共查询到20条相似文献,搜索用时 15 毫秒
1.
W. R. Deaton S. G. Metz T. A. Armstrong P. N. Mascia 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1987,74(3):334-338
Summary Anther-culture response was examined among three spring wheat (Triticum aestivum L.) cultivars to evaluate the genetic component of response and to determine whether androgenetic performance could be improved by selection. The three lines, the three possible F1's among the three lines, their F2's, and the backcrosses to the parents were evaluated for callus production and regeneration capacity. Significant variation was observed among the generations of the three crosses for callus formation. Genetic variation for regenerability was nonsignificant. Callus production was negatively correlated (-0.24) with regeneration capacity. The random variation in the study was too great to determine whether major-gene differences for antherculture response exist among the three lines by examining population distributions. When the material was evaluated for quantitative gene effects, the estimates for the additive gene effects were generally greater than the estimates for the dominance gene effects for callus formation. Only the Pavon x Chris cross, however, exhibited a significant narrow sense heritability estimate for callusing response (0.94). Due to the large component of random variation and the varying selection potential among crosses for androgenetic performance, improving anther-culture response in wheat by selection could prove difficult unless the anther-culture process itself selects for response traits at the gametic level. 相似文献
2.
A probit analysis of the dosage-response of two isolates of Spodoptera frugiperda to a single nuclear polyhedrosis virus revealed a greater than 5-fold difference in the LD50. The response of F1 progeny of reciprocal crosses between the two parental isolates demonstrated that resistance to the virus is not sex-linked. The LD50 values of F1 and F2 backcrosses suggest that the major variation in resistance is due to a single gene or genes that lack dominance. 相似文献
3.
C. W. Deren K. H. Quesenberry 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1989,78(6):825-830
Summary Induction of flowering by photoperiod was studied in the parental, F1, F2, and reciprocal backcross generations of crosses between three photoperiod-responsive Aeschynomene americana L. lines. Generation means appeared additive. Analysis with Mather and Jinks' scaling tests showed little or no epistasis and indicated that an additive-dominance model was adequate. Partitioning components of variation revealed that nearly all variation was additive genetic with dominance and environmental variation negligible. An additive genetic model with two loci, each with two alleles and all alleles having equal net effect, was tested using Power's partitioning method. Results demonstrated that the model fit the data and that there is a major additive genetic system controlling flowering in these crosses, with minor genetic and environmental influences present. Selection for flowering at a desired day length should be feasible.Accepted by A.R. HallauerFlorida Agricultural Experiment Station, Journal Series No. 9251 相似文献
4.
M. N. Inagaki G. Varughese S. Rajaram M. van Ginkel A. Mujeeb-Kazi 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(4):550-556
Yield performance of each group of ten spring bread wheat lines selected by doubled haploid (DH), single-seed descent (SSD)
and pedigree selection (PS) methods from three F1 crosses was compared with the aim of evaluating the DH method in breeding programs. Populations of 65–97 DH lines and 110
SSD lines per cross were used for selection. PS lines were developed by repeated selections from 1500 F2 plants. Yield evaluation was performed at the F6 generation of SSD and PS lines along with DH lines in a 2-year field experiment. It took only 2 years from the planting of
wheat materials for DH production to the planting of selected DH lines for yield evaluation. There was no significant difference
in grain yield between DH lines and PS lines selected from an F1 cross whose parental varieties were closely related in their pedigrees. In two crosses with low coefficients of parentage
and a large variation in their progenies, grain yield of selected DH lines was significantly lower than those of selected
SSD and PS lines. These results confirm that the DH method can save time in obtaining recombinant inbred lines ready for yield
evaluation. However, a larger DH population is required to achieve the same level of genetic advance with the PS method in
crosses containing greater genetic variation.
Received: 23 December 1997 / Accepted: 12 March 1998 相似文献
5.
Simple line crosses, for example, backcross and F2, are commonly used in mapping quantitative trait loci (QTL). However, these simple crosses are rarely used alone in commercial plant breeding; rather, crosses involving multiple inbred lines or several simple crosses but connected by shared inbred lines may be common in plant breeding. Mapping QTL using crosses of multiple lines is more relevant to plant breeding. Unfortunately, current statistical methods and computer programs of QTL mapping are all designed for simple line crosses or multiple line crosses but under a regular mating system. It is not straightforward to extend the existing methods to handle multiple line crosses under irregular and complicated mating designs. The major hurdle comes from irregular inbreeding, multiple generations, and multiple alleles. In this study, we develop a Bayesian method implemented via the Markov chain Monte Carlo (MCMC) algorithm for mapping QTL using complicated multiple line crosses. With the MCMC algorithm, we are able to draw a complete path of the gene flow from founder alleles to their descendents via a recursive process. This has greatly simplified the problem caused by irregular mating and inbreeding in the mapping population. Adopting the reversible jump MCMC algorithm, we are able to simultaneously search for multiple QTL along the genome. We can even infer the posterior distribution of the number of QTL, one of the most important parameters in QTL study. Application of the new MCMC based QTL mapping procedure is demonstrated using two different mating designs. Design I involves two inbred lines and their derived F1, F2, and BC populations. Design II is a half-diallel cross involving three inbred lines. The two designs appear different, but can be handled with the same robust computer program. 相似文献
6.
J. F. HOROBIN 《The Annals of applied biology》1986,108(1):199-204
Results are reported of crossing a dwarf seed stalk line (mean height 44.8 cm) from Israel with five inbred lines of the Rijnsburger type each having normal tall seed stalks (mean heights 83.1–105.9 cm). The seed stalk height of F1 generations from these crosses was slightly greater than that of the Rijnsburger parents but segregation occurred in the F2 giving plants which could be considered ‘dwarf’ and ‘normal’ with respect to seed stalk height. Selfing individual F2‘dwarf’ plants produced F3 progenies whose mean heights were in the dwarf range, and were significantly correlated with those of their F2 parent. The results obtained in the F2 and F3 families suggest that although a major recessive gene for dwarfness may be present, substantial minor gene and environmental variation is also involved. 相似文献
7.
A. Menkir P. J. Bramel-Cox M. D. Witt 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,89(2-3):233-239
The incorporation of exotic germ plasm into breeding populations can broaden and diversify the genetic base of adapted genotypes. To more effectively utilize the genetic resources existing in Sorghum bicolor (L.) Moench, a rapid and efficient method of incorporating exotic genotypes into adapted populations is needed. Therefore, this study was conducted to compare the effectiveness of backcrossing to a broad-based population versus backcrossing to an inbred line for developing improved lines from adapted x exotic crosses. A wild sorghum, a cultivated landrace, and a converted sorghum line were crossed to an inbred line (CK60) and a broad-based population (KP9B). After two generations of backcrossing to the respective adapted parent, 50 F2 lines were derived from each of the backcross generations of every mating and evaluated at three test environments. Backcrossing to an inbred line (CK60) gave fewer high-yielding segregates and generated less genetic variation than backcrossing to a population (KP9B). Also, the number of agronomically acceptable lines derived from each CK60 mating was fewer than that derived from the corresponding mating with KP9B. Overall, the use of a broad-based population as an adapted recurrent parent for introgressing exotic genotypes may provide good opportunities for developing suitable inbred lines from adapted x exotic backcrosses.Contribution no. 93-499-J from the Kansas Agricultural Experiment Station 相似文献
8.
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
9.
The analysis of reciprocal genetic crosses between resistant Helicoverpa armigera strain (BH-R) (227.9-fold) with susceptible Vadodara (VA-S) strain showed dominance (h) of 0.65-0.89 and degree of dominance (D) of 0.299-0.782 suggesting Cry1Ac resistance as a semi-dominant trait. The D and h values of F1 hybrids of female resistant parent were higher than female susceptible parent, showing maternally enhanced dominance of Cry1Ac resistance. The progeny of F2 crosses, backcrosses of F1 hybrid with resistant BH-R parent did not differ significantly in respect of mortality response with resistant parent except for backcross with female BH-R and male of F1 (BH-R × VA-S) cross, suggesting dominant inheritance of Cry1Ac resistance. Evaluation of some biological attributes showed that larval and pupal periods of progenies of reciprocal F1 crosses, backcrosses and F2 crosses were either at par with resistant parent or lower than susceptible parent on treated diet (0.01 μg/g). The susceptible strain performed better in terms of pupation and adult formation than the resistant strain on untreated diet. In many backcrosses and F2 crosses, Cry1Ac resistance favored emergence of more females than males on untreated diet. The normal larval period and the body weight (normal larval growth) were the dominant traits associated with susceptible strain as contrast to longer larval period and the lower body weight (slow growth) associated with resistance trait. Further, inheritance of larval period in F2 and backcross progeny suggested existence of a major resistant gene or a set of tightly linked loci associated with Cry1Ac sensitivity. 相似文献
10.
Menkir A Olowolafe MO Ingelbrecht I Fawole I Badu-Apraku B Vroh BI 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,113(1):90-99
Introduction of exotic maize (Zea mays L.) into adapted tropical germplasm may enhance genetic variability and lead to greater progress from selection. The first objective of this study was to determine if yellow endosperm lines derived from adapted × exotic backcrosses contain exotic alleles that are superior to the recurrent adapted parental line for yield and other agronomic traits in tropical environments. Thirteen exotic yellow maize inbred lines were crossed to an adapted orange line (KUSR) and the F1s were backcrossed to KUSR to generate the first backcrosses. Fifty BC1F4 lines derived from these backcrosses and the recurrent parent were crossed to a common inbred tester (L4001) to form testcrosses, which were evaluated at eight environments in Nigeria. Testcrosses of the BC-derived lines differed significantly for grain yield and other agronomic traits. Only two testcrosses yielded significantly less than L4001 × KUSR, with the best 15 testcrosses producing between 289 and 1,056 kg/ha more grain yield than L4001 × KUSR. The best testcrosses were similar to or better than L4001 × KUSR for other agronomic traits. The second objective of this study was to assess the extent of genetic diversity present among the BC-derived lines. We genotyped 46 BC-derived lines including KUSR and L4001 with 10 AFLP primer pairs and found 491 polymorphic fragments. The average allelic diversity of the lines was 0.30 ± 0.01. The genetic distance of each BC-derived line from KUSR ranged between 0.49 and 0.91. The average genetic distance for all pairs of the BC-derived lines was 0.68 ± 0.004, varying from 0.34 to 0.92. The increased grain yield and genetic diversity observed in these studies provide evidence that exotic germplasm can contribute new alleles to expand the genetic base of tropical maize and develop high-yielding hybrids. 相似文献
11.
Todd Hatfield 《Environmental Biology of Fishes》1997,49(1):63-69
This paper describes patterns of developmental asymmetry in a limnetic-benthic stickleback species pair from Paxton Lake, British Columbia. Three gill raker characters and one armor character were compared among full-sib parental crosses and their hybrids (F1, F2 and backcrosses). All crosses displayed asymmetry, but no differences in mean or fluctuating asymmetry were detected among laboratory-reared crosses. When wild-caught limnetics and benthics were included in the analyses significant differences in FA among groups were detected in gill raker length and plate number. The effect appears to be solely due to wild-caught benthics, though the reasons for their greater asymmetry are unknown. The patterns in laboratory-reared crosses suggest that asymmetry is unlikely to promote reproductive isolation between the parental species. 相似文献
12.
David Scott 《Evolution; international journal of organic evolution》1994,48(1):112-121
Comparisons between the Canton-S and Tai-Y strains of Drosophila melanogaster (both wild type) revealed variation in female mate discrimination based on chemical courtship signals present as hydrocarbons on the male cuticle. Mating tests indicated that 7-tricosene, which is the primary hydrocarbon on the Canton-S male cuticle but is nearly absent from Tai-Y, was a significant component of the signal. The discrimination was asymmetrical in that Canton-S females clearly distinguished between the two types of males in no-choice tests, but Tai-Y females did not. F1 females expressed an intermediate ability to discriminate, and female progeny of backcrosses expressed a mating phenotype very similar to that of the parental strain to which the backcross was made. Analysis of independent effects from the X and both major autosomes indicated that the discrimination is controlled by gene(s) on chromosome 3. 相似文献
13.
J. E. BRADSHAW DOROTHY J. GEMMELL CYNTHIA J. WILLIAMSON 《The Annals of applied biology》1989,114(2):359-366
A complete diallel set of crosses, including selfs, was produced from 11 inbred lines of swedes and assessed for adult plant resistance to powdery mildew in a replicated field trial. The plants were inoculated with powdery mildew spores on 23 July 1987. Traces of mildew were visible on 3 August. By 14 September the most susceptible inbred line had 95% of its leaf area infected, whereas the three most resistant lines derived from cvs Bangholm Dima (two lines) and Bangholm Magres (one line) had only 5%. Resistance was controlled by partially recessive genes. There was no evidence of maternal effects. The implications for breeding inbred and F1 hybrid swede cultivars are discussed. 相似文献
14.
T. P. Bogyo J. W. Paulis J. A. Bietz J. S. C. Smith 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,87(1-2):33-37
A genetic model developed by Bogyo et al. (1988) for quantitatively inherited triploid endosperm characters (an extension of the well-known Mather-Jinks model) is not well-suited for estimating epistatic interaction effects because it requires the assumption that, in segregating loci, all alleles positively affecting a particular character are in one of the inbred parental lines. To better explain zein inheritance in maize, a new model was developed not relying on this assumption. This model was tested by quantitative analysis of A/B zeins, the predominant prolamin storage proteins of maize, using reversed phase high-performance liquid chromatography of two inbred lines, their reciprocal F1 crosses, the F2 generation, backcrosses, and reciprocal backcrosses to both parent lines. The model required epistatic components to be included for an excellent fit for most protein peaks.Scientific Paper No. 3 Program in Statistics, Washington State University, Pullman WA 99164. The mention of firm names or trade products does not imply that they are endorsed or recommended by the US Department of Agriculture over other firms or similar products not mentioned 相似文献
15.
H. A. Eagles 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1982,62(1):81-87
Summary The improvement of rate of seedling emergence and early seedling growth of maize (Zea mays L.) under cool conditions has been an objective of breeding programs in cool regions for many years. To study inheritance of emergence time, and to determine if differences in emergence time were due to differences in seedling growth, F1, F2 and backcross generations of a diallel cross of two rapidly emerging lines from CIMMYT Pool 5, 5-113 and 5-154, and two elite Corn Belt Dent lines, A619 and A632, were grown in controlled environment rooms at low temperatures.The lines from Pool 5 emerged significantly faster than A619 and A632 over a range of low temperature conditions. This difference occurred both when the lines themselves were tested and when the lines were tested as male and female parents in crosses. The Pool 5 lines converted a higher proportion of their original seed to new root and shoot tissue than did A619 and A632, indicating that they had a faster seedling growth rate. Primarily this was due to a faster loss of seed reserve, rather than a more efficient conversion process.A significant difference occurred between A619 and A632 for emergence time, but this was not due to a difference in seedling growth rate.Reciprocal differences occurred only in the F1 generation in crosses involving A619, and then marked effects could be attributed to the male parent. Reciprocal differences tended to disappear in the F2. This suggested that the genotype of the embryo and endosperm was of much greater importance than the genotype of the maternal parent in determining differences of time to emergence and seedling growth.Mid-parent heterosis occurred for time to emergence and seed loss, a measure of mean rate of utilization of seed reserve, in all crosses. High parent heterosis occurred in several crosses for these traits. High parent heterosis occurred in all crosses for efficiency of utilization of seed reserve.A generation means analysis indicated that both additive and dominance effects were present for rate of seedling growth in crosses between A632 and the Pool 5 lines. 相似文献
16.
Zhong Li Shihua Duan Jin Kong Shaoqing Li Yangsheng Li Yingguo Zhu 《Plant Cell, Tissue and Organ Culture》2007,89(2-3):237-245
Being the crucial step for rice transgenic manipulation, callus culture from mature seeds is severely restricted by browning
of induced calli, especially in the case of indica (Oryza Sativa L.) rice. Once this browning occurs, the callus will die and no embryonic calli can be obtained for regeneration. Here we
report an induction procedure that overcomes callus browning was found. To clarify the inheritance pattern of callus browning,
two reciprocal crosses F2 and two backcrosses BC1 were made between indica cultivar inbred lines 93-11 and YueTaiB (YTB) which produced normal and browning respectively in
the same induction medium. The ratio of browning to normal in the reciprocal F2 and backcross (BC1) populations tested was approximately 1:3 and 1:1, respectively, these results indicate that callus browning is controlled
by one single chromosomal locus which is tentatively named Ic1 (Induced callus 1). The genetic mapping of this locus was carried out using microsatellite markers (SSR) in a 216 extremely browning F2 seed callus. The analysis of genetic linkage indicated that one single locus that mapped to chromosome 1 was correlated to
callus browning, and the closest marker in this study was mapped within 1.9 cM from the target locus. 相似文献
17.
H. Ceballos S. Pandey L. Narro J. C. Perez-Velázquez 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(5):662-668
Acid soils severely reduce maize (Zea mays L.) yield in the tropics. Breeding for tolerance to soil acidity provides a permanent, environmentally friendly, and inexpensive solution to the problem. This study was carried out to determine the relative importance of additive, dominant, and epistatic effects on maize grain-yields in different tropical genotypes. Divergent selection in three populations (SA4, SA5, and SA7) provided inbred lines tolerant or sensitive to acid soils. The tolerant and sensitive lines from each population were used to obtain the F1, F2, F3, back-crosses, second back-crosses, and selfed back-cross generations. In addition, the tolerant lines from SA4 and SA5 were crossed with a sensitive line from the Tuxpeño Sequía population, from which the same generations were also derived. All generations from each of the five sets of crosses were evaluated in three acid-soil environments and one non-acid-soil environment. A generation-mean analysis was performed on each set for yield. The sequential sum of squares associated with additive, dominance, and digenic epistatic effects were used to estimate the relative importance of each genetic effect. Epistasis was not important in any set in the non-acid-soil environment, with dominance accounting for 80.76% of the total variation among generation means across sets. In acid-soil environments, epistasis was more important. The relative importance of digenic epistasis was greater in those evaluations with large experimental errors. The tolerant line from population SA5 was prone to severe root lodging, suggesting a very poor root system. Apparently, the tolerance to soil acidity in this line is not associated with a large root system. 相似文献
18.
D. P. Singh 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1980,57(5):233-235
Summary The inheritance of resistance to mungbean yellow mosaic virus (MYMV) was studied in blackgram (Vigna mungo (L.) Hepper). The highly resistant donors Pant U-84 and UPU-2 and a highly susceptible line, UL-2, their F1's, F2's and backcrosses were grown with spreader located every 5 to 6 rows. The resistance was found to be digenic and recessive in all the crosses and free from cytoplasmic effect. 相似文献
19.
To what extent is adaptive evolution over short timescales repeatable? To address this question, we studied the performance of crosses between replicate Drosophila melanogaster lines previously subject to selection for improved learning response in the context of oviposition substrate choice. Of the 10 pairwise F1 crosses among the five selection lines, four performed in the original learning assay similarly to the parental lines, whereas the remaining six showed learning scores significantly below the average of the parental lines. In particular, four F1 crosses (three involving the same line) showed no detectable learning, on a par with unselected control lines. This indicates that the response to selection in some lines involved allelic substitutions at different loci. Additional assays of crosses between two selection lines indicated that the loss of performance in hybrids generalized to another type of learning assay, and held for both short‐ and long‐term memory. Joint analysis of first‐ and second‐generation crosses between these two lines supported the hypothesis that the response to selection in these different lines was based on the spread of recessive alleles at different loci. These results show that the evolutionary trajectories of populations of the same origin subject to uniform selection may sometimes diverge over very short evolutionary timescales. 相似文献
20.
M. A. Akhmedov 《Russian Journal of Genetics》2010,46(8):1016-1018
In studies of the hybrid combination ((F4 Khar’kovskaya 46 × Triticum dicoccum) × Khar’kovskaya 46), a short-stemmed line, whose progeny exhibited traits of hybrid dwarfism, segregated with a frequency
close to 1: 15. Analysis of this line in F3 and hybrids from crosses of the short-stemmed line from this combination with the long-stemmed accession T. turgidum L. (c-38097) showed that the stem size variability curves of the both lines have two peaks. Since these results cannot be
explained by complementary interaction of D genes, hybrid dwarfism is probably controlled by pleiotropic action of two genes that have multiple pleiotropic effect on
the D
2
D
2
D
3
D
3
genes. Two or three rounds of selection performed on the progeny of plants higher than 80–100 cm produces stable lines without
hybrid dwarfism traits, i.e., the pleiotropic effect disappears. 相似文献