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1.
Photochemical activity of isolated mesophyll chloroplasts was measured as Hill reaction activity (HRA) and photosystem 1 (PS1)
activity in three diallel crosses of maize (Zea mays L.) inbred lines and F1 hybrids. Statistically significant differences between genotypes together with positive heterotic effect in F1 generation were found for both traits studied. These differences were more pronounced when HRA or PS1 activity was expressed
per leaf area unit or dry matter unit compared to the expression per chlorophyll content unit. Analysis of variance showed
that both the genetic and non-genetic components of variation in the photochemical activity of isolated mesophyll chloroplasts
are present in all three diallel crosses examined. The positive heterosis in F1 hybrids probably arises from non-additive genetic effects of a positive dominance type. Additive genetic effects were also
statistically highly significant. We found no differences between reciprocal crosses.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
2.
Evaluation of circulant partial diallel crosses in maize 总被引:1,自引:0,他引:1
Dr. B. S. Dhillon J. Singh 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1978,52(1):29-37
Summary The present study was conducted in maize (Zea mays L.) on crosses among 20 diverse parents. The materials were evaluated in four different environments for eight characters. Combining ability analysis was carried out following diallel and partial diallel crosses. The number of crosses per parent (s) varied from 3 to 19 and the results were studied to identify the critical value of s that would provide an adequate information with minimum resources. The S5 partial diallel was as good as the S19 for the detection of differences among general combining ability (GCA) effects. Even the S3 gave adequate information in the case of characters with high heritability. However, partial diallel analysis was less efficient in detecting the differences due to specific combining ability (SCA) effects. These results varied with environments, and characters with low heritability were more prone to misinterpretation. GCA effects showed fluctuations in partial diallel analysis which were more pronounced in S5 and S3, particularly for characters with low heritability. The average standard error of difference between GCA effects increased with a decrease in s, with a steep slope for s < 7. The partial diallel analysis was more efficient for the estimation of the variance component of GCA than for SCA, as the estimate of SCA was biased upwards. Estimates of broad sense heritability obtained from the partial diallels agreed with the full diallel analysis better than the narrow sense estimates. Smaller partial diallels gave erratic estimates of heritability, particularly for the characters with low heritability. 相似文献
3.
This study was conducted to determine the reciprocal effects for anther culture response in wheat (Triticum aestivum L.) using a set of 4 × 4 full diallel crosses. Both reciprocal and nuclear genetic effects were highly significant for anther
culture response and useful for selection and breeding purposes. General combining ability (GCA) effects were predominant
for all investigated anther culture traits. Also, significant differences for specific combining ability (SCA) effects were
detected between reciprocal crosses. Although significant reciprocal differences for responding anther, callus number and
green plant regeneration were recorded in some reciprocal crosses, there were no significant reciprocal differences for albino
plant regeneration. The use of one parent as male or female could lead to change at the production of green plants from the
F1 hybrids and screening of inbred lines for response to anther culture, without reciprocal effects, could decrease the utilization
of breeding material. 相似文献
4.
The combining abilities of field resistance to peanut bud necrosis disease (PBND) caused by Peanut bud necrosis tospovirus (PBNV) were examined to understand the type of gene action governing resistance to the disease, and to identify peanut lines suitable for use as parents in a PBND‐resistance breeding programme. The Ft and F2 progenies from a six‐parent diallel cross and their parents were evaluated under field conditions. They were assessed for disease incidence at 30, 40, 50 and 60 days after planting (DAP), and reactions of the lines to the disease could be best differentiated at 50 and 60 DAP. Results indicated highly significant general combining ability (GCA) effects for PBND incidence in F1 and F2 generations. Specific combining ability (SCA) and reciprocal effects were also found to be significant, but their relative contributions to variation among crosses were much less than those of GCA effects. These results suggested that the type of gene action governing resistance to PBND was mainly additive, and selection for PBND resistance in these populations should be effective. Strong correlation coefficients between parental means and GCA effects for disease incidence were seen in both Ft and F2 generations, suggesting that per se performance of the parental line could be used as a predictor of the capability of the line to transmit its PBND‐resistant attribute to progenies. The reciprocal effects were in favour of using resistant lines as female parents. The peanut lines ICGV 86388, 1C 10 and 1C 34 were found to be suitable for use in a PBND–resistance breeding programme. 相似文献
5.
H. Tyson 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1989,77(2):260-270
Summary Mean seed weight data were obtained from the F1 and F2 of a six-by-six diallel cross with flax (Linum usita-tissimum L.). Pronounced reciprocal differences appeared in the F1, but had largely disappeared by the F2. The genetic control of mean seed weight was examined using two types of analysis of variance. The models underlying both analyses were fitted to the data by matrix methods supplying weighted least-squares estimates of the parameters in the models. Weights, the use of which dealt with the problem of variation in the reliability of means, were the reciprocals of the variances of individual cell (cross/self) means in the diallel data table. Elimination of redundant parameters supplied the minimum adequate models for each analysis type. Dominance was apparently masked by the large transient maternal effects in the F1, but surfaced in the F2, where dominance was towards larger mean seed weight. This may be coupled with findings elsewhere of possible advantages for larger seed weights to speculate on a role in preserving infrequent hybrid progeny among inbreeding (flax) species. Maternal effects producing larger seed size, plus dominance with the same result might be valuable, in conjunction with growth and competitive advantages conferred by larger seed, in preventing early elimination of rare hybrids. 相似文献
6.
The expected values of average degree of dominance in F2 and later segregating generations of a diallel cross have been mathematically derived, and compared to its value in F1 generation. The interpretation of intercepts on Wr axis, a measure of average degree of dominance, differed in segregating generations from that of F1 at origin, and between origin and tangent in Wr, Vr-graph. 相似文献
7.
In this paper the analysis of genotypes obtained in diallel crossing system, including parents, one set of F1s and reciprocal F1's, is given. This analysis is presented for data obtained from the experiments laid out in block designs. The analysis of variance, estimator of reciprocal effects, estimators of general and specific combining abilities as well as statistics for testing of hypotheses concerning those parameters are given. 相似文献
8.
In this paper the analysis of genotypes obtained in a diallel crossing system, including parents, one set of F1′s and reciprocal F1′s, is given. This analysis is presented for data obtained from the experiments carried out in a block design in which block effects are random. The analysis of variance, estimators of reciprocal effects, estimators of general and specific combining abilities are considered. Also statistics for testing hypotheses concerning some genetical parameters are given. 相似文献
9.
Summary A diallel study involving reciprocal crosses of four genotypes (IR8, 36, 54, and 64) was carried out to understand the genetic
mechanism of plant regeneration from immature embryo-calli in rice. Regeneration frequency (% of calli that produced plants)
varied from a high of 86% for IR54 to a low of 0% for IR36, while regenerated plants per embryo numbered from 0 to 7 when
these same IR lines and the F1 hybrids were compared. Combining ability analysis revealed that both nuclear (with both additive and dominant effects) and
cytoplasmic genes are important in controlling regeneration in rice. Parental lines and F1 hybrids with high ability to regenerate
were identified. 相似文献
10.
M. R. Ghannadha I. L. Gordon M. G. Cromey J. M. McEwan 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,90(3-4):471-476
A half diallel was made amongst five wheat (Triticum aestivum L.) genotypes of which one was susceptible, while the others had adult-plant resistance, to stripe rust (Puccinia striiformis West.). The five parent and ten F1 progeny were grown in the glasshouse and were inoculated with three rust pathotypes at the seedling stage. The latent period was measured on the first leaf. Two procedures were used to analyze the half diallel. Both methods showed that the average effects of alleles were of much greater importance than was dominance in conditioning resistance in response to two of the pathotypes, while for the third pathotype dominance was important. Resistance was conditioned by partial dominance for two pathotypes whereas for the third it was determined by full dominance. Broad-sense heritabilities range from 60–73% and the number of genes involved was different (from 1 to 4), depending on the pathotype. 相似文献
11.
R. M. HABGOOD 《The Annals of applied biology》1974,77(2):191-200
The inheritance of partial resistance to Rhynchosporium secalis, which appears to be race non-specific, was studied in a diverse range of European spring barley cultivars. Data from the F2 generation of a 6 × 6 diallel cross and the F3 generation of three crosses selected from this diallel set suggested that resistance was complex in inheritance, the results being incompatible with any hypothesis involving less than four genes. The F2 studies indicated that both dominant and recessive genes were active in conferring resistance, and that there were significant additive gene effects. Transgressive segregation occurred in all cross combinations in the F3 material. Consequently the alleles conferring resistance were not completely concentrated in the most resistant cultivar studied (cv. Proctor). Heritability estimates obtained from F2 and F3 material suggested that field selection was of limited reliability, even when spreader drills were incorporated amongst the segregates. Single-plant selection (in F2) was considered to be of little value, and the results of Fa head-row tests would require confirmation by replicated tests in subsequent generations. 相似文献
12.
Three different races of lepidopteron silk moth Bombyx mori were used in reciprocal and inter se crosses to determine heterosis effects at F1 and recombination loss at the F2 generation for three fitness traits (fecundity, larval duration, survival rate) and four productivity traits (larval weight, cocoon weight, shell weight, filament length). Eleven mating types were represented in the present study, including three pure breeds and a variety of F1 and F2 populations arising from regular and reciprocal crosses, respectively. Equations were derived to evaluate heterosis, maternal and overdominance effects for the above traits. Estimates of heterosis and overdominance effects revealed significant heterosis effects for all the traits, but overdominance was only seen for larval duration (favorable effect) and survival rate (unfavorable effect). Maternal effects were significant for the majority of the traits under study. The results revealed significant reduction for all the quantitative traits from F1 to F2, except for larval duration. The most obvious explanation for the reduction of fitness parameters and productive traits is the reduction in heterozygosity from F1 to F2 (it is expected that one half of the heterozygosity of F1 is lost in F2). For larval duration this explanation seems insufficient and breakdown of epistatic gene effects (i.e. recombination loss) has been suggested. 相似文献
13.
J. Lee P. J. Kaltsikes 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1973,43(5):226-231
Summary Correlation, stepwise multiple regression and factor analyses were conducted on grain yield and a number of agronomic characters in the parental, F
1 and F
2 families originating from a 10 X 10 diallel cross in durum wheat. For the F
1 diallel, the correlation analysis indicated that the number of spikes and kernels per plant and 1,000 kernel weight had the highest correlations with grain yield; for the F
2 diallel, the number of spikes and kernels per meter, 1000 kernel weight and plant height showed most striking correlations with same.Stepwise multiple regression analysis indicated that, for the F
1 diallel, number of kernels per plant, 1000 kernel weight and days to maturity were the most potent predictor variables for grain yield, accounting for 78% of its variability. For the F
2 diallel, the number of kernels and number of spikes per meter, 1000 kernel weight and number of kernels per spike were the most potent predictors for grain yield, accounting for 91 % of its variability. Five common factors were extracted which explained 98.8% and 98.1% of the total variance in the F
1 and F
2 diallel, respectively. However, the importance of each of the five factors and the characters which loaded highly on each of them differed from generation to generation.Contribution No. 323 from Plant Science Department, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada. 相似文献
14.
Analysis of a combined F1/F2 diallel cross in wheat 总被引:2,自引:0,他引:2
J. Hill W. W. Wagoire R. Ortiz O. Stølen 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(6-7):1076-1081
Analysis of a conventional diallel cross offers only perfect-fit estimates of the genetic components of variation, but no
test for the goodness of fit of the model based on these estimates. When F2 progenies are available, however, combining F1 and F2 diallels in a single experiment overcomes these problems. Least-squares estimates of these components can be calculated,
errors attached to them and the goodness of fit of the resultant model tested. This analysis was applied to data on the severity
of yellow rust infection in an F1/F2 half-diallel cross among eight bread wheat lines adapted to the East African highlands. After removing two interacting arrays,
genetic analysis indicated that an additive/dominance model of gene action satisfactorily explained the variation observed
among the remaining six parents and their progenies, in both the individual F1 and F2 diallels and the combined F1/F2 diallel. Resistance to yellow rust was dominant to susceptibility and genes for increased resistance were more frequent.
Received: 25 May 2000 / Accepted: 31 July 2000 相似文献
15.
Analysis of genetic effects of major genes and polygenes on quantitative traits I. Genetic model for diploid plants and animals 总被引:5,自引:0,他引:5
Lou XY Zhu J 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(2-3):414-421
A genetic model was proposed to simultaneously investigate genetic effects of both polygenes and several single genes for
quantitative traits of diploid plants and animals. Mixed linear model approaches were employed for statistical analysis. Based
on two mating designs, a full diallel cross and a modified diallel cross including F2, Monte Carlo simulations were conducted to evaluate the unbiasedness and efficiency of the estimation of generalized least
squares (GLS) and ordinary least squares (OLS) for fixed effects and of minimum norm quadratic unbiased estimation (MINQUE)
and Henderson III for variance components. Estimates of MINQUE (1) were unbiased and efficient in both reduced and full genetic
models. Henderson III could have a large bias when used to analyze the full genetic model. Simulation results also showed
that GLS and OLS were good methods to estimate fixed effects in the genetic models. Data on Drosophila melanogaster from Gilbert were used as a worked example to demonstrate the parameter estimation.
Received: 11 November 2000 / Accepted: 2 May 2001 相似文献
16.
Philip Welbergen Folchert R. van Dijken Wim Scharloo Wolfgang Khler 《Evolution; international journal of organic evolution》1992,46(5):1385-1398
The genetic analysis of sexual isolation between the closely-related species Drosophila melanogaster and Drosophila simulans involved two experiments with no-choice tests. The efficiency of sexual isolation was measured by the frequency of courtship initiation and interspecific mating. We first surveyed the variation in sexual isolation between D. melanogaster strains and D. simulans strains of different geographic origin. Then, to investigate variation in sexual isolation within strains, we made F1 diallel sets of reciprocal crosses within strains of D. melanogaster and D. simulans. The F1 diallel progeny of one sex were paired with the opposite sex of the other species. The first experiment showed significant differences in the frequency of interspecific mating between geographic strains. There were more matings between D. simulans females and D. melanogaster males than between D. melanogaster females and D. simulans males. The second experiment uncovered that the male genotypes in the D. melanogaster diallel significantly differed in interspecific mating frequency, but not in courtship initiation frequency. The female genotypes in the D. simulans diallel were not significantly different in courtship initiation and interspecific mating frequency. Genetic analysis reveals that in D. melanogaster males sexual isolation was not affected by either maternal cytoplasmic effects, sex-linked effects, or epistatic interaction. The main genetic components were directional dominance and overdominance. The F1 males achieved more matings with D. simulans females than the inbred males. The genetic architecture of sexual isolation in D. melanogaster males argues for a history of weak or no selection for lower interspecific mating propensity. The behavioral causes of variation in sexual isolation between the two species are discussed. 相似文献
17.
R. M. Pandey 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1984,68(1-2):121-125
Summary Genetical studies on grain yield and its contributing traits were made in a six parent complete diallel in the F1 and F2 generations of one of the most widely grown grain species of grain amaranths (Amaranthus hypochondriacus L.). Graphical analysis indicated that epistasis exists for 1,000-grain weight in the F1. Grain weight/panicle, yield/plant and harvest index indicated absence of non-allelic gene interaction. The harvest index in the F1 and F2 and grain weight/ panicle, 1,000-grain weight, yield/plant in the F2 appeared to be controlled by overdominance effects. Higher grain yield appeared to be associated with dominant genes. Both additive and non-additive gene effects were responsible for the genetic variation in the diallel population. However, dominance variance was more important than additive variance in grain yield/ plant and harvest index in the F1 and F2. For 1,000-grain weight additive genetic variance was more important in the F1 and non-additive in F2. There was overdominance of a consistent nature in the two analyses for harvest index in the F1 and F2, grain weight/ panicle, 1,000-grain weight and yield/plant in the F2 and partial dominance for 1,000-grain weight in the F1. 相似文献
18.
J. E. Staub D. Globerson A. Genizi 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1989,78(1):143-151
Summary Reciprocal matings were made between two Cucumis sativus var. sativus L. inbred lines (WI 1606 and WI 2808) and two var. hardwickii (Royle) Alef. accessions (PI 215589 and PI 183967). Each case produced a series of reciprocal F1, F2, and BC1 and BC2 progenies which were used to evaluate seed dormancy in var. hardwickii. Under controlled conditions (25°±1°C and 85%±5% RH; 12 h fluorescent light, 30 mol s–1 m–2), no seed dormancy was observed in the var. sativus inbred lines 36 days following seed extraction from fruit. With rare exception, var. hardwickii accessions were dormant for at least 60 days. Seed dormancy in the F1 was absent 36 days post extraction, indicating that dormancy in var. hardwickii is conditioned by recessive genes present. Seed of some F1 progeny germinated between 36 and 50 days post-extraction, indicating the presence of transient dormancy or the more variable expression of the dormancy of var. hardwickii. No significant reciprocal differences in either germination rate or percentage were detected in either of the F1 and F2 progeny sets, suggesting lack of cytoplasmic or maternal control over these traits. It was estimated that three to seven factors or loci are involved with the expression of this trait depending on the method of calculation, and that a complex interaction between embryonic and non-embryonic tissue exists. Least square estimates indicate that both additive and dominance effects were important in the expression of dormancy. Comparison of theoretical geometric and arithmetic F2 means to observed F2 means also suggests that non-additive gene action contributes substantially to the observed variation. Broad-sense heritability ranged between 78 and 95%. 相似文献
19.
Inbred lines of maize selected as tolerant and intolerant to low-P stress using a sand-alumina culture medium were used to obtain F1 hybrids and advanced generations to be evaluated in diallel mating schemes and generation means analyses for the inheritance studies. Sand-alumina, a solid culture medium, which simulates a slow release, diffusion-limited P movement in soil solution was used in the inheritance studies. Tolerance to low-P stress conditions in maize seedlings is controlled largely by additive gene effects, but dominance is also important. 相似文献
20.
A. E. Melchinger H. H. Geiger F. W. Schnell 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1986,72(2):231-239
Summary Three flint and three dent maize (Zea mays L.) inbred lines, their possible F1 crosses, F2 and backcross progenies, and all possible three-way crosses were evaluated in a three-year experiment for yield, ear moisture, and plant height. The purpose was to estimate genetic parameters in European breeding materials from (i) generation means analysis, (ii) diallel analysis of generation means, and (iii) analysis of F1 and three-way cross hybrids. Method (i) was based on the F-metric model and methods (ii) and (iii) on the Eberhart-Gardner (1966) genetic model; both models extended for heterotic maternal effects.Differences among generation means for yield and plant height were mainly attributable to dominance effects. Epistatic effects were significantly different from zero in a few crosses and considerably reduced heterosis in both traits. Additive x additive and domiance x dominance effects for yield were consistently positive and negative, respectively. Significant maternal effects were established to the advantage of generations with a heterozygous seed parent. In the diallel analysis, mean squares for dominance effects were greater than for additive effects for yield and plant height but smaller for ear moisture. Though significant for yield and plant height, epistatic variation was small compared to additive and dominance variation. Estimates of additive x additive epistasis for yield were significantly negative in 11 of 15 crosses, suggesting that advantageous gene combinations in the lines had been disrupted by recombination in the segregating generations. The analysis of hybrids supported the above findings regarding the analysis of variance. However, the estimates of additive x additive epistasis for yield were considerably smaller and only minimally correlated with those from the diallel analysis. Use of noninbred materials as opposed to materials with different levels of inbreeding is considered the main reason for the discrepancies in the results. 相似文献