short arm of rye chromosome 6R appears to have the same effect on aberrant endosperm nuclei production and kernel weight in two different genetic backgrounds. The rate of embryo and endosperm development showed a small but significant increase when the heterochromatin blocks were lost from both 6R and 7R/4R.

THE EFFECT OF TELOMERIC HETEROCHROMATIN FROM SECALE CEREALE ON TRITICALE (× TRITICOSECALE). I. THE INFLUENCE OF THE LOSS OF SEVERAL BLOCKS OF TELOMERIC HETEROCHROMATIN ON EARLY ENDOSPERM DEVELOPMENT AND KERNEL CHARACTERISTICS AT MATURITY

1982 ◽  
Vol 24 (1) ◽  
pp. 83-92 ◽  
Author(s):  
J. P. Gustafson ◽  
M. D. Bennett
Keyword(s):  
Secale Cereale ◽  
Positive Relationship ◽  
Strong Relationship ◽  
Endosperm Development ◽  
Kernel Weight ◽  
Test Weight ◽  
Spring Triticale ◽  
Secale Cereale L ◽  
Telomeric Heterochromatin ◽  
Triticosecale Wittmack

The relationships between telomeric heterochromatin on rye (Secale cereale L.) chromosomes, the occurrence of aberrant endosperm nuclei early during endosperm development, and kernel characteristics as seen at maturity were investigated in hexaploid spring triticale (× Triticosecale Wittmack). A positive relationship was established between the presence of telomeric heterochromatin on the short arms of rye chromosomes 4R/7R and 6R, and the production of aberrant endosperm nuclei. The removal of telomeric heterochromatin blocks from either 4R/7R or 6R significantly reduced the occurrence of nuclear instability in endosperm, and the effect of losing more than one block of telomeric heterochromatin was additive. A strong relationship was also noted between the absence of telomeric heterochromatin blocks on the short arms of rye chromosomes 4R/7R and 6R, and both higher thousand kernel weight and test weight at maturity. This relationship was also additive depending on whether one or two blocks of telomeric heterochromatin were missing. The absence of telomeric heterochromatin blocks on 4R/7R and 6R was significantly related with increased yield. The results show that amount of telomeric heterochromatin on some rye chromosomes is closely related to the occurrence of aberrant endosperm nuclei early during endosperm development and kernel characteristics at maturity.

Relationship between extract viscosity and kernel size in winter rye

1998 ◽  
Vol 78 (3) ◽  
pp. 423-427
Author(s):  
Y. T. Gan ◽  
J. G. McLeod ◽  
G. J. Scoles ◽  
G. L. Campbell
Keyword(s):  
Secale Cereale ◽  
Kernel Weight ◽  
Selection Strategy ◽  
Winter Rye ◽  
Kernel Size ◽  
Kernel Width ◽  
Secale Cereale L ◽  
The Relationship ◽  
Efficient Selection ◽  
Selection Of

Rye (Secale cereale L.) grain with low extract viscosity (EV) and superior kernel characteristics is desired when used in diets of monogastric animals. Knowledge of the relationship between EV and kernel characteristics is needed to develop an efficient selection strategy for breeding cultivars that meet the two criteria. Grains of 11 open-pollinated population varieties/lines grown in 21 environments were studied to determine the relationship between EV and kernel weight (KWT) among genotypes and environmental effects. Grains of eight out of the eleven varieties/lines were screened into five kernel-size categories, <2.0, 2.0–2.4, 2.4–2.8, 2.8–3.2, >3.2 mm in kernel width, to determine the relationship between EV and kernel width within a genotype. EV was a linear function of KWT; high KWT is indicative of low EV. The degree of the relationship was affected by environment. For example, grains grown at Swift Current had a stronger relationship between EV and KWT than those from Lacombe (b = −1.67 vs. −0.31). For the grain from Swift Current, 60% of variability in EV was attributable to KWT, while for the grain from Lacombe only ≈ 20% of variability in EV was explainable by KWT. Among the various kernel-width categories within a genotype, 60 to 98% of variability in EV was attributable to kernel width, with some genotypes responding to a greater degree than others. In development of winter rye cultivars low in extract viscosity, breeders could combine kernel weight/width into the selection strategy to enhance the selection progress or use kernel weight/width as a reference in selection of extract viscosity trait. Key words: Pentosans, arabinoxylans, kernel weight, Secale cereale

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 INHERITANCE OF RYE CHROMOSOMES IN EARLY GENERATIONS OF TRITICALE × WHEAT HYBRIDS

1982 ◽  
Vol 24 (3) ◽  
pp. 285-291 ◽  
Author(s):  
C. E. May ◽  
R. Appels
Keyword(s):  
Triticum Aestivum ◽  
Secale Cereale ◽  
Second Generation ◽  
Triticum Aestivum L ◽  
Chromosome Translocation ◽  
Agronomic Characters ◽  
Secale Cereale L ◽  
Wheat Hybrids ◽  
Triticosecale Wittmack

Triticales (× Triticosecale Wittmack) are being employed as a source of rye (Secale cereale L.) chromatin for the introduction of specific agronomic characters into wheat (Triticum aestivum L. em Thell.). The rye chromosomes present in plants of the first and second generations of a backcrossing program have been identified using a radioactive in situ probe which hybridizes to specific sites on the rye chromosomes. We show that homologous pairs of rye chromosomes are present by the second generation which should thereby ensure their eventual substitution. Furthermore, rye telosomes and a wheat-rye chromosome translocation involving 5RL were also observed as possibly useful modifications of the rye chromosomes in this breeding program.

Spontaneous somatic transfer of a segment from a wheat addition chromosome into the rye genome

Genome ◽  
1990 ◽  
Vol 33 (6) ◽  
pp. 794-797 ◽  
Author(s):  
G. Melz ◽  
V. Thiele
Keyword(s):  
Chromosome Pair ◽  
Wheat Chromosome ◽  
Centromeric Heterochromatin ◽  
Glutamate Oxaloacetate Transaminase ◽  
Specific Chromosome ◽  
Chromosome Addition ◽  
B Genome ◽  
Univalent Pair ◽  
Telomeric Heterochromatin ◽  
Chromosome 3B

Wheat chromosome 3B when added to the rye genome causes resistance to powdery mildew of rye (Erysiphe graminis DC. f.sp. secalis Marchal) as the result of the action of the gene Rpm1. Wheat chromosome 3B also carries the gene Got-B3 for glutamate oxaloacetate transaminase. In two independent, vegetatively reproduced additions of 3B to rye, the extra wheat chromosome appeared to have been lost spontaneously, but both genes were still present. The rye chromosome into which the genes had been transferred could not be identified. Chromosome 3R appeared to be morphologically unchanged, no telomeric heterochromatin normally present in any rye chromosome had disappeared, and no wheat B-genome centromeric heterochromatin was observed. At meiosis the chiasma frequency was reduced, resulting in the frequent formation of one univalent pair, and occasionally two univalent pairs. No specific chromosome pair was preferentially involved. The wheat genes could not be transferred to the progeny by selfing nor by reciprocal back-crossing, but gametes without these genes were functional. The plants were semisterile.Key words: wheat chromosome addition, rye, somatic translocation, univalents, mildew resistance.

Timing and rate of genome variation in triticale following allopolyploidization

Genome ◽  
2006 ◽  
Vol 49 (8) ◽  
pp. 950-958 ◽  
Author(s):  
Xue-Feng Ma ◽  
J Perry Gustafson
Keyword(s):  
Sequence Variation ◽  
Genomic Sequence ◽  
Chromosome Doubling ◽  
Genomic Variation ◽  
Key Factors ◽  
Genome Variation ◽  
Triticum Spp ◽  
Secale Cereale L ◽  
Triticosecale Wittmack ◽  
The Relationship

The timing and rate of genomic variation induced by allopolyploidization in the intergeneric wheat-rye (Triticum spp. – Secale cereale L.) hybrid triticale (× Triticosecale Wittmack) was studied using amplified fragment length polymorphism (AFLP) analyses with 2 sets of primers, EcoRI–MseI (E–M) and PstI–MseI (P–M), which primarily amplify repetitive and low-copy sequences, respectively. The results showed that allopolyploidization induced genome sequence variation in triticale and that a great degree of the genome variation occurred immediately following wide hybridization. Specifically, about 46.3% and 36.2% of the wheat parental band loss and 74.5% and 68.4% of the rye parental band loss occurred in the F1 hybrids (before chromosome doubling) for E–M and P–M primers, respectively. The sequence variation events that followed chromosome doubling consisted of continuous modifications that occurred at a very small rate compared with the rate of variation before chromosome doubling. However, the rate of sequence variation involving the rye parental genome was much higher in the first 5 generations following chromosome doubling than in any subsequent generation. Surprisingly, the highest rate of rye genomic variation occurring after chromosome doubling was in C3 or later, but not in C1. The data suggested that the cytoplasm and the degree of the relationship between the parental genomes were the key factors in determining the direction, amount, timing, and rate of genomic sequence variation occurring during intergeneric allopolyploidization.Key words: genome evolution, sequence variation, allopolyploid, triticale, AFLP.

THE RYE GENOME IN WINTER HEXAPLOID TRITICALES

1981 ◽  
Vol 23 (4) ◽  
pp. 647-653 ◽  
Author(s):  
A. G. Seal ◽  
M. D. Bennett
Keyword(s):  
Secale Cereale ◽  
Selection Pressure ◽  
Divergent Selection ◽  
Environmental Adaptation ◽  
Dna Amount ◽  
Selection Pressures ◽  
Diploid Genome ◽  
Cereal Grain ◽  
Secale Cereale L ◽  
Triticosecale Wittmack

In eight winter triticales (× Triticosecale Wittmack) chosen from the Cambridge crossing program all seven rye (Secale cereale L.) chromosomes were present. However, a number of rye chromosomes showed an obvious reduction in the size of C-bands at one or more telomeres, compared with normal rye. In two lines the C-band at the short arm telomere of 2R was obviously larger than normal in rye. Comparison of these results with those published for spring triticales suggests that divergent selection pressures may determine the number and structure of rye chromosomes in winter and spring lines. In particular it is suggested that the differences may represent environmental adaptation and reflect selection pressure on the rye genome in triticale to conform to the cline for DNA amount per diploid genome on latitude previously described in cereal grain crops.

The effect of cytoplasm on cold hardiness in alloplasmic rye (Secale cereale L.) and triticale

1984 ◽  
Vol 26 (4) ◽  
pp. 405-408 ◽  
Author(s):  
A. E. Limin ◽  
D. B. Fowler
Keyword(s):  
Triticum Aestivum ◽  
Secale Cereale ◽  
Cold Hardiness ◽  
Triticum Aestivum L ◽  
Complete Suppression ◽  
Cytoplasmic Effects ◽  
Secale Cereale L ◽  
Triticosecale Wittmack ◽  
Octoploid Triticale ◽  
Wheat Parent

Many changes occur within the cytoplasm of plant cells during cold acclimation. However, the cause and effect relationship between cytoplasmic response to low temperature and the development of cold hardiness in cells has been difficult to determine. This study considered the importance of rye (Secale cereale L.) and wheat (Triticum aestivum L. and Triticum tauschii (Coss.) Schmal.) cytoplasmic effects in conditioning plant cold hardiness. The cold hardiness of octoploid triticale (× Triticosecale Wittmack) produced from hardy rye and nonhardy wheat was similar to that of the wheat parent, demonstrating a complete suppression of the rye cold hardiness genes. Similar observations were made for wheat – rye amphiploids from reciprocal crosses, indicating that this suppression was not due to cytoplasmic effects. It is more probable that, because the cold hardiness of octoploid triticale approximates that of the wheat parent, the cold hardiness potential of the rye genome is suppressed by a gene or genes in the wheat complement. The cold hardiness of alloplasmic rye with T. tauschii cytoplasm was similar to that of the rye parent indicating that the cold hardiness genes of rye have normal expression in the T. tauschii cytoplasm. Based on observations made in these two studies, it was concluded that the cytoplasm has little direct effect on cold hardiness, or on the nuclear expression of cold hardiness.Key words: cold hardiness, cytoplasm, Triticum aestivum L., triticale, alloplasmic rye.

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