The cytogenetics of the differences between some Secale species

1955 ◽  
Vol 46 (3) ◽  
pp. 377-383 ◽  
Author(s):  
Ralph Riley
Keyword(s):  
Secale Cereale ◽  
Chromosome Structure ◽  
Plant Morphology ◽  
Structural Condition ◽  
Evolutionary Significance ◽  
Seed Parent ◽  
Ear Morphology ◽  
The Cross ◽  
Fourth Pair

1. The seed of crosses of Secale cereale with S. montanum and S. dalmaticum germinated only when S. cereale was the seed parent.2. S. cereale was found to differ from S. montanum and S. dalmaticum by two large translocations involving three pairs of chromosomes, and a small translocation involving a fourth pair. The fertility of the F1 plants was low, and in ear morphology and perennial habit they were similar to the S. montanum and S. dalmaticum parents.3. S. montanum and S. dalmaticum were found to be similar in gross chromosome structure and their hybrids were phenotypically intermediate and fertile.4. The F2 of the cross S. cereale x S. dalmaticum consisted of three types, in terms of chromosome structural condition and plant morphology, those like one or other parent and those like the F1.5. The genetic and evolutionary significance of this situation is discussed, together with the problem of the fixation of translocations in populations.

scholarly journals Genetical and Cytological Studies in Hybrid Roses

1924 ◽  
Vol 1 (4) ◽  
pp. 557-570
Author(s):  
KATHLEEN B. BLACKBURN ◽  
J. W. HESLOP HARRISON
Keyword(s):  
Chromosome Number ◽  
Pollen Parent ◽  
Egg Cell ◽  
Generative Nucleus ◽  
Seed Parent ◽  
Reciprocal Crosses ◽  
The Cross

1. Rosa Sabini and R. Wilsoni are reciprocal crosses between R. pimpinellifolia and some Tomentosa microgene. 2. Rosa pimpinellifolia is a balanced tetraploid, both the egg cell and the generative nucleus possessing 14 chromosomes. 3. The Tomentosa microgenes are unbalanced pentaploids, the microspores, when functional, carrying 7 chromosomes in their nuclei, and the egg cells 28. 4. Reciprocal crosses between R. pimpinellifolia and tomentosa forms should not therefore agree in chromosome complements. With pimpinellifolia as seed parent the cross should have 14 + 7 ( = 21) in its somatic nuclei, and with the same plant as pollen parent the number should be 28 + 14 ( = 42). 5. R. Wilsoni undoubtedly has R. pimpinellifolia as seed parent, yet its chromosome number is 42. 6. It has, therefore, like Primula Kewensis, doubled its original complement. 7. In doing so, again like that hybrid, it has attained fertility.

Hybridization of a Rocky Mountain fir (Abiesconcolor) and a Mexican fir (Abiesreligiosa)

1988 ◽  
Vol 18 (5) ◽  
pp. 640-643 ◽  
Author(s):  
J. B. St. Clair ◽  
W. B. Critchfield
Keyword(s):  
Morphological Characteristics ◽  
Rocky Mountain ◽  
Interspecific Crosses ◽  
Herbarium Specimens ◽  
Seed Parent ◽  
White Fir ◽  
The Cross ◽  
Monoterpene Composition ◽  
Germinable Seed ◽  
Putative Hybrids

Interspecific crosses of Abiesreligiosa (HBK.) Schlecht. & Cham, (oyamel) with Abiesconcolor (Gord. & Glend.) Lindl. ex Hildebr. var. concolor (white fir) and Abiesmagnifica A. Murr. (California red fir) were undertaken to explore the relationships between these species. The cross with A. magnifica produced no germinable seed, but many sound seeds were produced from the cross with A. concolor. These were sown in the nursery in 1968 and outplanted in 1970. In 1983, morphological characteristics of seven putative hybrids were compared with those of the A. concolor seed parent, herbarium specimens of A. religiosa, and published descriptions of both species. In addition, monoterpene composition of the putative hybrids was compared with that of the seed parent and two unrelated A. religiosa trees from the same provenance as the pollen parent. Results indicate that the putative hybrids are indeed hybrids between A. concolor and A. religiosa. This finding suggests that either taxonomic sections are not separated by reproductive barriers in Abies (as they are in Pinus) or that earlier classifications should be reconsidered.

Genetics and cytology of unreduced gametes in cultivated rye (Secale cereale L.)

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 635-638 ◽  
Author(s):  
T. Lelley ◽  
A. A. Mahmoud ◽  
V. Lein
Keyword(s):  
Key Words ◽  
Genetic Control ◽  
Inbred Line ◽  
Secale Cereale ◽  
Chiasma Frequency ◽  
Unreduced Gametes ◽  
Recessive Trait ◽  
Secale Cereale L ◽  
The Cross

An inbred genotype of cultivated rye was found that produces unreduced gametes in a very regular fashion. In the cross progeny of this line with another inbred line, which did not show unreduced gametes, the inheritance of this phenomenon was studied. The formation of unreduced gametes appears to be a recessive trait controlled by more than one gene. Chiasma frequency in 4n PMCs is exactly twice that in 2n PMCs. In first metaphase of 4n PMCs only bivalents (no multivalents) were seen. The possible mechanism leading to unreduced gametes and its evolutionary implications are discussed. Key words: rye, unreduced gametes, polyploidy, genetic control, chiasma frequency.

Unilateral seed failure after reciprocal crosses of Secale cereale with Secale africanum

1975 ◽  
Vol 53 (9) ◽  
pp. 929-932 ◽  
Author(s):  
H. James Price
Keyword(s):  
Secale Cereale ◽  
Reciprocal Cross ◽  
Agar Medium ◽  
Endosperm Development ◽  
Hybrid Plant ◽  
Seed Parent ◽  
Secale Africanum ◽  
Ultimate Cause ◽  
Viable Seeds ◽  
Excised Embryos

In crosses between Secale cereale and Secale africanum, viable seeds are formed when S. cereale is the seed parent. No viable seeds develop from the reciprocal cross. Histological comparisons of developing S. africanum × S. cereale seeds with those of S. africanum indicated that the ultimate cause of seed failure was abnormal endosperm development. The endosperm became cellular and contained small starch grains in a few cells. The endosperm cells progressively collapsed and deteriorated. No abnormalities in maternal tissues were observed. Excised embryos were cultured on nutrient-supplemented agar medium. One of these grew into a vigorous hybrid plant when transferred to soil, which thus indicated that the embryos from this cross are potentially viable.

COMPARISON OF CULTIVAR HYBRIDS AND BLENDS WITH PURE CULTIVARS IN CRESTED WHEATGRASS

1979 ◽  
Vol 59 (4) ◽  
pp. 1019-1023 ◽  
Author(s):  
R. P. KNOWLES
Keyword(s):  
Agropyron Cristatum ◽  
Pollen Parent ◽  
Seed Parent ◽  
Average Yield ◽  
Crested Wheatgrass ◽  
The Cross

Four strains of crested wheatgrass were allowed to interpollinate in pairs to form hybrids which were subsequently compared with parents and seed blends of parents for hay production. Average yield gains of 2–3% were obtained for hybrids relative to parental averages while that of blends was 0–1%. Certain combinations gave somewhat greater gains such as 4–8% for the cross Summit × Nordan relative to the higher yielding Summit parent. The degree of hybridization varied from 0 to 56% with an average of 16% in the first set of crosses and 21% in the second set. The. colchicine-induced tetraploid of Agropyron cristatum (L.) Gaertn. as seed parent showed little crossing with the natural tetraploid A. desertorum (Fisch.) Schult., but 12–34% when used as the pollen parent.

Chromosome structure and pairing preferences in autotetraploid rye (Secale cereale)

Genome ◽  
1994 ◽  
Vol 37 (5) ◽  
pp. 784-793 ◽  
Author(s):  
G. Jenkins ◽  
R. Chatterjee
Keyword(s):  
Electron Microscopy ◽  
Secale Cereale ◽  
Homologous Chromosome ◽  
Chromosome Structure ◽  
Structural Similarity ◽  
The Other ◽  
Whole Mount ◽  
Structural Divergence ◽  
Surface Spread ◽  
Pairing Behaviour

The influence of chromosome structure upon pairing behaviour during meiosis was investigated by comparing four autotetraploid genotypes of rye (Secale cereale) containing homologous chromosome sets with different degrees of structural similarity. The series provided a range of genotypes that, at one extreme, contained structurally identical chromosome sets and, at the other extreme, sets that are certainly more heterozygous in the genic sense and probably also more diverse from a purely structural viewpoint. Relative frequencies of pairing configurations at meiotic prophase and metaphase I were compared by electron microscopy of whole-mount surface-spread synaptonemal complex complements and light microscopy of squash preparations. Despite unexpectedly low quadrivalent frequencies over all four genotypes, higher mean bivalent frequencies appeared to be associated with greater homologue diversity. In other words, greater structural divergence between chromosome sets appears to facilitate more efficient discrimination between homologous and identical chromosomes that drives the formation of bivalents. Statistical comparisons were not able to confirm in some cases the significance of the observed pattern of pairing behaviour.Key words: autotetraploid, rye, synapsis, chiasmata.

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Some Biological Applications of High Voltage Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 298-299
Author(s):  
Hans Ris
Keyword(s):  
High Voltage ◽  
Chromosome Structure ◽  
Nerve Fibers ◽  
Good Resolution ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
University Of Wisconsin ◽  
High Voltage Electron ◽  
One Year ◽  
The University

The High Voltage Electron Microscope Laboratory at the University of Wisconsin has been in operation a little over one year. I would like to give a progress report about our experience with this new technique. The achievement of good resolution with thick specimens has been mainly exploited so far. A cold stage which will allow us to look at frozen specimens and a hydration stage are now being installed in our microscope. This will soon make it possible to study undehydrated specimens, a particularly exciting application of the high voltage microscope.Some of the problems studied at the Madison facility are: Structure of kinetoplast and flagella in trypanosomes (J. Paulin, U. of Georgia); growth cones of nerve fibers (R. Hannah, U. of Georgia Medical School); spiny dendrites in cerebellum of mouse (Scott and Guillery, Anatomy, U. of Wis.); spindle of baker's yeast (Joan Peterson, Madison) spindle of Haemanthus (A. Bajer, U. of Oregon, Eugene) chromosome structure (Hans Ris, U. of Wisconsin, Madison). Dr. Paulin and Dr. Hanna are reporting their work separately at this meeting and I shall therefore not discuss it here.

Structures Resembling Striated Rootlets in Oocytes

1972 ◽  
Vol 30 ◽  
pp. 124-125
Author(s):  
Valerie V. Ernst
Keyword(s):  
Golgi Complex ◽  
Fibrous Structure ◽  
Oocyte Development ◽  
The Cross

During the earliest stage of oocyte development in the limpet, Acmea scutum, Golgi complexes are small, few and randomly dispersed in the cytoplasm. As growth proceeds, the Golgi complexes increase in size and number and migrate to the periphery of the cell. At this time, fibrous structures resembling striated rootlets occur associated with the Golgi complexes. Only one fibrous structure appears to be associated with a Golgi complex.The fibers are periodically cross banded with an average of 4 dense fibrils and 6 lighter fibrils per period (Fig. 1). The cross fibrils have a center to center spacing of about 7 run which appears to be the same as that of the striated rootlets of the gill cilia in this animal.

Energy Distribution in Electron Beams

1972 ◽  
Vol 30 ◽  
pp. 568-569
Author(s):  
Tamotsu Ohno
Keyword(s):  
Electron Beam ◽  
Energy Distribution ◽  
Cross Section ◽  
Integral Curve ◽  
Electron Beams ◽  
Electron Gun ◽  
Angular Divergence ◽  
Apparent Increase ◽  
Integral Width ◽  
The Cross

The energy distribution in an electron; beam from an electron gun provided with a biased Wehnelt cylinder was measured by a retarding potential analyser. All the measurements were carried out with a beam of small angular divergence (<3xl0-4 rad) to eliminate the apparent increase of energy width as pointed out by Ichinokawa.The cross section of the beam from a gun with a tungsten hairpin cathode varies as shown in Fig.1a with the bias voltage Vg. The central part of the beam was analysed. An example of the integral curve as well as the energy spectrum is shown in Fig.2. The integral width of the spectrum ΔEi varies with Vg as shown in Fig.1b The width ΔEi is smaller than the Maxwellian width near the cut-off. As |Vg| is decreased, ΔEi increases beyond the Maxwellian width, reaches a maximum and then decreases. Note that the cross section of the beam enlarges with decreasing |Vg|.

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