Linkage analysis of open bud (ob2) and yellow petal (Y1) in cotton

Genome ◽  
1991 ◽  
Vol 34 (3) ◽  
pp. 461-463 ◽  
Author(s):  
J. E. Endrizzi ◽  
D. T. Ray

In allotetraploid Gossypium species yellow petal is controlled by duplicate dominant genes Y1 (Ah genome) and Y2 (Dh genome), and open bud is controlled by duplicate recessive genes designated ob1 (Dh genome) and ob2 (Ah genome). Y2 and ob1 have been shown previously to be linked on chromosome 18 and 11.5 map units (MU) apart. In this study ob2 and Y1 were transferred from Gossypium darwinii (Watt) accession CB3099 into Gossypium hirsutum L. and found to have a mean recombination percentage of 3.14 for backcross and 3.40 for self-pollinated families from 2n parental heterozygotes and 10.73 in families from mono-18 parental heterozygotes. The lower recombination frequency in the homoeologous linkage group was perhaps due to this chromosome segment being transferred from G. darwinii. The higher frequency of recombination in the monosomic progeny families suggests that the absence of recombination in one homoeologue (chromosome 18) is compensated for by an increase in recombination in the other homoeologue.Key words: cotton, G. hirsutum L., homoeologous linkage groups, genetic markers.

Genetics ◽  
1978 ◽  
Vol 88 (1) ◽  
pp. 49-65
Author(s):  
Robert K Herman

ABSTRACT Two dominant suppressors of crossing over have been identified following X-ray treatment of the small nematode C. elegans. They suppress crossing over in linkage group II (LGII) about 100-fold and 50-fold and are both tightly linked to LGII markers. One, called C1, segregates independently of all other linkage groups and is homozygous fertile. The other is a translocation involving LGII and X. The translocation also suppresses rrossing over along the right half of X and is homozygous lethal. CI has been used as a balancer of LGII recessive lethal and sterile mutations induced by EMS. The frequencies of occurrence of lethals and steriles were approximately equal. Fourteen mutations were assigned to complementation groups and mapped. They tended to map in the same region where LGII visibles are clustered.


Genome ◽  
1995 ◽  
Vol 38 (5) ◽  
pp. 833-837 ◽  
Author(s):  
R. H. Gooding ◽  
B. M. Rolseth

The loci for three enzymes (hexokinase, phosphoglucomutase, and testicular esterase) and two eye-color mutants (brick and tan) are mapped on the X chromosome of Glossina palpalis palpalis. The loci occur in the order brick Hex (tan/Pgm) Est-t, with a recombination frequency of approximately 78% between the outer two loci. The locus for octanol dehydrogenase is located in linkage group II and the loci for malate dehydrogenase and phosphoglucose isomerase are separated by a recombination frequency of about 42.5% in linkage group III. Intrachromosomal recombination occurs at a much lower frequency in males than in females. The distribution of five biochemical marker genes in the linkage groups of G. p. palpalis is markedly different from that found in other higher flies.Key words: tsetse, Glossina palpalis palpalis, linkage map.


1983 ◽  
Vol 42 (3) ◽  
pp. 297-310 ◽  
Author(s):  
D. J. Bond ◽  
S. J. Broxholme

SUMMARYTwo spontaneously arising chromosome rearrangements were isolated in Sordaria brevicollis from one perithecium. These were detected through increased production of black spores in intercrosses of complementing buff spore colour mutants. One was a reciprocal translocation between linkage groups I and II; the other a reciprocal translocation between linkage groups II and VI. In the former case the translocation resulted in frequent non-disjunction generating black spores which were either tertiary or interchange disomics. The frequency of premature centromere division was also increased. In the case of the translocation involving linkage groups II and VI the black spores were formed as a result of adjacent-1 segregation and were probably duplication/deficiency products.In both rearrangements the breakpoint in linkage group II was, as far as could be judged, in an identical place. This and the fact that they were isolated from a single fruiting body, suggests that the chromosome breakage event arose as a potential lesion, which replicated before the potential break was either restituted, to restore a normal chromosome, or opened, to form the rearrangements.


1969 ◽  
Vol 11 (1) ◽  
pp. 184-191
Author(s):  
O. I. Joarder ◽  
A. M. Eunus ◽  
M. A. Rahman

Inheritance of earliness and plant height was studied in a six-parent diallel cross of jute, Corchorus olitorius L. The variety O-6E exhibited an excess of dominant genes, whereas the varieties R-26 and Chinese olitorius showed an excess of recessive genes for the character of earliness. On the other hand the variety Desimasua exhibited an excess of recessive genes and the varieties wild jute and O-5 showed a small excess of dominant genes for the character of plant height. On an overall basis, earliness and plant height were found to be controlled by both dominant and recessive genes, the contribution of the former being greater in earliness, and that of the latter being greater in plant height. Eleven dominant factors were detected to condition plant height, whereas only one dominant factor was involved in controlling earliness. Transgressive segregation for earliness was indicated in arrays with R-26 and Chinese olitorius as recurrent parents. Heritability was calculated to be 61% and 29% respectively for earliness and plant height.


1975 ◽  
Vol 25 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Sheela Srivastava ◽  
Umakant Sinha

SUMMARYTwelve FPA-resistant mutants were selected on medium containingp-fluorophenylalanine and ethionine. Dominance tests in heterozygous diploids showed that 8 out of 12 are dominant and 4 recessive to their wild-type alleles. One mutant,fpa60, showed a partial requirement for tyrosine and was found to be allelic to anfpaAmutant described previously. A tyrosine non-requirer,fpa65, was also assigned to this locus. The other 10 mutants did not show any growth requirement and were simultaneously resistant to ethionine and 3-amino-L-tyrosine. Of the 8 dominant mutants, 3 were allelic to the permease-mutants at the locusfpaD.Dominant mutants showed higher degrees of resistance than recessive ones. Six new loci, identified after preliminary genetic analysis, were located on 3 linkage groups: 3 on linkage group VI, and one each on linkage groups I, V, and VIII. The recombinantfpaD11;fpaK69 was found to be sensitive to FPA.


Genetics ◽  
1988 ◽  
Vol 120 (4) ◽  
pp. 977-986
Author(s):  
K J Kemphues ◽  
M Kusch ◽  
N Wolf

Abstract We have analyzed a set of linkage group (LG) II maternal-effect lethal mutations in Caenorhabditis elegans isolated by a new screening procedure. Screens of 12,455 F1 progeny from mutagenized adults resulted in the recovery of 54 maternal-effect lethal mutations identifying 29 genes. Of the 54 mutations, 39 are strict maternal-effect mutations defining 17 genes. These 17 genes fall into two classes distinguished by frequency of mutation to strict maternal-effect lethality. The smaller class, comprised of four genes, mutated to strict maternal-effect lethality at a frequency close to 5 X 10(-4), a rate typical of essential genes in C. elegans. Two of these genes are expressed during oogenesis and required exclusively for embryogenesis (pure maternal genes), one appears to be required specifically for meiosis, and the fourth has a more complex pattern of expression. The other 13 genes were represented by only one or two strict maternal alleles each. Two of these are identical genes previously identified by nonmaternal embryonic lethal mutations. We interpret our results to mean that although many C. elegans genes can mutate to strict maternal-effect lethality, most genes mutate to that phenotype rarely. Pure maternal genes, however, are among a smaller class of genes that mutate to maternal-effect lethality at typical rates. If our interpretation is correct, we are near saturation for pure maternal genes in the region of LG II balanced by mnC1. We conclude that the number of pure maternal genes in C. elegans is small, being probably not much higher than 12.


Genetics ◽  
1993 ◽  
Vol 133 (4) ◽  
pp. 865-874
Author(s):  
J A Holmes ◽  
D E Johnson ◽  
S K Dutcher

Abstract Linkage group XIX (or the UNI linkage group) of Chlamydomonas reinhardtii has been reported to show a circular meiotic recombination map. A circular map predicts the existence of strong chiasma and chromatid interference, which would lead to an excess number of two-strand double crossovers during meiosis. We have tested this prediction in multipoint crosses. Our results are consistent with a linear linkage group that shows positive chiasma interference and no chromatid interference. Chiasma interference occurs both within arms and across the centromere. Of the original loci that contributed to the circular map, we find that two map to other linkage groups and a third cannot be retested because the mutant strain that defined it has been lost. A second reported unusual property for linkage group XIX was the increase in meiotic recombination with increases in temperature during a period that precedes the onset of meiosis. Although we observed changes in recombination frequencies in some intervals on linkage group XIX in crosses to CC-1952, and in strains heterozygous for the mutation ger1 at 16 degrees, we also show that our strains do not exhibit the previously observed patterns of temperature-sensitive recombination for two different pairs of loci on linkage group XIX. We conclude that linkage group XIX has a linear genetic map that is not significantly different from other Chlamydomonas linkage groups.


Genome ◽  
1997 ◽  
Vol 40 (4) ◽  
pp. 544-551 ◽  
Author(s):  
Yonghe Bai ◽  
T. E. Michaels ◽  
K. P. Pauls

Seven hundred and fifty-six random primers were screened with bulks of genomic DNA from common bacterial blight (CBB) resistant and susceptible bean plants. The plants were from a breeding population derived from an interspecific cross between Phaseolus acutifolius and Phaseolus vulgaris. Four RAPD markers, named R7313, RE416, RE49, and R4865, were found to be significantly associated with CBB resistance in this population. Forty-nine molecular markers segregating in the population were clustered into 8 linkage groups by a MAPMAKER linkage analysis. The largest linkage group was 140 cM long and contained 25 marker loci, including marker R4865. Markers R7313, RE416, and RE49 were clustered on another linkage group. A regression analysis indicated that the markers in these two groups together accounted for 81% of the variation in CBB resistance in the population. The addition of another marker, M56810, which was not individually associated with CBB resistance, increased the total contribution to the trait to 87%.Key words: Phaseolus vulgaris L., common bacterial blight (CBB), polymerase chain reaction (PCR), RAPD markers, linkage groups.


1984 ◽  
Vol 26 (6) ◽  
pp. 762-764 ◽  
Author(s):  
Peter S. Dawson

Reindeer (Rd) is a dominant mutation affecting antenna morphology in the tenebrionid flour beetle, Tribolium castaneum. In contrast with most dominant mutants previously described for this species, homozygotes are fully viable, thus making Rd very useful for genetic studies. Rd is tentatively assigned to either linkage group IX or X. Abbreviated appendages (aa), formerly placed in linkage group X, is reassigned to linkage group V on the basis of demonstrated linkage to jet (j).Key words: Tribolium, mutation Rd, linkage, antenna morphology.


Helia ◽  
2000 ◽  
Vol 23 (33) ◽  
pp. 65-76
Author(s):  
V.V. Kirichenko ◽  
V.N. Popov

SUMMARY The genetics of anodal esterase (Est), cathodal esterase (cEst), cathodal acid phosphatase (cAcp) and malate dehydrogenase (Mdh) has been studied in mature seeds and leaves (genetics of cAcp and Mdh has not been studied in leaves) of sunflower (Helianthus annuus L.). A total of ten loci (four loci of anodal esterase, two loci of cathodal esterase, three loci of malate dehydrogenase and one locus of cathodal acid phosphatase) have been identified and described. Five esterase loci (Est1, Est2, Est3, Est4, cEst5), three malate dehydrogenase loci and one locus of cathodal acid phosphatase are expressed in seeds. Three esterase loci (Est2, cEst5 and cEst6) are expressed in leaves. The analysis of linkage between these loci has been made. Two linkage groups have been found. The sequence of the loci in the first linkage group was Mdh2-Est1- Est2-Est3-cEst5. In the second linkage group it was Est4-cAcp1. Linkages have been analyzed between three isoenzymatic loci expressed in leaves and between two loci controlling morphological traits (branched stem and male fertility restoration). The linkage between morphological traits and isoenzymatic loci has not been revealed. It has been revealed in Br-Rf pair.


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