THE RYE GENOME IN WINTER HEXAPLOID TRITICALES

1981 ◽  
Vol 23 (4) ◽  
pp. 647-653 ◽  
Author(s):  
A. G. Seal ◽  
M. D. Bennett

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.

1981 ◽  
Vol 23 (2) ◽  
pp. 281-285 ◽  
Author(s):  
Adam J. Lukaszewski ◽  
Barbara Apolinarska

Eighty-three advanced winter triticales (× Triticosecale Wittmack) derived from various initial crosses and seven unselected triticale × bread wheat (Triticum aestivum L.) F5 lines were screened for the presence of rye chromosomes. Seventy-six advanced lines had seven pairs of rye (Secale cereale L.) chromosomes, suggesting selection pressure favoring retention of the complete rye genome. The results for unselected lines suggest the operation of natural disruptive selection for parental types. Possible factors involved in yielding different chromosome constitutions in winter and spring triticales are discussed.


1982 ◽  
Vol 24 (3) ◽  
pp. 285-291 ◽  
Author(s):  
C. E. May ◽  
R. Appels

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.


1982 ◽  
Vol 24 (1) ◽  
pp. 83-92 ◽  
Author(s):  
J. P. Gustafson ◽  
M. D. Bennett

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.


1984 ◽  
Vol 26 (4) ◽  
pp. 405-408 ◽  
Author(s):  
A. E. Limin ◽  
D. B. Fowler

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.


1984 ◽  
Vol 26 (1) ◽  
pp. 46-49 ◽  
Author(s):  
J. E. Dillé ◽  
J. P. Gustafson ◽  
M. D. Bennett

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.


1982 ◽  
Vol 24 (1) ◽  
pp. 93-100 ◽  
Author(s):  
M. D. Bennett ◽  
J. P. Gustafson

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.


2018 ◽  
Vol 16 (S1) ◽  
pp. S273-S283
Author(s):  
Z. Mami-Soualem ◽  
N. Brixi ◽  
C. Beghdad ◽  
M. Belarbi

Le changement des habitudes alimentaires au cours de ces dernières années a abouti à l’apparition des maladies dites de civilisation, parmi elles le diabète sucré. Des approches diétothérapeutiques privilégient la consommation des produits céréaliers sous la forme la plus complète possible. Ce travail a pour but de tester l’efficacité des régimes expérimentaux préparés à base des grains complets des deux céréales, le sorgho (Sorghum bicolor L.) et le seigle (Secale cereale L.), sur la correction de l’hyperglycémie et des marqueurs du stress oxydant associés au diabète chez le rat mâle Wistar. Les résultats montrent que les rats diabétiques, soumis au régime seigle pendant quatre semaines, présentent une diminution significative de la glycémie qui atteint les 53,95 % à la fin de l’expérimentation, ce qui fait que leur taux en glycémie se rapproche de celui des normoglycémiques. Le sorgho blanc présente, d’une part, une diminution significative de la peroxydation lipidique intracellulaire et, d’autre part, une augmentation de l’activité de la glutathion peroxydase, la glutathion réductase ainsi que la vitamine C. Ces approches méthodologiques peuvent, en améliorant la connaissance de l’importance des céréales (fibres alimentaires solubles et des polyphénols) dans l’évolution du diabète, aboutir à des recommandations et à une éducation nutritionnelle du diabétique.


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