scholarly journals Additive and non-additive genetic variance in odontometric traits in crosses of seven inbred lines of house mice

1974 ◽  
Vol 23 (2) ◽  
pp. 207-217 ◽  
Author(s):  
Larry J. Leamy ◽  
R. W. Touchberry
Keyword(s):  
Combining Ability ◽  
Additive Genetic Variance ◽  
Diallel Analysis ◽  
Inbred Lines ◽  
House Mice ◽  
Reciprocal Effects ◽  
X Irradiation ◽  
The Mean ◽  
Positive Heterosis ◽  
Number Of Individuals

A least-squares diallel analysis of the offspring of crosses of seven inbred lines of house mice was performed for the mean widths of the second (M2) and third (M3) mandibular molars. Significant differences among lines, as well as between inbreds and hybrids (positive heterosis) were found for these characters. Estimates of the heritabilities (from general combining ability variances) were high for both teeth as were estimates of maternal effects. Specific combining ability and reciprocal effects were significant only for the M3. Additionally, X-irradiation reduced the mean number of individuals per litter, and thereby indirectly influenced the widths of both molars.

scholarly journals Diallel Analysis of Diplodia Ear Rot Resistance in Maize

Plant Disease ◽  
1998 ◽  
Vol 82 (6) ◽  
pp. 699-703 ◽  
Author(s):  
A. E. Dorrance ◽  
K. H. Hinkelmann ◽  
H. L. Warren
Keyword(s):  
Combining Ability ◽  
Disease Incidence ◽  
Diallel Analysis ◽  
Diallel Cross ◽  
Inbred Lines ◽  
General Combining Ability ◽  
Reciprocal Effects ◽  
Ear Rot ◽  
Stenocarpella Maydis ◽  
High Degree

A diallel cross of seven inbreds and one synthetic line of maize were analyzed in 1994 and 1995 for their reaction to Diplodia ear rot. An additional inbred line was included in the 1995 analysis. Plants were inoculated by placing a pycnidiospore suspension (5 × 103 spores per ml) of Stenocarpella maydis in the whorl at the V14 to V15 growth stage. Crosses were evaluated for disease incidence of Diplodia ear rot at harvest, and the percentage of plants with Diplodia ear rot in a plot was used for analysis. In both years, general combining ability (GCA) effects were significant. In 1995, specific combining ability effects were also significant. There were no reciprocal effects. There was no significant interaction between year and genotypes, indicating that crosses reacted the same in both years. Inbred lines B37, H111, B68, and MS had negative GCA effects that contributed toward resistance in both years. VA26, with intermediate resistance to Diplodia ear rot, contributed toward susceptibility. Only inbred lines with a high degree of resistance should be used as parents.

Combining ability for aluminium tolerance in triticale

1999 ◽  
Vol 133 (4) ◽  
pp. 371-377 ◽  
Author(s):  
X. G. ZHANG ◽  
R. S. JESSOP ◽  
F. ELLISON
Keyword(s):  
Genetic Variation ◽  
Stress Tolerance ◽  
Combining Ability ◽  
Additive Genetic Variance ◽  
Diallel Analysis ◽  
Aluminium Tolerance ◽  
Additive Effects ◽  
Al Tolerance ◽  
Al Stress ◽  
Polygenic System

Root re-growth, following aluminium (Al) stress, has been used as an indicator of Al stress tolerance. Genetic variation in root re-growth characteristics among eight triticale genotypes was investigated by a diallel analysis. Highly significant variation due to both general combining ability (GCA) effects and specific combining ability (SCA) effects indicated that both additive effects and non-additive effects were important in explaining the genetic variation for Al tolerance. The high estimates of heritability and the predictability ratio for root re-growth revealed the preponderance of additive genetic variance in the inheritance of Al tolerance. Differences in patterns of GCA effects and SCA effects among the parents provided strong evidence that the genetic control of variation for Al tolerance as assessed by root re-growth was a complex polygenic system. Three Al-tolerant genotypes, Tahara, Abacus, and 19th ITSN 70–4, were found to be the best general combiners for larger root re-growth, and they could be used in hybridization programmes to improve Al stress tolerance by following a simple pedigree method of selective breeding.

scholarly journals Combining Ability for Grain Yield Performance among CIMMYT Germplasm Adapted to the Mid-Altitude Conditions

2018 ◽  
Vol 10 (3) ◽  
pp. 253
Author(s):  
Casper Nyaradzai Kamutando ◽  
Cosmos Magorokosho ◽  
Shorai Dari
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Additive Genetic Variance ◽  
Inbred Lines ◽  
Nitrogen Stress ◽  
Environment Interaction ◽  
Yield Performance ◽  
Low Nitrogen Stress ◽  
Stress Environments ◽  
Low Nitrogen

The International Centre for Maize and Wheat Improvement (CIMMYT) develops maize (Zea mays L.) inbred lines and hybrids yearly that have several breeding and commercial attributes. However, no genetic analysis has been done on the recently developed inbred lines for yield performance under drought and low-N stress. The objectives of this study were to identify lines with positive general combining ability (GCA) effects for grain yield under stress environments and to identify the best single-cross hybrids with the highest specific combining ability (SCA) effects. Analysis of variance combined across sites showed significant mean squares for genotypes, locations and genotype by environment interaction (GEI) for grain yield. GCAlines, SCA and components of interaction effects were significant across sites. Additive genetic variance was more important than dominance variance in determining yield performance across locations indicating that selection based on grain yield under drought and low-N stress can be effective. Average grain yield across the eight locations ranged from 1.61 t ha-1 to 10.63 t ha-1 while narrow sense heritability for grain yield was 52.6% across sites and was slightly lower under managed drought and low-N stress. The testers CL115807 and CL106622 showed positive and significant GCA effects for yield performance under drought and low-N stress respectively. The best tester across all sites was CL115793 and line CZL0713 had consistently positive GCA effects for grain yield across sites. CML536 × CL115802 and CML312 × CL106508 were the best single crosses under low nitrogen stress sites while hybrid CML312 × C323-45 showed the highest positive SCA effects across sites. In conclusion, our results show that CIMMYT has new lines that have desirable adaptive attributes when grown under drought and low nitrogen stress environments in the mid-altitude region; hence these can be adopted for hybrid, synthetic and OPV formation.

scholarly journals Selection of parents for low nitrogen stress through the combining ability of maize partially inbred lines

2019 ◽  
Vol 41 ◽  
pp. e42705
Author(s):  
Rafael Heinz ◽  
Larissa Pereira Ribeiro ◽  
Manoel Carlos Gonçalves ◽  
Leonardo Lopes Bhering ◽  
Paulo Eduardo Teodoro
Keyword(s):  
Combining Ability ◽  
Diallel Analysis ◽  
Inbred Lines ◽  
General Combining Ability ◽  
Adjusted Means ◽  
Coefficient Of Concordance ◽  
Low Nitrogen Stress ◽  
The Individual ◽  
High Yields ◽  
Low Nitrogen

The objective of this work was to estimate the general combining ability of partially inbred lines under high and low nitrogen (N) conditions and to select promising lines to obtain high yields for both conditions. Fifty-five partially inbred S1 progenies were evaluated using the top-cross method, where the lines were crossed with two testers. The 110 top-cross hybrids were evaluated for grain yield during the off-season of 2012 at two sites in the Brazilian Midwest. Partial diallel analysis was performed with the adjusted means of each of the individual analyses of the top crosses. The combining ability of partially inbred lines and testers as well as their interaction with N levels, was estimated for each site. The coefficient of concordance among 15 partially inbred lines selected by the highest general combining ability estimates for each N level was 0.60. The S1 lines 39, 11, 41, 55, 38, 37, 6, 8, and 14 were selected at both N levels. This indicates that these lines can be used to identify ideal hybrids for growing in the off-season in the Brazilian Midwest.

scholarly journals The effects on litter size of crossing lines of mice inbred without selection

1960 ◽  
Vol 1 (2) ◽  
pp. 239-252 ◽  
Author(s):  
R. C. Roberts
Keyword(s):  
Natural Selection ◽  
Litter Size ◽  
Combining Ability ◽  
Variance Components ◽  
Inbred Lines ◽  
Inbreeding Coefficient ◽  
Basic Information ◽  
Outbred Population ◽  
Combining Abilities ◽  
The Mean

1. The experiment was designed to provide basic information relevant to the utilization of heterosis in animal improvement. The character studied was the size of the first litter in mice.2. Thirty inbred lines were crossed at random when the inbreeding coefficient reached 0·50 (three full-sib matings). The lines had been inbred without selection except for natural selection operating with lines.3. The mean litter size of the crossbred mice did not exceed that of the outbred population from which the inbred lines had been derived. This indicates that the increased litter size normally associated with crossbred mice must be ascribed to some form of selection other than within-line natural selection.4. Estimates were obtained of the variance components associated with general and special combining abilities. As anticipated, these estimates were very small, especially those relating to special combining ability. Before selection between crosses becomes possible, high levels of inbreeding must be achieved.

scholarly journals Investigation of Doubled Haploid Performance and Combining Ability in Short-day Onion

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 990B-990 ◽  
Author(s):  
Ryan L. Walker ◽  
Sunggil Kim ◽  
Javier F. Betran ◽  
Kilsun Yoo ◽  
Leonard M. Pike
Keyword(s):  
Doubled Haploid ◽  
Combining Ability ◽  
Inverse Correlation ◽  
Inbred Lines ◽  
Breeding Program ◽  
Soluble Solids ◽  
Reciprocal Effects ◽  
Breeding Programs ◽  
Solids Content ◽  
Dh Lines

Onions suffer from severe inbreeding depression, which has inhibited the development of homozygous inbred lines in breeding programs. The creation of doubled haploid (DH) lines in onion provides a unique opportunity to evaluate the utility of such lines as parents in a breeding program. For this purpose, two diallele cross experiments were conducted. The first consisted of a six-parent diallele cross using six DH lines developed at Texas A&M University. The second, a four-parent diallele cross performed with two DH lines and two inbred lines from the breeding program. Bulbs from the various crosses were evaluated for diameter, height, centers/bulb, ring thickness, number of rings/bulb, bulb weight, soluble solids content, and pungency. For some traits, general combining ability (GCA) effects explained most of the variation. However, for other traits, specific combining ability (SCA) effects predominated. For all traits, GCA and SCA were always larger than the reciprocal effects (divided into maternal and nonmaternal components). The GCA and SCA effects show an inverse correlation between the number of centers/bulb and ring thickness.

scholarly journals PENDUGAAN PARAMETER GENETIK PADA PERSILANGAN DIALEL BEBERAPA TETUA CABAI (Capsicum annuum L.)

2015 ◽  
Vol 24 (1) ◽  
pp. 1
Author(s):  
Sri Romaito Dalimunthe
Keyword(s):  
Combining Ability ◽  
Block Design ◽  
Diallel Analysis ◽  
Inbred Lines ◽  
Fruit Weight ◽  
High Genetic Diversity ◽  
Diallel Crossing ◽  
Recessive Genes ◽  
High Heritability ◽  
Materials Used

High genetic diversity in chili is the basis for a chili breeding program. One of the methods to increase diversity is through crossing. There are several crossing designs in order to produce new varieties, such as diallel crossing. Diallel analysis is a method for studying the inheritance of characteristics from various crossings. The aim of this research was to estimate the genetic parameters, the general combining ability (GCA) and specific combining ability (SCA) of six inbred lines of chili. The research was conducted in November 2008-May 2009 at the Experimental Farm Leuwikopo IPB. Genetic materials used were six inbred lines of chili (IPB C2, IPB C9, IPB C10, IPB C14, IPB C15 and IPB C20) and the F1s of the combination of six inbred lines. The experimental design was Randomized Complete Block Design with a single factor, namely genotype. The number of genotypes were 36 with three replications, so there were 108 units of experiment. The crossing design used was diallel crossing design. The results showed that there were no interaction between genes on the dichotomous height and fruit weight, significant additive effects, the control genes spread unevenly, and relatively high heritability values. Genotype which carried recessive genes the most was IPB C14 and genotype which carried the most dominant genes was IPB C10. IPB C10 showed the highest GCA for dichotomous height and IPB C2 showed the highest GCA on fruit weight. The crossing between IPB C2 x IPB C10 showed the highest SCA for dichotomous height. For fruit weight, crossing of IPB C2x IPB C14 had the highest SCA. Crossing combination of IPB C2 x IPB C14 was the best hybrid.

GENETIC NATURE OF TWO INDEXES OF COMPATIBILITY IN ALFALFA

1971 ◽  
Vol 13 (1) ◽  
pp. 51-54 ◽  
Author(s):  
S. M. Singh ◽  
K. Lesins
Keyword(s):  
Combining Ability ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Relative Magnitude ◽  
General Combining Ability ◽  
Total Variance ◽  
Reciprocal Effects ◽  
Diallel Crosses ◽  
Yielding Ability ◽  
Number Of Seeds

Seven clones selected for their high seed and forage yielding ability were crossed in a diallel manner to obtain the estimates of GCA, SCA and reciprocal effects of the parental clones in various hybrid combinations. The analysis of the diallel crosses revealed that the variances for GCA, SCA and reciprocal effects were significant (0.01 level) for percentage of pod set during the crossing program. Number of seeds per pod set were significant for the general combining ability. The general combining ability appeared to be of greater importance for both the characters studied, and the additive genetic variance seems to constitute approximately 63% of the total variance for percentage of pod set and 71% of the total variance for number of seeds per pod set. However, wide differences were found among the clones in the relative magnitude of GCA, SCA and reciprocal effects for both traits.

scholarly journals Combining ability of inbred lines of maize and stability of their respective single-crosses

2003 ◽  
Vol 60 (1) ◽  
pp. 83-89 ◽  
Author(s):  
Aurélio Mendes Aguiar ◽  
Luciana Aparecida Carlini-Garcia ◽  
Adelmo Resende da Silva ◽  
Mateus Figueiredo Santos ◽  
Antonio Augusto Franco Garcia ◽  
...  
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Zea Mays L ◽  
Block Design ◽  
Diallel Analysis ◽  
Inbred Lines ◽  
Breeding Programs ◽  
Randomized Complete Block Design ◽  
Single Cross ◽  
Ear Height

The utilization of diallel crosses for identification of superior combinations is a common practice in maize (Zea mays L.) breeding programs. This methodology allows the estimation of the combining ability of genotypes being evaluated. In this work, five inbred lines were evaluated as to their general (GCA) and specific (SCA) combining abilities, by using a complete diallel scheme. The single-crosses produced between these inbred lines were evaluated in seven environments, along with two checks, by using a randomized complete block design. Traits analized were: grain yield, plant height, ear height, ear placement, and prolificacy. A diallel analysis was carried out, following an adaptation of Griffing's method IV, in addition to hybrid stability and adaptability analyses. Significant differences were detected for entries and environments for all traits. The interaction genotype vs. environment was significant for all traits. GCA's were significant for all traits, while SCA's were non-significant only for ear placement. For grain yield, both additive (GCA) and non-additive (SCA) effects were important, while for the remaining traits additive effects were more important. The high yielding single-cross was obtained from the cross of lines L-08-05F and L-38-05D. Those inbred lines showed higher GCA's and their cross also had high SCA; also, it is responsive to environment improvements and reasonably stable. The second in rank high yielding single-cross, L-46-10D x L-08-05F, showed wide adaptability and stability.

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