TRISOMICS OF AVENA STRIGOSA

1975 ◽  
Vol 17 (2) ◽  
pp. 151-166 ◽  
Author(s):  
Tibor Rajhathy
Keyword(s):  
Transmission Rate ◽  
Extra Chromosome ◽  
Chromosome Length ◽  
Chromosome Morphology ◽  
Balance Theory ◽  
Primary Trisomics ◽  
Qualitative And Quantitative ◽  
Dosage Effects ◽  
Avena Strigosa ◽  
Small Seed

A set of seven primary trisomics and seven derived types were produced in Avena strigosa Schreb., a diploid oat species. Each trisomic type had a distinct phenotype. The primary trisomics were identified on the basis of plant and chromosome morphology. Although fertility (seed-set) and the frequency of transmission of the extra chromosome varied among selfed progenies of the various trisomics, each trisomic can be maintained. The trisomics occurred at a higher frequency in small seed fractions than in samples of large seeds. No straightforward relationship was apparent between chromosome length and trivalent formation but some association between trivalent formation and transmission rate was observed.Several qualitative and quantitative traits were compared between the primary telotri-somics, between these and the disomic and between opposite arm telotrisomics and their corresponding primary trisomic. It was concluded that the results are more compatible with dosage effects than with the gene balance theory.

MORPHOLOGICAL AND CYTOLOGICAL IDENTIFICATION OF THE PRIMARY TRISOMICS OF LOTUS PEDUNCULATUS (LEGUMINOSAE)

1968 ◽  
Vol 10 (1) ◽  
pp. 161-179 ◽  
Author(s):  
Chi-Chang Chen ◽  
W. F. Grant
Keyword(s):  
Extra Chromosome ◽  
Diploid Species ◽  
Positive Correlation ◽  
Primary Trisomics ◽  
Qualitative And Quantitative ◽  
Quantitative Characters ◽  
Lagging Chromosome ◽  
Lotus Pedunculatus

Trisomics have been developed in the diploid species Lotus pedunculatus Cav. (2n = 12) by means of a series of hybridizations. From the progeny of crosses of triploids to the diploid and selfing triploids, 126 (62.38%) diploids, 73 (36.14%) simple trisomics, 2 (0.99%) double trisomics and 1 (0.49%) telosomic trisomic were obtained. The simple trisomic plants were classified into five distinct morphological groups named Round, Broad, Pointed, Narrow and Small according to their distinguishing leaflet characters. Each group differed from the others and from the diploid in a number of qualitative and quantitative characters. These differences were considered to be the result of a change in the genic balance of the plants which was brought about by the addition of the extra chromosome to the complement. The extra chromosomes of Round, Broad, Pointed, Narrow and Small were identified as chromosomes 1, 3, 4, 5, and 6, respectively. Although the frequency of cells with one trivalent varied within and between trisomic types, there was a positive correlation between length and trivalent formation. It is considered that longer chromosomes have a greater chance of forming chiasmata with more than one homologue than shorter ones. The frequency of lagging chromosomes at AI and/or TI was not correlated with the frequency of univalents at diakinesis. No particular trend was apparent as to which extra chromosome, when present as a lagging chromosome, tended to divide more frequently than another chromosome of the complement.

Redescription of the karyotype of five species of the family Bufonidae (Amphibia: Anura) from central area of Argentina

Biologia ◽  
2011 ◽  
Vol 66 (3) ◽  
Author(s):  
Mariana Baraquet ◽  
Julián Valetti ◽  
Nancy Salas ◽  
Adolfo Martino
Keyword(s):  
Significant Contribution ◽  
Average Length ◽  
Chromosome Complement ◽  
Central Area ◽  
Chromosome Length ◽  
Chromosome Morphology ◽  
Morphometric Parameters ◽  
Classification Rate ◽  
The Family ◽  
Karyotype Formula

AbstractIn this study karyotypic features of the five species of the family Bufonidae from the central area of Argentina are described. The species are Rhinella achalensis, Rhinella arenarum, Rhinella fernandezae, Rhinella schneideri and Melanophryniscus stelzneri. The metaphases were obtained from intestinal and testis cells, using conventional techniques. Twenty metaphasic figures per individual were analyzed and the total length of each chromosome and the length of the four arms were measured. The obtained measurements were processed using Excel 2000 to obtain the average length of the arms p and q, the arm ratio, the centromeric index, the relative chromosome length and the relative arm length. All species showed karyotype 2n = 22, and karyotype formula of 6: 5. Pairs one to six were large, with a relative chromosome length between 18.64–7.59%; pairs seven to eleven were small, with a relative chromosome length between 7.18–2.42%. In all species the chromosome morphology was metacentric or submetacentric. Karyotype and ideograms were made for all species, based on morphometric parameters of the chromosome complement. Finally, discriminant analysis was used to separate the five species analyzed, with a highly significant classification rate of 80% and P < 0.0001. These results agree, in general, with those presented by other authors, however, in M. stelzneri detailed karyological studied have not been made so far, thus this work represents a significant contribution to the karyotypic decryption features of this species and the Rhinellla species from central area of Argentina.

GENETICS OF A PRIMARY TRISOMIC SERIES IN BARLEY: IDENTIFICATION BY PROTEIN ELECTROPHORESIS

1970 ◽  
Vol 12 (3) ◽  
pp. 490-495 ◽  
Author(s):  
R. G. McDaniel ◽  
R. T. Ramage
Keyword(s):  
Extra Chromosome ◽  
Seed Proteins ◽  
Disc Electrophoresis ◽  
Protein Electrophoresis ◽  
Primary Trisomics

Disc electrophoresis of seed proteins identified the extra chromosome involved in primary trisomics of barley. Each of the seven primary trisomics could be distinguished from diploids and from each other. Electrophoresis provided a precise biochemical criterion for identification of trisomics.

scholarly journals Nucleic acid content and Chromosome morphology in Chrysanthemum

1969 ◽  
Vol 13 (3) ◽  
pp. 241-250 ◽  
Author(s):  
G. J. Dowrick ◽  
A. S. El Bayoumi
Keyword(s):  
Nucleic Acid ◽  
Chromosome Number ◽  
Dna Content ◽  
Chromosome Numbers ◽  
Chromosome Length ◽  
Chromosome Morphology ◽  
Nucleic Acid Content ◽  
Chromosome Size ◽  
Dna Contents ◽  
The Relationship

1. The DNA contents of twenty-eight different species and forms of Chrysanthemum have been measured by photometry. It is shown that there are large differences in DNA content between some species with identical chromosome numbers.2. The DNA contents of natural polyploids are frequently not those expected when comparison is made with diploid forms of the same species. The DNA contents of induced polyploids are those expected.3. Chromosome length and volume are positively correlated with DNA content.4. The relationship between chromosome number, chromosome size, DNA content and gene number is considered, and it is suggested that the differences in DNA content may result from the presence of differing amounts of genetically inactive DNA in the chromosomes.

Giemsa C-banded karyotypes of Hordeum taxa from North America

1986 ◽  
Vol 28 (1) ◽  
pp. 42-62 ◽  
Author(s):  
I. Linde-Laursen ◽  
Roland von Bothmer ◽  
Niels Jacobsen
Keyword(s):  
Diagnostic Marker ◽  
Marker Chromosome ◽  
Chromosome Length ◽  
Chromosome Morphology ◽  
Banding Patterns ◽  
C Banding ◽  
Close Relationship ◽  
Partial Inactivation ◽  
Pattern Polymorphism ◽  
Nucleolus Organizers

Giemsa C-banding patterns of Hordeum pusillum, H. intercedens, H. brachyantherum (2x, 4x, 6x), H. jubatum, H. arizonicum, and H. depressum (2x and 4x) were rather similar, with mostly small to very small bands with no preferential disposition. The use of C-banding patterns did not improve the level of identification of taxa beyond that reached by the use of chromosome morphology. Widespread banding-pattern polymorphism prevented a reliable identification of homologues among populations based on this character alone. Chromosome length did not differentiate taxa. The ratio longest/shortest chromosome was remarkably constant over taxa, only differentiating the race of H. brachyantherum (4x) from Newfoundland, H. arizonicum, and H. depressum (4x). Marker chromosome morphology suggested the presence of one genome common to all taxa. A further but different genome was common to the perennial polyploids, indicating an alloploid origin and a close relationship calling into question the biological relevance of some sectional divisions in Hordeum. A number of intraspecific chromosome polymorphisms were observed rendering the number of marker chromosomes, a poor diagnostic marker. A pair of relatively shorter submetacentrics than previously reported in Hordeum distinguished the genomes of H. arizonicum and H. brachyantherum (4x) from Newfoundland. A partial inactivation of the nucleolus organizers of one parental genome in interspecific hybrids is considered more common than generally appreciated.Key words: C-banding, karyotype, Hordeum.

CHROMOSOME MORPHOLOGY OF POA TRIVIALIS L.

1972 ◽  
Vol 14 (2) ◽  
pp. 287-291 ◽  
Author(s):  
M. K. Ahmed ◽  
G. Jelenkovic ◽  
W. R. Dickson ◽  
C. R. Funk
Keyword(s):  
Chromosome Number ◽  
Chromosome Complement ◽  
Chromosome Length ◽  
Chromosome Morphology ◽  
Length Ratio ◽  
Poa Trivialis

The chromosome complement in six turf-type genotypes of Poa trivialis was studied. The chromosome number was 2n = 2x = 14. On the basis of chromosome length, ratio between arm lengths, centromeric indices, and presence of constrictions all seven pairs were identified and characterized.

Certation between euploid and aneuploid pollen grains from a tertiary trisomic of rye, Secale cereale L.

Genome ◽  
1987 ◽  
Vol 29 (2) ◽  
pp. 353-356 ◽  
Author(s):  
J. Janse
Keyword(s):  
Secale Cereale ◽  
Seed Weight ◽  
Genetic Factors ◽  
Seed Set ◽  
Transmission Rate ◽  
Extra Chromosome ◽  
Pollen Grains ◽  
Decisive Role ◽  
Germination Percentage ◽  
Secale Cereale L

Male transmission of the translocated extra chromosome 5R3R was studied in a tertiary trisomic of rye (Secale cereale L.) using two pollination densities. With abundant pollen, male transmission reached 4%. When a mean of four pollen grains were brought on every stigma (restricted pollination), a transmission rate of 20% was obtained. Seed set, mean seed weight, germination percentage, and the percentage of plants finally surviving were lower in the case of restricted pollination. It was concluded that certation between euploid and aneuploid pollen grains plays a decisive role in male transmission of the translocated chromosome. Although it was previously shown that aneuploid microspores have a delayed development, a large proportion must have reached maturity before anthesis. Therefore, genetic factors determining male transmission rate will primarily be expressed during pollen germination and tube growth rather than before anthesis. Key words: rye, tertiary trisomic, euploid pollen grains, aneuploid pollen grains, certation.

scholarly journals PRIMARY TRISOMICS OF RICE: ORIGIN, MORPHOLOGY, CYTOLOGY AND USE IN LINKAGE MAPPING

Genetics ◽  
1984 ◽  
Vol 107 (1) ◽  
pp. 141-163
Author(s):  
G S Khush ◽  
R J Singh ◽  
S C Sur ◽  
A L Librojo
Keyword(s):  
Linkage Mapping ◽  
Oryza Sativa L ◽  
Extra Chromosome ◽  
Rice Variety ◽  
Marker Genes ◽  
Linkage Groups ◽  
Primary Trisomics ◽  
Genetic Segregation ◽  
First Time ◽  
Distinguishing Features

ABSTRACT Twelve primary trisomics of Oryza sativa L. were isolated from the progenies of spontaneous triploids and were transferred by backcrossing to the genetic background of IR36, a widely grown high yielding rice variety. Eleven trisomics can be identified morphologically from one another and from diploids. However, triplo 11 is difficult to distinguish from diploid sibs.—The extra chromosome of each trisomic was identified cytologically at pachytene stage of meiosis, and the chromosomes were numbered according to their length at this stage. The major distinguishing features of each pachytene chromosome were redescribed.—The female transmission rates varied from 15.5% for triplo 1, the longest chromosome, to 43.9% for triplo 12, the shortest chromosome. Seven of the 12 primary trisomics transmitted the extra chromosome through the male. The low level of chromosomal imbalance tolerated by rice and other evidence are interpreted to indicate that this species is a basic diploid.—Genetic segregation for 22 marker genes in the trisomic progenies was studied. Of a possible 264 combinations, involving 22 genes and 12 trisomics, 120 were examined. Marker genes for each of the 12 chromosomes were identified. The results helped establish associations between linkage groups and cytologically identifiable chromosomes of rice for the first time. Relationships between various systems of numbering chromosomes, trisomics, linkage groups and marker genes are described, and a revised linkage map of rice is presented.

scholarly journals Development and Applications of a Complete Set of Rice Telotrisomics

Genetics ◽  
2001 ◽  
Vol 157 (1) ◽  
pp. 361-368
Author(s):  
Zhukuan Cheng ◽  
Huihuang Yan ◽  
Hengxiu Yu ◽  
Shuchu Tang ◽  
Jiming Jiang ◽  
...  
Keyword(s):  
Indica Rice ◽  
Extra Chromosome ◽  
Rice Variety ◽  
Rice Chromosome ◽  
Rflp Markers ◽  
Bac Clone ◽  
Primary Trisomics ◽  
Chromosome Arm ◽  
Complete Set

Abstract We previously isolated a complete set of primary trisomics along with many other aneuploids from triploid plants derived from an indica rice variety “Zhongxian 3037.” About 30,000 progeny from these trisomic and aneuploid plants were grown each year from 1994 to 1999. The variants that differed morphologically from both the diploids and the original primary trisomics were collected for cytological identification. From these variants, a complete set of telotrisomics covering all 24 rice chromosome arms was obtained. The identities of the extra chromosomes were further confirmed by dosage analysis of the RFLP markers on extra chromosome arms. The telocentric nature of the extra chromosomes in these stocks was verified by fluorescence in situ hybridization (FISH) using a rice centromeric BAC clone as a marker probe. In general, the shorter the extra chromosome arm of a telotrisomic, the stronger the resemblance it bears to the diploid; the longer the extra chromosome arm, the stronger the resemblance to the corresponding primary trisomic. We demonstrated that DNA clones can be rapidly assigned to specific chromosome arms by dosage analysis with the telotrisomics. We also showed that telotrisomics are valuable tools for chromosome microdissection and for developing chromosome-specific DNA markers.

Sign in / Sign up

Export Citation Format

Share Document