Genetic control of environmentally induced DNA variation in flax genotrophs

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 643-646 ◽  
Author(s):  
Y. A. Al-Saheal ◽  
A. S. Larik
Keyword(s):  
Key Words ◽  
Genetic Control ◽  
Nuclear Dna ◽  
Nitrogen And Phosphorus ◽  
Cytoplasmic Factor ◽  
Dna Variation ◽  
Homologous Chromosomes ◽  
Reciprocal Crosses ◽  
Cytoplasmic Factors ◽  
Flax Genotrophs

Heritable changes can be induced in the amount of nuclear DNA of the Stormont Cirrus variety (PL) of flax when grown in the specific environments of nitrogen and phosphorus, but such changes did not occur in variety Royal (R). Changes occurred in the amount of nuclear DNA of R when the PL nuclear and cytoplasmic factors were introduced by crossing. In the experiments reported here, tests were made on the plasticity of the F1's of their reciprocal crosses to PL and R to understand why L and S genotrophs are stable. The results suggest that there may be a feedback from nucleus to cytoplasm in L0, which inactivates the cytoplasmic factor. Possibly a paramutation-like mechanism adjusts the different amount of DNA, or heterochromatin, between the homologous chromosomes in heterozygotes. L3 and S3 DNA has reverted to the same amount as in PL. This reversion in DNA appears to be accompanied by an increase in stability rather than in any gain in plasticity. Key words: environment, flax, genotrophs, DNA variation.

Genetic factors determining plasticity in flax genotrophs

1985 ◽  
Vol 27 (3) ◽  
pp. 272-275 ◽  
Author(s):  
Y. A. Al-Saheal ◽  
A. S. Larik
Keyword(s):  
Genetic Analysis ◽  
Genetic Factors ◽  
Nuclear Dna ◽  
Nuclear Factor ◽  
Direct Part ◽  
Cytoplasmic Factor ◽  
Cytoplasmic Factors ◽  
Flax Genotrophs

Changes in the amount of nuclear DNA can be induced in 'Stormont Cirrus', a plastic variety (PL) of flax, by different environments, but not in the linseed variety 'Royal' (R) which is not plastic. PL is thought to contain nuclear and cytoplasmic factors, not possessed by R, which are necessary for the plastic characters to appear. Further crosses have shown that the PL nuclear factor plays a direct part in the determination of plasticity and that the cytoplasmic factor is maintained in the presence of both PL and R nuclei. Insofar as the genetic analysis has been taken, the distribution of genetic factors determining plasticity (+) or nonplasticity (−) in PL and R are as follows: nuclear factor (PL, +; R, −); cytoplasmic factor (PL, +; R, −); nuclear factor for synthesizing de nouveau cytoplasmic factor (PL, −; R, −); nuclear factor for maintaining the cytoplasmic factor (PL, +; R, +); site at which DNA changes occur (PL, +; R, +). It is suggested that the nuclear factor is activated by the cytoplasmic factor, and must come directly from a cytoplasm containing the cytoplasmic factor to be operative.Key words: flax, genotype plasticity, plasticity, genotrophs.

Genetic parameters of flax genotrophs. V. Behaviour of nuclear DNA in parental and F1 generations

1985 ◽  
Vol 27 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Y. A. Al-Saheal ◽  
A. S. Larik
Keyword(s):  
Temperature Effects ◽  
Genetic Parameters ◽  
Nuclear Dna ◽  
Direct Part ◽  
Cytoplasmic Factor ◽  
Dna Values ◽  
Flax Genotrophs ◽  
Flax Variety ◽  
Dna Amounts

The nuclear DNA difference between large (L) and small (S) genotrophs, induced in the flax variety 'Stormont Cirrus' (PL), was investigated using Feulgen photometry. L and S genotrophs were crossed, respectively, to the PL genotype and the parental, and F1 generations were grown in greenhouse (T1) and field (T2) temperatures. Results demonstrate that (i) the DNA values show increased reversion in the crosses, compared with the parents at T1 and less reversion in the crosses, than in the parents, at T2; (ii) more reversion occurs in the PL maternal crosses than in the PL paternal crosses; and (iii) the PL genotroph possess a nuclear and a cytoplasmic factor which plays a direct part in determining nuclear DNA changes in the chromosomes of the stable genotype.Key words: rDNA, DNA amounts, genotrophs, temperature effects.

RELATIONSHIP OF TAXA IN THE GENUS MEDICAGO AS REVEALED BY HYBRIDIZATION. I. M. STRIATA × M. LITTORALIS

1968 ◽  
Vol 10 (2) ◽  
pp. 263-275 ◽  
Author(s):  
K. Lesins ◽  
A. Erac
Keyword(s):  
High Mortality ◽  
Genetic Factor ◽  
Genetic Factors ◽  
Chromosomal Rearrangements ◽  
Cytoplasmic Factor ◽  
Reciprocal Crosses ◽  
Gross Chromosomal Rearrangements ◽  
Coiling Direction ◽  
Chlorophyll Deficiencies ◽  
Relationship Of

In crosses between the two taxa Medicago striata Bast, and M. littoralis Rohde a high mortality of gametes and seedlings, and sterility of some plants were noted which were not related to gross chromosomal rearrangements. Although the F1, F2 and F3 generations from reciprocal crosses differed in chlorophyll deficiencies (indicating a cytoplasmic influence) a genic cause became evident from segregations for chlorophyll characters in the F2 and F3. Transference of the cytoplasmic factor by the pollen is indicative.Segregation for pod coiling direction indicated that the character was determined by one or two genetic factors of which the clockwise coiling direction is recessive. The spininess appeared to be determined by one genetic factor, of which the spineless allele is recessive.On the basis of genetic differences (especially on the built-in repulsion systems for normal chlorophyll development of opposite species) the two taxa should be considered two different species.

Mitochondrial and nuclear DNA variation, genotype fingerprinting and genetic relationships in lentil (Lens culinaris Medik.)

1997 ◽  
Vol 77 (4) ◽  
pp. 515-521 ◽  
Author(s):  
Om P. Rajora ◽  
John D. Mahon
Keyword(s):  
Mitochondrial Dna ◽  
Restriction Fragment ◽  
Lens Culinaris ◽  
Nuclear Dna ◽  
Genetic Relationships ◽  
Restriction Enzymes ◽  
Dna Variation ◽  
Apocytochrome B ◽  
Nuclear Dna Variation ◽  
Mean Similarity

Mitochondrial DNA (mtDNA) and nuclear DNA (nuDNA) variations were examined in six cultivars of Lens culinaris ssp. culinaris and two (mtDNA) or one (nuDNA) accession(s) of L. culinaris ssp. orientalis. Total leaf DNA was digested with up to 15 restriction endonucleases, separated by agarose gel electrophoresis and trasferred to nylon membranes. To examine mtDNA variation, blots were probed with mtDNA coding for cytochrome c oxidase I (coxI) and ATPase 6 (atp6) of both wheat and maize as well as apocytochrome b (cob) and Orf25 (orf25) of wheat. Sixteen combinations of mtDNA probes and restriction enzymes revealed 34 fragments that discriminated between at least two lentil accessions. For nuDNA analysis, probes from cDNA and genomic DNA clones of lentil were used to probe the same blots, and identified 46 diagnostic fragments from 19 probe/enzyme combinations. Each lentil accession could be unequivocably distinguished from all others on the basis of both mitochondrial and nuclear DNA fragment patterns. The mitochondrial restriction fragment similarities ranged from 0.944 to 0.989, with a mean of 0.970 but nuclear restriction fragment similarities varied from 0.582 to 0.987, with a mean of 0.743. The apparent genetic relationships among accessions differed according to the source of DNA examined, although the commercial varieties Laird, Brewer and Redchief showed similarly high levels of mean similarity with both nuclear (0.982) and mitochondrial DNA (0.983). Key words: Lens culinaris Medik., genetic variation, mitochondrial, nuclear, DNA, lentil

scholarly journals Genome size mediates the effect of environmental filtering in determining plant β-diversity across temperate grasslands

2021 ◽  
Author(s):  
Hai-Yang Zhang ◽  
Xiaotao Lü ◽  
cunzheng wei ◽  
Jeff Powell ◽  
Xiaobo Wang ◽  
...  
Keyword(s):  
Genome Size ◽  
Community Assembly ◽  
Nuclear Dna ◽  
Environmental Filtering ◽  
Nuclear Dna Content ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Nitrogen And Phosphorus ◽  
Temperate Grasslands ◽  
Β Diversity

Elucidating mechanisms underlying community assembly and biodiversity patterns is central to ecology and evolution. Genome size (GS, i.e. nuclear DNA content) determines species’ capacity to tolerate environmental stress or to exploit new environments and therefore potentially drive community assembly. However, its role in driving β-diversity (i.e., the site-to-site variability in species composition) remains unclear. We measured GS for 169 plant species and investigated their occurrences within plant communities across 52 sites spanning a 3200-km transect in the temperate grasslands of China. We found environmental factors showed larger effects on β-diversity of large-GS than that of small-GS species. Community weighted mean GS increased with mean annual precipitation, soil total nitrogen and phosphorus concentrations, but decreased with mean annual temperature, suggesting a negative selection against species with large GS in resources-limited or warmer climates. These findings highlight the roles for GS in driving community assembly and predicting species responses to climate change.

scholarly journals Mitochondrial DNA Variation Dictates Expressivity and Progression of Nuclear DNA Mutations Causing Cardiomyopathy

2019 ◽  
Vol 29 (1) ◽  
pp. 78-90.e5 ◽  
Author(s):  
Meagan J. McManus ◽  
Martin Picard ◽  
Hsiao-Wen Chen ◽  
Hans J. De Haas ◽  
Prasanth Potluri ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Nuclear Dna ◽  
Dna Variation ◽  
Dna Mutations

Factors influencing transmission of alfalfa mosaic virus through seed of annual medics (Medicago spp.) and the genetic control of seed transmission rate

1997 ◽  
Vol 48 (7) ◽  
pp. 989 ◽  
Author(s):  
W. Pathipanawat ◽  
R. A. C. Jones ◽  
K. Sivasithamparam
Keyword(s):  
Mosaic Virus ◽  
Genetic Control ◽  
Transmission Rate ◽  
Alfalfa Mosaic Virus ◽  
Seed Transmission ◽  
Virus Concentration ◽  
Rate Condition ◽  
Reciprocal Crosses ◽  
Transmission Rates ◽  
Annual Medics

Factors likely to influence rates of transmission of alfalfa mosaic virus (AMV) through seed to seedlings of annual medics (Medicago spp.) and genetic control of the magnitude of its seed transmission rate were investigated in plants from 17 early-flowering accessions of M. polymorpha and in progenies of crosses involving M. murex cv. Zodiac × accession 5320 as parents. Plants were graft-inoculated when 6 weeks old to ensure successful and uniform infection. To exclude variation in seed transmission rates due to virus isolate or temperature, only 1 AMV isolate was used and the plants were kept under uniform temperature conditions. In M. polymorpha, significant differences were found between accessions in the levels of AMV transmitted through seed to progeny seedlings, SA 8250 giving the highest mean level of seed transmission (52%) and SA 4188 the lowest (3%). Neither virus concentration nor symptom severity influenced the rates of seed transmission obtained. However, part of the variation in seed transmission rates found in these accessions was related to their flowering times, seed transmission rates increasing as the interval between inoculation and owering increased. In seed samples collected from individual graft-inoculated plants of M. murex from (i) the F2 generation from crosses and reciprocal crosses, and (ii) the backcross progenies, the rates of transmission of AMV through seed to seedlings ranged from 0 to 77% and showed a continuous pattern of variation. Also, there was evidence of transgressive segregation for the low seed transmission rate condition. This indicates that the low seed transmission rate condition for AMV in medics is quantitatively inherited and under polygenic control. In contrast, when the pods from F2 progeny plants from the crosses and reciprocal crosses were examined, the segregation ratios obtained revealed that the smooth pod character from parent accession 5320 was controlled by a single recessive gene, for which the name sp is proposed. The presence in a plant of gene sp, or of its spiny pod-determining allele from the other parent cv. Zodiac, was not correlated with low seed transmission rates of AMV. It is concluded that selection for low rates of seed transmission and a population breeding approach can be used to produce improved M. polymorpha and M. murex cultivars with good resistance to seed-borne AMV

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