scholarly journals Inheritance of Resistance to Chlorpyrifos in the Mt Alford Strain and to Diazinon in the Gracemere Strain of the Cattle Tick (Boophilus micro plus)

1982 ◽  
Vol 35 (4) ◽  
pp. 427 ◽  
Author(s):  
BF Stone ◽  
NJ Youlton
Keyword(s):  
Average Degree ◽  
F1 Hybrids ◽  
Cattle Tick ◽  
Inheritance Of Resistance ◽  
Incomplete Dominance ◽  
Resistance Factors ◽  
Degree Of Dominance ◽  
Phenotype Analysis ◽  
Reciprocal Crossing ◽  
D Values

Reciprocal crossing of the Mt Alford (A) strain of the cattle tick B .. micro pius with a susceptible (8) strain and phenotype analysis of F 1, testcross and F 2 progeny showed that high chlorpyrifos resistance in strain A was due to two genes that were complementary and jointly exhibited incomplete dominance. Diazinon resistance in the Gracemere (G) strain appeared to be similarly inherited. The 'average' degree of dominance ('average dominance', D ?? ) of high chlorpyrifos resistance over susceptibility, exhibited by F 1 hybrids from A x 8 reciprocal crossings, was + 0�54 on a -1 to + 1 scale and was not significantly different from the parametric value of + O' 5 (semi-dominance). The corresponding D ?? values revealed by G x 8 crossings were + 0�42 for diazinon resistance (significantly less than +0'5) and -0,031 for chlorpyrifos resistance (not significantly different from zero and therefore exhibiting zero dominance/recessivity). Resistance factors for chlorpyrifos in strains A and G forhomozygotes were 74 and 35, respectively, and for F1 hybrids were 25-29 and 5-7, respectively. The resistance factors for diazinon in strain G for homozygotes and F1 hybrids were 174 and 37-41, respectively.

scholarly journals Inheritance of Dimethoate Resistance in the Mackay Strain of the Cattle Tick (Boophilus Microplus) in Australia

1973 ◽  
Vol 26 (2) ◽  
pp. 445 ◽  
Author(s):  
BF Stone ◽  
JT Wilson ◽  
Nerida J Youlton
Keyword(s):  
Boophilus Microplus ◽  
Susceptible Strain ◽  
Autosomal Gene ◽  
Cattle Tick ◽  
Test Cross ◽  
Phenotype Analysis ◽  
Reciprocal Crossing ◽  
F2 Progeny

Reciprocal crossing with a susceptible strain and phenotype analysis of F l , test cross, and F2 progeny for resistance showed that dimethoate resistance in the Mackay strain of the cattle tick Boophilus micro plus was due to an incompletely dominant autosomal gene.

Inheritance of Resistance to The Auxinic Herbicide Dicamba in Kochia (Kochia scoparia)

Weed Science ◽  
2009 ◽  
Vol 57 (1) ◽  
pp. 43-47 ◽  
Author(s):  
Christopher Preston ◽  
David S. Belles ◽  
Philip H. Westra ◽  
Scott J. Nissen ◽  
Sarah M. Ward
Keyword(s):  
Dry Weight ◽  
Inheritance Of Resistance ◽  
Kochia Scoparia ◽  
Susceptible Line ◽  
Degree Of Dominance ◽  
Hand Pollination ◽  
Single Allele ◽  
Seven Generations ◽  
High Degree ◽  
Family Segregation

The inheritance of resistance to the auxinic herbicide dicamba was examined in a kochia population from Nebraska. An inbred, resistant line was developed by selection and selfing over seven generations to ensure any resistance alleles would be homozygous in the parents. An inbred, susceptible line was similarly developed, but without selection. Dose–response experiments with dicamba determined a glyphosate-resistant concentration required to inhibit dry weight accumulation by 50% (GR50) of 45 and 1,331 g ae ha−1for the susceptible and resistant populations, respectively. F1crosses were made between resistant and susceptible inbred individuals by hand-pollination, and the F1plants were selfed to produce F2plants. The F2population was screened with 280 g ha−1dicamba, a rate that could discriminate between susceptible and resistant plants. A total of eight F2families were screened twice. In the first screen, seven F2families segregated in a 3:1 ratio, consistent with a single dominant allele controlling resistance, and in the second screen six F2families segregated in a 3:1 ratio. F2individuals were selfed, the F3progeny were tested with 280 g ha−1dicamba, and the genotype of each F2parent was determined based on F3progeny segregation. F3family segregation was consistent with the F2parents having a 1:2:1 homozygous-susceptible:heterozygote:homozygous-resistant pattern, confirming that resistance to dicamba in kochia is likely conferred by a single allele with a high degree of dominance.

scholarly journals THE GENETIC VARIABILITY OF THIRD CHROMOSOMES IN A LOCAL POPULATION OF DROSOPHILA MELANOGASTER

Genetics ◽  
1976 ◽  
Vol 82 (1) ◽  
pp. 63-82
Author(s):  
Takao K Watanabe ◽  
Osamu Yamaguchi ◽  
Terumi Mukai
Keyword(s):  
Drosophila Melanogaster ◽  
Balancing Selection ◽  
Local Population ◽  
Load Ratio ◽  
Average Degree ◽  
Large Cage ◽  
Degree Of Dominance ◽  
Cage Population ◽  
The Difference ◽  
Lethal Genes

ABSTRACT Five hundred and two third chromosomes were extracted from a large cage population of Drosophila melanogaster initiated two months after collection of the progenitors near Raleigh, North Carolina in 1970.—Salivary gland chromosomes of 489 chromosome lines were examined and 54 chromosomes were found to carry inversions. The inversions were classified into three polymorphic types [In(3L)P, In(3R)P, and In(3R)C] and two unique types. The polymorphic inversions were found in frequencies of 0.012, 0.088, and 0.010, respectively.—Viabilities of homozygotes and heterozygotes were examined. Chromosomes with lethals occurred with a frequency of 0.495: 0.537 in the group of inversion-carrying chromosomes and 0.490 in the group of inversion-free chromosomes. The average homozygote viability computed on the basis of an average heterozygote viability of 1.0000 was 0.3235 if lethal lines were included and 0.6290 if they were excluded. The detrimental load to lethal load ratio (D:L ratio) was 0.70 (=0.4636-0.6650). The average viability of lethal heterozygotes was significantly larger than that of lethal-free heterozygotes. It appears, however, that lethal genes in heterozygotes have deleterious effects on fitness as a whole.—The average degree of dominance for viability polygenes was estimated to be about 0.3-0.4 in lethal-free individuals and nearly zero in lethal heterozygotes. Overdominance or some form of balancing selection was suggested at some loci. The difference between the values obtained for average degree of dominance due to genetic backgrounds and superior vibaility of lethal heterozygotes (but not fitness as a whole) suggests that some epistasis or coadaptation occurs.—The results described above are similar to those obtained for the second chromosomes (Mukai and Yamaguchi 1974).

scholarly journals Heterosis, Combining Ability, Genetic Diversity and their Interrelationship in Pigeonpea [Cajanus cajan (L.) Millspaugh]

2021 ◽  
Author(s):  
D. Chandra ◽  
S.K. Verma ◽  
A.K. Gaur ◽  
C. Bisht ◽  
A. Gautam ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Combining Ability ◽  
High Frequency ◽  
Block Design ◽  
General Combining Ability ◽  
F1 Hybrids ◽  
Randomized Block Design ◽  
Degree Of Dominance ◽  
Correlation Result ◽  
Per Se

Background: The development of superior hybrids is must to break the existing yield plateau ( less than 800 kg/ha) in pigeonpea and hence, the genetic mechanism governing the heterosis in pigeonpea must be decoded. Methods: The present study was laid down using randomized block design during kharif 2018-19 at GBPUAT, Pantnagar with 36 genotypes (8 parents and 28 F1 hybrids) of pigeonpea. The estimates of combining ability were evaluated by using the Griffing’s, Method II, Model I. The observations recorded for yield and related traits were subjected to the estimation of genetic diversity (GD) using the D2 statistics. The correlation between heterosis and different parameters viz., parental mean (PM), specific combining ability (SCA), mean of general combining ability (MGCA) and genetic diversity (GD) were estimated by using Pearson’s correlation. Result: High estimates of SCA variance and more than unity ( greater than 1) average degree of dominance for all the characters indicated the presence of over dominance. The SCA followed by MGCA were found to be most reliable parameters to predict the heterosis. The parents having high x low or high x high per se performance, good x poor GCA effects and with medium genetic diversity resulted in high frequency of heterotic hybrids.

scholarly journals Использование мутантных генов томата при селекции на гетерозис

2021 ◽  
Author(s):  
Милания Маковей ◽  
Keyword(s):  
Growing Season ◽  
F1 Hybrids ◽  
Marker Genes ◽  
High Effect ◽  
Degree Of Dominance

The article presents the results on the use of lines of carriers of mutant marker genes in crossings to obtain heterotic F1 hybrids. The degree of dominance of the main traits of determining productivity (the duration of the growing season, the average number of flowers on inflorescences, the number of fruits and the mass of the fruit), depending on the characteristics of the initial parental forms, is shown. Combina-tions of hybrids with a high effect of heterosis in all studied features are isolated.

scholarly journals REGIONS OF STABLE EQUILIBRIA FOR MODELS OF DIFFERENTIAL SELECTION IN THE TWO SEXES UNDER RANDOM MATING

Genetics ◽  
1977 ◽  
Vol 85 (1) ◽  
pp. 171-183
Author(s):  
J F Kidwell ◽  
M T Clegg ◽  
F M Stewart ◽  
T Prout
Keyword(s):  
Random Mating ◽  
Equilibrium Structure ◽  
Directional Selection ◽  
Average Degree ◽  
Weak Selection ◽  
Differential Selection ◽  
Degree Of Dominance ◽  
Stable Equilibria ◽  
Selection Intensities ◽  
The Stability

ABSTRACT The equilibrium structure of models of differential selection in the sexes is investigated. It is shown that opposing additive selection leads to stable polymorphic equilibria for only a restricted set of selection intensities, and that for weak selection the selection intensities must be of approximately the same magnitude in the sexes. General models of opposing directional selection, with arbitrary dominance, are investigated by considering simultaneously the stability properties of the trivial equilibria and the curve along which multiple roots appear. Numerical calculations lead us to infer that the average degree of dominance determines the equilibrium characteristics of models of opposing selection. It appears that if the favored alleles are, on the average, recessive, there may be multiple polymorphic equilibria, whereas only a single polymorphic equilibrium can occur when the favored alleles are, on the average, dominant. The principle that the average degree of dominance controls equilibrium behavior is then extended to models allowing directional selection in one sex with overdominance in the other sex, by showing that polymorphism is maintained if and only if the average fitness in heterozygotes exceeds one.

DNA repair defects associated with chromosomal translocation breaksite regions

1994 ◽  
Vol 14 (2) ◽  
pp. 1204-1212
Author(s):  
E J Beecham ◽  
G M Jones ◽  
C Link ◽  
K Huppi ◽  
M Potter ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Strain Analysis ◽  
Chromosomal Translocation ◽  
F1 Hybrids ◽  
Pyrimidine Dimers ◽  
Repair Efficiency ◽  
Gene Level ◽  
Phenotype Analysis ◽  
Allele Specific ◽  
Alpha Gene

Using an assay that measures the removal of UV-induced pyrimidine dimers in specific DNA sequences, we have found that the Pvt-1, immunoglobulin H-C alpha (IgH-C alpha), and IgL-kappa loci are poorly repaired in normal B lymphoblasts from plasmacytoma-susceptible BALB/cAnPt mice. Breaksites in these genes are associated with the chromosomal translocations that are found in > 95% of BALB/cAnPt plasmacytomas. In contrast to those from BALB/cAnPt mice, B lymphoblasts from plasmacytoma-resistant DBA/2N mice rapidly repair Pvt-1, IgH-C alpha, and IgL-kappa. Further, (BALB/cAnPt x DBA/2N)F1 hybrids, which are resistant to plasmacytoma development, carry an efficient (DBA/2N-like) repair phenotype. Analysis of allele-specific repair in the IgH-C alpha locus indicates that efficient repair is controlled by dominant, trans-acting factors. In the F1 heterozygotes, these factors promote efficient repair of BALB/cAnPt IgH-C alpha gene sequences. The same sequences are poorly repaired in the BALB/cAnPt parental strain. Analysis of the strand specificity of repair indicates that both strand-selective and nonselective forms of repair determine repair efficiency at the gene level in nonimmortalized murine B lymphoblasts.

Sign in / Sign up

Export Citation Format

Share Document