Showing papers on "Diallel cross published in 1985"
TL;DR: A 6 × 6 diallel cross was conducted in spring-planted oilseed rape (Brassica napus L.) in 1983 at Elora and Dundalk, Ontario, and specific combining ability was as important as general combining ability for 1000 seed weight, physiological maturity, plant height, and lodging resistance.
Abstract: A 6 × 6 diallel cross was conducted in spring-planted oilseed rape (Brassica napus L.) in 1983 at Elora and Dundalk, Ontario. The F1 hybrids exhibited positive heterosis for seed yield, of up to 72...
112 citations
TL;DR: Genetic divergence between the parents had a positive relationship with heterosis and SCA effects of the hybrids of the parents belonging to different groups but not in the same group.
Abstract: Genetic diversity among ten varieties of spring wheat used as parents in a diallel cross was assessed through multivariate analysis (D(2)-statistics) and then related to heterosis and SCA effects of their hybrids. The parents fell into three groups. Group I contained the varieties, 'Nobre', 'Girua' and 'Carazinho'; group II contained 'Sonalika', 'Lyallpur' and 'Pitic 62' and group III contained 'Indus 66', 'Balaka', 'Sonora 64rs and 'MSl'. The varieties of group I were good general combiners, while the varieties of group III were poor combiners. Significant heterotic and SCA effects for yield and yield components were observed in the hybrids of the parents belonging to different groups but not in the same group. Genetic divergence between the parents had a positive relationship with heterosis and SCA effects of the hybrids.
84 citations
TL;DR: In the estimation of genetic variance components for an ancestral reference population in equilibrium, analysis should be applied to F1 data only, and proceed as for a random effects model.
Abstract: Some issues which evidently remain as areas of contention in diallel analysis are reviewed. In the estimation of genetic variance components for an ancestral reference population in equilibrium, analysis should be applied to F1 data only, and proceed as for a random effects model. No meaningful reference population is constituted by the parental sample itself, but an equilibrium reference population which could be derived from these parents can be defined. To give unbiassed estimates of parameters for this population, analysis must include S1 data, and the parents must be homozygous and in linkage equilibrium. Estimation of dominance variance must allow for the fact that the diallel population itself is not in linkage equilibrium by correcting the specific combining ability sum of squares for the mean S1 vs. F1 difference. Some different analyses of variance of the diallel table are discussed in the context of the above reference populations.
49 citations
34 citations
28 citations
TL;DR: Analysis of a six parent diallel cross involving high and low nitrogen fixing peanut (Arachis hypogaea L.) genotypes revealed the predominant nature of non-additive genetic variance for nitrogenase activity and other traits, suggesting the possibility of breeding for increased nitrogen fixation and thus yield in peanut.
Abstract: Analysis of a six parent diallel cross involving high and low nitrogen fixing peanut (Arachis hypogaea L.) genotypes revealed the predominant nature of non-additive genetic variance for nitrogenase activity and other traits. Germplasm line, NC Ac 2821 had the highest general combining ability for nitrogenase activity, total nitrogen, leaf area, and top weight, and therefore, it should be a good parent for use in breeding programs. Nitrogenase activity was significantly and positively correlated with nodule number, nodule mass, total nitrogen, top weight, and root weight. This evidence suggests the possibility of breeding for increased nitrogen fixation and thus yield in peanut.
23 citations
TL;DR: This test provides a simple and rapid technique for net blotch assessment and showed that average effects of alleles were of much greater importance than dominance in controlling resistance.
Abstract: A half diallel was made amongst 5 barley (Hordeum vulgare L.) genotypes (Zephyr, Hassan, Mata, Kaniere, and Manchuria) which varied in resistance to net blotch disease, caused by the fungus Drechslera teres (Sacc.) Shoem. The 5 parents and 10 F1 progeny were grown to physiological maturity in a controlled environment. All genotypes were inoculated first at 14 days after sowing and thereafter 10 times at about weekly intervals. The procedures of Mather and Jinks were used to analyse the half diallel 89 days after sowing. Net blotch infection was measured on top canopy, bottom canopy, flag leaf (leaf number = 1) and second leaf. Infection of detached leaf segments in petri dishes was also analysed. This test provides a simple and rapid technique for net blotch assessment. All analyses showed that average effects of alleles were of much greater importance than dominance in controlling resistance. Epistasis and/or correlated gene distributions were trivial. Resistance was conditioned by a partially d...
21 citations
TL;DR: Protein content and oil content were primarily under the control of non-additive and additive genetic effects, while for number of seeds per boll the variability was accounted for by dominance (H1) effects only.
Abstract: A set of diallel crosses involving ten parents was evaluated over two locations to determine the genetic control of protein per cent, oil per cent, seed index, percentage of mature seeds and number of seeds per boll. The analysis of pooled data showed that percentage of mature seeds was controlled by additive (D) and non-additive (H1 and H2) genetic effects. Overdominance was noticed. For seed index the D component measuring additive, and the H2 component measuring dominance, variation were significant. Protein content and oil content were primarily under the control of non-additive (H1 and H2) genetic effects, while for number of seeds per boll the variability was accounted for by dominance (H1) effects only. The development of pure lines through appropriate methods is suggested.
19 citations
TL;DR: Genetic analysis of the C1DH population showed high additive genetic variance for yield per hill, plant height, and yield per spike, and a high proportion of additive × additive epistasis for spikes perHill, days to heading, and 100-seed weight.
Abstract: Cycle zero (C0) of recurrent selection in barley (Hordeum vulgare L.) was initiated by diallel mating of seven highly selected parents. A total of 398 doubled-haploid (C0DH) lines were derived from 21 crosses and were evaluated along with their parents in C0 experiment. Seven doubled-haploid lines (DH) were selected from the cycle zero (C0) experiment and intercrossed to form cycle 1 (C1). From the 21 crosses of the diallel, 260 doubled-haploid lines (C1DH) were derived and were evaluated along with the C0 and C1 parents. The frequency distribution of the standardized means of the DH lines from C0 and C1 indicated a slight response to selection for seed yield. Genetic analysis of the C1DH population showed high additive genetic variance for yield per hill, plant height, and yield per spike, and a high proportion of additive × additive epistasis for spikes per hill, days to heading, and 100-seed weight. Seven doubled-haploid lines were selected from different high-yielding crosses represented by C1DH lines...
19 citations
Journal Article•
TL;DR: Fifteen genotypes were crossed in a partial diallel fashion and Combining ability analysis showed that mean squares due to general combining ability (gca) and specific combining ability(sea) were significant, the former being larger in magnitude than the latter in both environments.
Abstract: Fifteen genotypes were crossed in a partial diallel fashion. Combining ability analysis.for seven characters in two environments showed that mean squares due to general combining ability (gca) and specific combining ability (sea) were significant, the former being larger in magnitude than the latter in both environments. However, gca/sca σ2g/σ2s the ratio was higher for days to heading, plant height, number of grains/ear and 1000-grain weight. The parents HD 2009 and WH 147 far total biomass, number of grains/ear and grain yield; Raj 821 and Sonalika for early flowering, shorter height and 1000-grain weight; hd 2122 for days to heading and plant height; P 1200 for days to heading and 1000-griin weight: and Kharchia-65 for tiller number and total biomass were good general combiners.
14 citations
TL;DR: Seven highly inbred lines of White Leghorn chickens were used in a near complete diallel mating plan during eight years, showing large differences between line effects could be found in all traits and a negative correlation between reciprocal effects of egg weight and body weight.
Abstract: Seven highly inbred lines of White Leghorn chickens were used in a near complete diallel mating plan during eight years. The lines originated from three different base populations selected for egg weight. Average inbreeding coefficients of parents of chicks hatching in successive years were 0.75, 0.80, 0.84, 0.86, 0.89, 0.91, 0.93 and 0.94. The composition of line, specific combining ability and reciprocal effects and their estimated values are given. These effects were estimated for age at first egg (AFE), average weight of all eggs laid to 40 weeks (EW40), body weight at 40 weeks (BW40), number of eggs to 40 weeks (EP40) and number of eggs between 41 and 60 weeks (EP60). Records of 3247 hens surviving to 40 weeks and of 3133 birds to 60 weeks could be used. Large differences between line effects could be found in all traits. They were only partly due to the preceding selection in the base populations. All specific combining effects were in the expected direction, negative for AFE and positive for EW40, BW40, EP40 and EP60. Recovery of inbreeding depression inflated these effects rather substancially. Average heterosis, defined as the relative superiority of a line combination over the mid parent value, was −11.3%, 5.8%, 7.8%, 45.1% and 35.8% for AFE, EW40, BW40, EP40 and EP60 respectively. One line showed a relative superiority in AFE of -19.3% compared to about −7.9% for all other combinations. Reciprocal or sex-linked effects were generally smaller in all traits than specific combining effects, they were considerably smaller in AFE, EP40 and EP60. General reciprocal effects could be found for several lines in one or more traits. Offspring of two lines, when used as sire lines, showed a negative correlation between reciprocal effects of egg weight and body weight.
TL;DR: It is suggested that a population improvement is possible by breeding for low phytic acid cultivars of pearl millet, and both additive and non additive gene effects were significant.
Abstract: The genetics of phytic acid content in pearl millet (Pennisettum typhoides (Burm) S & H) was studied using a 12 parent diallel. The analysis of variance of diallel progenies exhibited significant genotypic differences. Different analyses, i.e., combining ability analysis, analysis of variance of diallel tables and genetic component analysis, showed that both additive and non additive gene effects were significant. It is suggested that a population improvement is possible by breeding for low phytic acid cultivars of pearl millet.
TL;DR: Based on its good statistical performance and wide feasibility, the single population method is recommended, and the diallel method provides the most information on genetic components of variation.
Abstract: Experimental designs for measuring the effects of single loci on quantitative traits are compared for statistical properties. The designs tested are single population, combined strains, multiple strains, diallel of strains, and co-isogenic strains. Testing was done by simulating population genotypic and phenotypic arrays. Statistical properties measured are type I error, power, bias and efficiency. The relative ranking of designs is consistent for all properties and over eight conditions examined. The co-isogenic design is superior, followed closely by the single population method. The other three designs are similar in ability, with the diallel design somewhat superior. Based on its good statistical performance and wide feasibility, the single population method is recommended. The diallel method provides the most information on genetic components of variation.
TL;DR: The phenotypic and genotypic properties of second cycle hybrids are predicted from the means and variances of the F2 generation of two crosses between pairs of inbred varieties of Nicotiana rustica and only few of the second cycle hybrid lines will be superior to the best first cycle inbred lines.
Abstract: The phenotypic and genotypic properties of second cycle hybrids are predicted from the means and variances of the F2 generation of two crosses between pairs of inbred varieties of Nicotiana rustica (V1 × V5 and V2 × V12). The predicted properties are compared with the observed properties of the second cycle hybrids generated by crossing the first cycle recombinant inbred lines with the F1 of the original cross (the L3 generation of an inbred line triple test cross) which, in the absence of a linkage disequilibrium, are identical with the second cycle hybrids produced as a diallel set of crosses among the first cycle inbred lines. In the presence of a linkage disequilibrium the diallel set of crosses has a smaller linkage bias than the inbred line × F1 crosses. The agreement between the predicted and observed phenotypic properties of the second cycle hybrids is good over a wide range of characters in both crosses. The overall correlations between the observed and expected proportions are 0·81 and 0·88 for the V1 × V5 and V2 × V12 crosses, respectively. Furthermore, the genotypic predictions show that only few of the second cycle hybrids and second cycle inbred lines will be superior to the best first cycle inbred lines which were themselves superior to their own better parents and their heterotic F1's. Genetical explanations of the origins of the superior derivatives of an initial cross are explored using a development of the standard notation of Mather and Jinks (1982).
TL;DR: A modified diallel cross is used to estimate effects of alleles at the esterase 6 locus, relative to strain and environmental variance, in Drosophila melanogaster, and these alleles show a significant additive effect on mating speed, but not on the other traits.
Abstract: A modified diallel cross is used to estimate effects of alleles at the esterase 6 locus, relative to strain and environmental variance, in Drosophila melanogaster. Three strains homozygous for Est 6 (s) and three homozygous for Est 6 (F) were crossed in all 36 combinations. Male progeny were scored for mating speed, copula duration and esterase 6 enzyme activity, and all progeny for developmental time. These alleles show a significant additive effect on mating speed, but not on the other traits. Copula duration, developmental time and enzyme activity show additive strain genetic variance. Enzyme activity and developmental time also have maternal or X-chromosome strain variance, and these two traits are significantly correlated. This modified diallel method is generally useful because it permits the partition of trait variance into additive and dominant locus, background genetic and environmental components.
TL;DR: The strong positive association of callus growth with seed yield indicates the possibility of using this system for mass screening and selection of superior hybrids.
Abstract: Studies on callus growth and shoots/cotyledon, using seven different genotypes of pigeonpea and their hybrid progenies, revealed continuous variation for these traits. Hence, the type of gene action influencing in vitro cell proliferation and differentiation has been investigated in a diallel analysis of seven pigeonpea genotypes. Highly significant average heterosis was recorded for callus growth and seed yield/plant. In general, the F1 hybrids which showed heterosis for callus growth also exceeded their better parent for yield/ plant. Combining ability analysis revealed both additive and non-additive gene effects for callus growth, while number of shoots/cotyledon was mostly governed by non-additive gene effects. The genotype, ‘ICP 7035’, was the best general combiner for callus growth and shoot forming capacity of cotyledons. Two cross combinations, ‘7186’ב6974’ and ‘7035’בT-21’, showed maximum SCA effects for callus growth and shoots/cotyledon. Callus dry weight was positively correlated with seed yield/plant and seedling weight. The strong positive association of callus growth with seed yield indicates the possibility of using this system for mass screening and selection of superior hybrids.
TL;DR: There was a high degree of agreement between the results obtained from factorial mating design and diallel cross analyses showing thereby that the former provides almost equivalent genetic information to the latter.
Abstract: For studying the inheritance of metric traits, diallel cross and factorial mating designs are commonly used. Since factorial mating design is less restrictive in crossing plans, the genetic information drawn from it was compared with that from a diallel cross. The comparison was made using graphical, genetic components and combining ability analyses for grain yield, grain weight and spike length in a field experiment of bread wheat (Triticum aestivum L.). Analyses were made on a nine parent diallel cross and a 4 ♀ × 5 ♂ factorial mating design which was sampled from the diallel cross. In general, there was a high degree of agreement between the results obtained from factorial mating design and diallel cross analyses showing thereby that the former provides almost equivalent genetic information to the latter.
Journal Article•
TL;DR: A 6x6 diallel set excluding reciprocals and involving contrasting parents in respect of gel consistency was made and the observations made in the parents, F 1′s and F 2′s were subjected to combining ability and heterosis analysis.
Abstract: A 6x6 diallel set excluding reciprocals and involving contrasting parents in respect of gel consistency was made and the observations made in the parents, F 1′s and F 2′s were subjected to combining ability and heterosis analysis.
Journal Article•
TL;DR: Twelve parent diallel analysis in peanuts was conducted to study combining ability in respect of six quantitative traits and variances were highly significant for all the six characters and were higher in magnitude than the s.c.a. variances.
Abstract: Twelve parent diallel analysis in peanuts was conducted to study combining ability in respect of six quantitative traits. Variances due to g.c.a. were highly significant for all the six characters and were higher in magnitude than the s.c.a. variances, which were significant only for three characters. Both additive and non additive gene effects were important for plant height, pod yield and days to maturity and only additive gene effects were important for number of branches, number of developed and undeveloped pods. Cultivars Dh-3-30, JJS-4, EC-21120 and dwarf mutant could be used in breeding for improved varieties of peanuts in general and cultivars TG-1. Sbulamit, Dh-3-30 and Dwarf mutant in improving the pod yieldper se.
TL;DR: An incomplete diallel cross with selfs and reciprocals was made with twelve cultivars of Gerbera jamesonii, but the phenotypic performance of parents was poorly related to their breeding value (measured on seedlings).
Abstract: An incomplete diallel cross with selfs and reciprocals was made with twelve cultivars of Gerbera jamesonii. Very significant differences occurred between GCA's of the parents for cut flower yield, earliness and number of lateral shoots. The selfs were mainly responsible for the significant SCA's.
Journal Article•
TL;DR: The nature of combining ability in sesame was studied in a set of 10x10 diallel and variances indicate that the inheritance of these characters is predominantly governed by additive and additive × additive epistatic components of genetic variance.
Abstract: The nature of combining ability in sesame was studied in a set of 10x10 diallel. Variances for g.c.a., s.c.a. and reciprocal effects were significant. The higher magnitude of g.c.a. than s.c.a. variances indicate that the inheritance of these characters is predominantly governed by additive and additive × additive epistatic components of genetic variance. SH 50, T12, B. local and SH 62 were the best general combiners when 4 to 6 characters were considered at a time and T2xN32, Patan 64xSH 62 and Patan 64xT13 showed high s.c.a. effects for yield. The superior combinations involved all the three possible combinations between parents of high and low general combining ability effects i.e. high × high; high × low and low × low. in general, the superior combinations involved at least one high general combining parent. Significant variance for reciprocal effects indicated the presence of maternal effects.
Journal Article•
TL;DR: For combining high seed yield with high protein content, multiple cross followed by further intermatings among desirable segregants has been proposed and provides valuable genetic information for early assessment of parents for hybridization programmes and also for deciding efficient breeding procedure leading to rapid improvement in seed yield and protein content in pea.
Abstract: Combining ability of yield, its components and protein content was worked out from F1 and F2 generations of a diallel cross involving ten parents of pea. It showed significant additive and nonadditive genetic effects for all the characters, namely, days to flowering, plant height, branches per plant, pods per plants, seeds per pod, pod length, days to maturity, seed yield per plant, harvest index, and protein content in both F1 and f2 generations. Parents T 163,6113 and P 209 were good general combiners for yield, and EC 33866 and BR 12 for protein content. The highest mean performance and sea effects were recorded in the cross T I63×EC 33866 and BR 12×P 209 for yield and protein contents, respectively. The high performing cross combinations involving at least one good general combiner could be expected to produce transgressive segragants and thus need to be exploited in breeding programmes. For combining high seed yield with high protein content, multiple cross followed by further intermatings among desirable segregants has been proposed. The present analysis of a 10 × 10 diallel cross provides valuable genetic information for early assessment of parents for hybridization programmes and also for deciding efficient breeding procedure leading to rapid improvement in seed yield and protein content in pea.
13 Nov 1985
TL;DR: Analysis of data from a 9 X 9 diallel, involving parents with different degrees of resistance to the pests, revealed that additive genetic variance was significant and greater than nonadditive genetic variance for both Atherigona soccata and Contarinia sorghicola.
Abstract: Analysis of data from a 9 X 9 diallel, involving parents with different degrees of resistance to the pests, revealed that (1) additive genetic variance was significant and greater than nonadditive genetic variance for both Atherigona soccata and Contarinia sorghicola, (2) general combining ability variances were greater than specific combining ability (SCA) variances for both pests, (3) recessive genes conditioned susceptibility to A. soccata while dominant genes conditioned susceptibility to C. sorghicola, (4) desirable general combiners did not exhibit good SCA effects, (5) narrow-sense heritability for resistance was low for both pests, and (6) the cross S Girl MR1 X IS6394 showed the desired SCA effects for both pests and yielded c. 30% more than the best control, CSH8R
TL;DR: Genetic analyses of flue-cured tobacco leaf physical characteristics and chemical characteristics conducted on a five parent diallel set evaluated at the Delhi Research Station in a randomized block design over a 2-year period suggested additive genetic variance as the main source of genetic variation.
Abstract: Genetic analyses of flue-cured tobacco leaf physical characteristics (percent lamina, lamina weight, and filling value) and chemical characteristics (percent total alkaloids, reducing sugars, nitrogen, ash, and cellulose) were conducted on a five parent diallel set (excluding reciprocals) evaluated at the Delhi Research Station in a randomized block design over a 2-year period. The ANOVA indicated that there was variance associated with the genetic source for all characteristics except filling value. Griffing's analysis for variances owing to general and specific combining abilities suggested additive genetic variance as the main source of genetic variation. Variances owing to specific combining ability for all traits were exceeded by the variance of the estimates indicating dominance to be of no major consequence in the expression of these physical and chemical traits. Total alkaloids and percent nitrogen expressed maximum heritability, and Wr–Vr graphs supported the conclusions. Parental diversity was e...
TL;DR: It is concluded that cell-division rate (cell number) is conditioned largely by nonadditive type genes and that beet root heterosis is due primarily to increases in cell number rather than cell size.
Abstract: Differentiation in sugarbeet (Beta vulgaris L.) roots is completed in the first 4 to 5 weeks of growth. From then on, growth is by simultaneous cell division and cell expansion. Selection for root yield may exert selection pressure on either cell-division rate or cell expansion or both. The degree of selection pressure applied to either of these two cellular parameters depends on their respective inheritance behavior and the breeding and selection methods used. This study was initiated to determine the inheritance of cell-division rate (cell number). Cell-division rate was based on the number of cells across the radius of a cross section of 20- to 28-day-old plants. Heterosis was determined in progeny of six males crossed to line L29, two-by-five females ✕ males crosses and a five-parent diallel. Genotypic variance estimates were made in a three-by-three female ✕ males cross and the five-parent diallel. Cell number showed significant heterosis in all but two hybrids tested. Both general and specific combining ability effects were significant for cell number, with specific combining ability showing the greatest significance. Estimates of nonadditive genetic variance accounted for between 75 and 95% of the total genetic variance. It is concluded that cell-division rate (cell number) is conditioned largely by nonadditive type genes and that beet root heterosis is due primarily to increases in cell number rather than cell size. Breeding and selection methods that capitalize on nonadditive genetic variation will, therefore, increase sugarbeet root yield by increasing cell-division rate.
TL;DR: The study of agronomic characters of healthy and virus diseased plants in a diallel cross program concerning five different varieties of bean shows that in both cases the general combining ability for yield and its components usually has positive or negative significant values.
Abstract: The study of agronomic characters of healthy and virus diseased plants in a diallel cross program concerning five different varieties of bean, shows that in both cases the general combining ability...
TL;DR: The quantitative inheritance of flowering time in autumn-sown subterranean clover was studied in a 13 x 13 diallel cross in a Mediterranean-type environment and flowering time was shown to be highly heritable with a low average degree of dominance.
Abstract: The quantitative inheritance of flowering time in autumn-sown subterranean clover (Trifolium subferraneum L. ssp. subterraneum) was studied in a 13 x 13 diallel cross in a Mediterranean-type environment. Flowering time was shown to be highly heritable with a low average degree of dominance, which was predominantly in the direction of earliness. Covariance/variance ( WT/V;) regression analysis indicated early flowering to be conditioned mostly by dominant alleles, and lateness mostly by recessives. The alleles were slightly asymmetrically distributed among the parents, with recessives marginally in excess. Inadequacy of the additive-dominance model, on which the Birmingham diallel analysis is based, was detected by a significant departure from unity of the joint regression coefficient and the heterogeneity among arrays of (Wr - VJ values, which could be ascribed to and overcome by omitting two late-flowering parents from the diallel cross.