共查询到20条相似文献,搜索用时 15 毫秒
1.
R. E. Voorrips M. C. Jongerius H. J. Kanne 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):75-82
A genetic map covering 615 cM in 12 linkage groups was assembled based on 92 RFLP and AFLP markers segregating in a population
of 107 doubled haploid lines (DH lines) of Brassica oleracea. The DH-line population was obtained through microspore culture from the of two homozygous parents: DH-line Bi derived from the cabbage landrace Bindsachsener, and DH-line Gr from broccoli cv ‘Greenia’.
Sixty-five percent of the loci, and in some cases complete linkage groups, displayed distorted segregation ratios, a frequency
much higher than that observed in populations of the same species. DH-line Bi was resistant to clubroot, which is caused by a Dutch field isolate of Plasmodiophora brassicae. Resistance in the DH-line population was determined in two ways: by assigning symptom grades to each plant, and by measuring
the fresh weights of the healthy and affected parts of the root system of each plant. Using a multiple QTL mapping approach
to analyze the fresh weight data, we found two loci for clubroot resistance; these were designated pb-3 and pb-4. The additive effects of these loci were responsible for 68% of the difference between the parents and for 60% of the genetic
variance among DH-line means. Also, indications for the presence of two additional, minor QTLs were found. Analysis of symptom
grades revealed the two QTLs pb-3 and pb-4, as well as one of the two minor QTLs indicated by analysis of the fresh weight data.
Received: 29 April 1996 / Accepted: 10 May 1996 相似文献
2.
Comparative mapping of QTLs for agronomic traits of rice across environments by using a doubled-haploid population 总被引:11,自引:0,他引:11
Chaofu Lu Lishuuang Shen Ping He Ying Chen Lihuang Zhu Zhenbo Tan Yunbi Xu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):145-150
We report here the RFLP mapping of quantitative trait loci (QTLs) which affect some important agronomic traits in cultivated
rice. An anther culture-derived doubled-haploid (DH) population was established from a cross between indica and japonica rice
varieties. A molecular linkage map comprising 137 markers was constructed based on this population which covered the rice
genome at intervals of 14.8 cM on average. The linkage map was used to locate QTLs for such important agronomic traits as
heading date, plant height, number of spikelets per panicle, number of grains per panicle, 1 000-grain weight and the percentage
of seed set, by interval mapping. Evidence of genotype-by-environment interaction was found by comparing QTL maps of the same
population grown in three diverse environments. A total of 22 QTLs for six agronomic traits was detected which were significant
in at least one environment, but only seven were significant in all three environments; seven were significant in two environments
and eight could only be detected in a single environment. However, QTLs-by-environment interaction was trait dependent. QTLs
for spikelets and grains per panicle were common across environments while traits like heading date and plant height were
more sensitive to environment.
Received: 22 February 1996 / Accepted: 10 May 1996 相似文献
3.
Gliadin polymorphism in wild and cultivated einkorn wheats 总被引:4,自引:0,他引:4
M. Ciaffi L. Dominici D. Lafiandra 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):68-74
To study the relationships between different species of the Einkorn group, 408 accessions of Triticum monococcum, T. boeoticum, T. boeoticum ssp. thauodar and T. urartu were analyzed electrophoretically for their protein composition at the Gli-1 and Gli-2 loci. In all the species the range of allelic variation at the loci examined is remarkable. The gliadin patterns of T. monococcum and T. boeoticum were very similar to one another but differed substantially from those of T. urartu. Several accessions of T. boeoticum and T. monococcum were shown to share the same alleles at the Gli-1 and Gli-2 loci, confirming the recent nomenclature that considers these wheats as different subspecies of the same species, T. monococcum. The gliadin composition of T. urartu resembled that of the A genome of polyploid wheats more than did T. boeoticum or T. monococcum, supporting the hypothesis that T. urartu, rather than T. boeoticum, is the donor of the A genome in cultivated wheats. Because of their high degree of polymorphism the gliadin markers may
help in selecting breeding parents from diploid wheat germ plasm collections and can be used both to search for valuable genes
linked to the gliadin-coding loci and to monitor the transfer of alien genes into cultivated polyploid wheats.
Received: 8 July 1996 / Accepted: 12 July 1996 相似文献
4.
Rongling Wu 《Evolution; international journal of organic evolution》1998,52(4):967-977
The molecular genetic mechanisms for phenotypic plasticity across heterogeneous macro- and microenvironments were examined using the Populus genomic map constructed by DNA-based markers. Three hypotheses have been suggested to explain genetic variation in phenotypic response to varying environments (i.e., reaction norm): Lerner's homeostasis, allelic sensitivity, and gene regulation. The homeostasis hypothesis, which predicts that heterozygotes are less sensitive to the environment than homozygotes, was supported for phenotypic plasticity to unpredictable environments (microenvironmental plasticity) at the whole-genome level, but for phenotypic plasticity to predictable environments (macroenvironmental plasticity) the hypothesis was supported only at functioning quantitative trait loci (QTLs). For all growth traits studied, gene regulation was suggested to play a prevailing role in determining the norms of reaction to environments. Indirect evidence for gene regulation is that there tend to be more QTLs with larger effects on the phenotype in optimal growing conditions than suboptimal growing conditions because the expression of these QTLs identified is mediated by regulatory genes. Direct evidence for gene regulation is the identification of some loci that differ from QTLs for trait values within environments and exert an environmentally dependent control over structural gene expression. In this study, fewer environmentally sensitive QTLs were detected that display unparalleled allelic effects across environments. For stem height, there were more regulatory loci and more structural loci (whose expression is determined by gene regulation) affecting phenotypic plasticity than for basal area. It was found that microenvironmental plasticity was likely controlled by different genetic systems than those for macroenvironmental plasticity. 相似文献
5.
R. Bernardo 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(3-4):551-556
Marker-based assortative mating (MAM) – the mating of individuals that have similar genotypes at random marker loci – can
increase selection response for a single trait by 3–8% over random mating (RM). Genetic gain is usually desired for multiple
traits rather than for a single trait. My objectives in this study were to (1) compare MAM, phenotypic assortative mating
(PAM), and RM of selected individuals for improving two traits and (2) determine when MAM will be most useful for improving
two traits. I simulated 20 generations of selecting 32 out of 200 individuals in an F2 population. The individuals were selected based on an index (SI) of two traits and were intermated by MAM, PAM, or RM. I
studied eight genetic models that differed in three contrasts: (1) weight, number of quantitative trait loci (QTL), and heritability
(h
2) for each trait; (2) linkage of QTL for each trait; and (3) trait means of the inbred parents of the F2. For SI and the two component traits, MAM increased short-term selection response by 5–8% in six out of the eight genetic
models. The MAM procedure was least effective in two genetic models, wherein the QTL for one trait were unlinked to the QTL
for the other trait and the parents of the F2 had divergent means for each trait. The loss of QTL heterozygosity was much greater with MAM than with PAM or RM. Consequently,
the advantage of MAM over RM dissipated after 5–7 generations. Differences were small between selection responses with PAM
and RM. The MAM procedure can enhance short-term selection response for two traits when selection is not stringent, h
2 is low, and the means of the parents of the F2 are equal for each trait.
Received: 10 June 1998 / Accepted: 5 August 1998 相似文献
6.
M. J. Iqbal N. Aziz N. A. Saeed Y. Zafar K. A. Malik 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):139-144
Random amplified polymorphic DNA (RAPD) analysis was used to evaluate the genetic diversity of elite commercial cotton varieties.
Twenty two varieties belonging to Gossypium hirsutum L. and one to G. arboreum L. were analyzed with 50 random decamer primers using the polymerase chain reaction (PCR). Forty nine primers detected polymorphism
in all 23 cotton varieties, while one produced monomorphic amplification profiles. A total of 349 bands were amplified, 89.1%
of which were polymorphic. Cluster analysis by the unweighted pair group method of arithmetic means (UPGMA) showed that 17
varieties can be placed in two groups with a similarity ranging from 81.51% to 93.41%. G. hirsutum L. varieties S-12, V3 and MNH-93 showed a similarity of 78.12, 74.46 and 69.56% respectively with rest of the varieties. One
variety, CIM-1100, showed 57.02% similarity and was quite distinct. The diploid cotton G. arboreum L. var. Ravi was also very distinct from rest of its tetraploid counterparts and showed only 55.7% similarity. The analysis
revealed that the intervarietal genetic relationships of several varieties is related to their center of origin. As expected,
most of the varieties have a narrow genetic base. The results obtained can be used for the selection of possible parents to
generate a mapping population. The results also reveal the genetic relationship of elite commercial cotton varieties with
some standard “Coker” varieties and the diploid G. arboreum L. var. Ravi (old world cotton).
Received: 12 July 1996 / Accepted: 26 July 1996 相似文献
7.
Levels of genetic diversity at different stages of the domestication cycle of interior spruce in British Columbia 总被引:3,自引:0,他引:3
M. U. Stoehr Y. A. El-Kassaby 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):83-90
Concerns over the reductionist nature of the domestication of forest-tree species focus on the possibility of potential genetic
erosion during this process. To address these concerns, genetic diversity assessments in a breeding zone the Province of British
Columbia “interior” spruce (Picea glauca×engelmanni) program was conducted using allozyme markers. Genetic-variation comparisons were made between natural and production (seed
orchard) populations as well as seed and seedling crops produced from the same breeding zone’s seed orchard. The natural population
sample consisted of a total of 360 trees representing three stands within each of three watersheds present in the Shuswap-Adams
low-elevation zone of interior British Columbia. Small amounts of genetic differentiation were observed among the nine natural
populations (4%) and this was attributable to extensive gene flow Consequently, the sum of these nine populations was considered as a baseline for the genetic variation present in the breeding
zone. The comparisons between the seed orchard and the breeding zone produced a similar percentage of polymorphic loci while the expected hetrozygosity (0.207 vs 0.210) and the average number of alleles per locus (2.7 vs 2.4) were slightly lower in the seed orchard. A total
of seven natural populations’ rare alleles were not present in the orchard population, while one allele was unique to the orchard. The %P increased to 70.6% in the seedlot, but dropped to the natural populations level (64.7%) in the plantation. The observed increase
in %P was a result of pollen contamination in the orchard. It is suspected that the reduction in the plantation was caused by an
unintentional selection in the nursery. Simulated roguing in the orchard did not drastically reduce even if up to 50% of the orchard’s clones were rogued. However, roguing was associated with a reduction in the average number
of alleles per locus (i.e., sampling effect).
Received: 2 January 1996 / Accepted: 24 May 1996 相似文献
8.
We are developing budding yeast, Saccharomyces cerevisiae, as a genetic system for the study of tolerance to the trivalent aluminum cation (Al3+). We have isolated eight mutants that are more sensitive to Al3+ than the wild type. Each mutant represented a different complementation group. A number of the mutants were pleiotropic,
and showed defects in other stress responses, changes in tolerance to other metal cations, or abnormal morphology. Two mutants
also showed increased dependence on supplemental Mg2+ and Ca2+. One mutant with a relatively specific sensitivity to Al3+ was chosen for molecular complementation. Normal Al3+ tolerance was restored by expression of the MAP kinase gene SLT2. Strains carrying deletions of the SLT2 gene, or of the gene for the corresponding MAP kinase–kinase SLK1, showed sensitivity to Al3+. These results indicate that the SLT2 MAP kinase signal transduction pathway is required for yeast to sense and respond to Al3+ stress.
Received: 17 April 1996 / Accepted: 21 October 1996 相似文献
9.
RFLP mapping of resistance to chlorosis induction by Pyrenophora tritici-repentis in wheat 总被引:2,自引:0,他引:2
J. D. Faris J. A. Anderson L. J. Francl J. G. Jordahl 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):98-103
Tan spot, caused by Pyrenophora tritici-repentis, is an economically important disease in major wheat production areas. The fungus can produce two genetically distinct symptoms
on leaves of susceptible wheat genotypes: tan necrosis (nec) and extensive chlorosis (chl). Our objectives were to determine
the number of genes conditioning resistance to tan spot in a population of wheat recombinant inbred lines, and map the chromosomal
location of the resistance genes using RFLPs. Conidia produced by the P. tritici-repentis isolate Pti2 (nec+chl+) were used to inoculate seedlings of 135 recombinant inbred lines derived from the cross of the synthetic
hexaploid wheat W-7984 with Opata 85. A subset of the population was inoculated with conidia produced by the isolates D308
(nec−chl+) and 86-124 (nec+chl−). Inoculated seedlings were rated on a scale of 1 to 5 based on lesion type. Necrosis-inducing
culture filtrate produced by the isolate 86-124 was also used to screen the entire population. A map consisting of 532 markers
was employed to identify significant associations between marker loci and tan spot resistance. The entire population was insensitive
to culture filtrate produced by the isolate 86-124, and the entire subset was resistant to conidial inoculation of the same
isolate. The population segregated for reaction to isolates D308 and Pti2, indicating that this population segregates for
resistance to extensive chlorosis only, and not to tan necrosis. RFLP analysis indicated the presence of a gene with a major
effect in 1AS, a gene with a minor effect in 4AL, and an interaction between the 1AS gene and a gene in 2DL. Together, these
loci explained 49.0% of the variation in this population for resistance to tan spot produced by the isolate Pti2. Two regions
one in 1BL and one in 3BL, were significantly associated with resistance to extensive chlorosis, but were not significant
in the multiple regression model. It should be feasible to introgress these resistance loci into adapted genetic backgrounds
by using a marker-assisted selection scheme.
Received: 30 March 1996 / Accepted: 31 May 1996 相似文献
10.
The ability of a single genotype to generate different phenotypes in disparate environments is termed phenotypic plasticity, which reflects the interaction of genotype and environment on developmental processes. However, there is controversy over the definition of plasticity genes. The gene regulation model states that plasticity loci influence trait changes between environments without altering the means within a given environment. Alternatively, the allelic sensitivity model argues that plasticity evolves due to selection of phenotypic values expressed within particular environments; hence plasticity must be controlled by loci expressed within these environments. To identify genetic loci controlling phenotypic plasticity and address this controversy, we analyzed the plasticity of glucosinolate accumulation under methyl jasmonate (MeJa) treatment in Arabidopsis thaliana. We found genetic variation influencing multiple MeJa signal transduction pathways. Analysis of MeJa responses in the Landsberg erecta x Columbia recombinant inbred lines identified a number of quantitative trait loci (QTL) that regulate plastic MeJa responses. All significant plasticity QTL also impacted the mean trait value in at least one of the two "control" or "MeJa" environments, supporting the allelic sensitivity model. Additionally, we present an analysis of MeJa and salicylic acid cross-talk in glucosinolate regulation and describe the implications for glucosinolate physiology and functional understanding of Arabidopsis MeJa signal transduction. 相似文献
11.
M. Keller B. Keller G. Schachermayr M. Winzeler J. E. Schmid P. Stamp M. M. Messmer 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(6-7):903-912
Powdery mildew is one of the major diseases of wheat in regions with a maritime or semi-continental climate and can strongly
affect grain yield. The attempt to control powdery mildew with major resistance genes (Pm genes) has not provided a durable resistance. Breeding for quantitative resistance to powdery mildew is more promising, but
is difficult to select on a phenotypic basis. In this study, we mapped and characterised quantitative trait loci (QTLs) for
adult-plant powdery mildew resistance in a segregating population of 226 recombinant inbred lines derived from the cross of
the Swiss wheat variety Forno with the Swiss spelt variety Oberkulmer. Forno possibly contains the Pm5 gene and showed good adult-plant resistance in the field. Oberkulmer does not have any known Pm gene and showed a moderate susceptible reaction. Powdery mildew resistance was assessed in field trials at two locations
in 1995 and at three locations in 1996. The high heritability (h2=0.97) for powdery mildew resistance suggests that the environmental influence did not affect the resistance phenotype to
a great extent. QTL analysis was based on a genetic map containing 182 loci with 23 linkage groups (2469 cM). With the method
of composite interval mapping 18 QTLs for powdery mildew resistance were detected, explaining 77% of the phenotypic variance
in a simultaneous fit. Two QTLs with major effects were consistent over all five environments. One of them corresponds to
the Pm5 locus derived from Forno on chromosome 7B. The other QTL on 5A, was derived from the spelt variety Oberkulmer and did not
correspond to any known Pm gene. In addition, five QTLs were consistent over three environments, and six QTLs over two environments. The QTL at the
Pm5 locus showed a large effect, although virulent races for Pm5 were present in the mixture of isolates. Molecular markers linked with QTLs for adult-plant resistance offer the possibility
of simultaneous marker-assisted selection for major and minor genes.
Received: 22 September 1998 / Accepted: 26 October 1998 相似文献
12.
Mapping of the Rf-3 nuclear fertility-restoring gene for WA cytoplasmic male sterility in rice using RAPD and RFLP markers 总被引:24,自引:0,他引:24
G. Zhang Y. Lu T. S. Bharaj S. S. Virmani N. Huang 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):27-33
The cytoplasmic male sterility (CMS) of wild-abortive (WA) cytoplasm has been widely used for breeding hybrid rice. Two restorer
genes for the CMS have been found by traditional genetic analysis. To tag the restorer genes we used a set of near-isogenic
lines (NILs) of Zhenshan 97 carrying different genotypes for fertility restoration from IR24, to perform RAPD analysis. From
the survey of 720 random primers, six RAPD markers were identified to be associated with Rf-3. Three of these OPK05-800, OPU10-1100 and OPW01-350, were mapped on chromosome 1. Two populations from the crosses between Zhenshan 97 A and a near-isogenic restorer line ZSR21 and between Zhenshan 97 A and
IR24 were used for mapping Rf-3. The three RAPD markers and three RFLP markers, RG532, RG140 and RG458, were found to be closely linked to Rf-3 in the two populations. The same location of Rf-3 was also found in a population from the cross of IR58025 A//IR36/IR58025 B. At the RG532 locus, different alleles were found between two CMS
lines, Zhenshan 97 A and IR58025 A, and between two restorer lines, IR24 and IR36. The use of these molecular markers closely
linked to Rf-3 in facilitating the development of hybrid rice is discussed.
Received: 3 January 1996 / Accepted: 17 May 1996 相似文献
13.
M. A. R. Mian E. R. Shipe J. Alvernaz J. D. Mueller D. A. Ashley H. R. Boerma 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(8):971-974
Soybean, Glycine max (L.) Merr., genotypes are known to differ in chlorimuron ethyl sensitivity (CS). Earlier we have reported two putatively
independent marker loci linked to two quantitative trait loci (QTLs) controlling CS in a soybean population derived from a
cross of PI97100 (sensitive to chlorimuron ethyl) and ‘Coker 237’ (tolerant to chlorimuron ethyl). The objective of the present
study was to quantify the association of the two marker loci with seed yield and related traits in this soybean population
following application of chlorimuron ethyl. Phenotypic data were collected for 111 F2-derived lines of the cross grown in replicated plots at Athens, G.A., in 1994 and 1995, and at Blackville, S.C., in 1995.
The two CS marker loci explained as much as 50% of the genetic variation in seed yield and seed number m-2, but had no association with seed weight, plant height, lodging, seed protein, and seed oil. There were no epistatic interactions
between the two marker loci for any of the traits. The marker locus (cr168-1 on USDA linkage group E) linked to the major
CS QTL explained between 13 and 23% of the variation in seed yield. The Coker 237 allele at this locus was associated with
decreased CS and increased seed yield. The marker locus (Blt015-2 on an unknown linkage group) linked to the minor CS QTL
accounted for a maximum of 11% of the variation in seed yield. The Coker 237 allele at this locus was associated with an increase
in CS and a decrease in seed yield. The association of the two marker loci with seed number m-2 strongly resembled their association with seed yield. Seed yield had a strong positive correlation (r=0.74 – 0.94) with seed number m-2, and the effect of chlorimuron ethyl on seed yield was due mainly to its effect on seed number m-2 rather than seed weight.
Received: 6 August 1996 / Accepted: 28 February 1997 相似文献
14.
Genetic variance, coefficient of parentage, and genetic distance of six soybean populations 总被引:4,自引:0,他引:4
T. Helms G. Vallad P. McClean J. Orf 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):20-26
Plant breeders would like to predict which biparental populations will have the largest genetic variance. If the population
genetic variance could be predicted using coefficient of parentage or genetic distance estimates based on molecular marker
data, breeders could choose parents that produced segregating populations with a large genetic variance. Three biparental
soybean {Glycine max (L.) Merr.} populations were developed by crossing parents that were closely related, based on pedigree relationships. Three
additional biparental populations were developed by crossing parents that were assumed to be unrelated. The genetic variance
of each population was estimated for yield, lodging, physiological maturity, and plant height. Coefficient of parentage was
calculated for each pair of parents used to develop the segregating populations. Genetic distance was determined, based on
the number of random amplified polymorphic markers (RAPD) that were polymorphic for each pair of parents. Genetic distance
was not associated with the coefficient of parentage or the magnitude of the genetic variance. The genetic variance pooled
across the three closely related populations was smaller than the genetic variance pooled across the three populations derived
from crossing unrelated parents for all four traits that were evaluated.
Received: 24 April 1996 / Accepted: 17 May 1996 相似文献
15.
C. M. Marques J. Vasquez-Kool V. J. Carocha J. G. Ferreira D. M. O’Malley B.-H. Liu R. Sederoff 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(6):936-946
We have detected quantitative trait loci (QTLs) affecting vegetative propagation traits in Eucalyptus tereticornis and Eucalyptus globulus. Using amplified fragment length polymorphism (AFLP) genetic linkage maps, the inheritance of 199 markers was assessed in
94 F1 individuals with extreme adventitious rooting response, and in 221 randomly chosen F1 individuals. Phenotypes were scored in 1995 and 1996. QTL analyses were performed using chi-square tests (χ2), single-marker analysis (SMA), interval mapping (IM) and composite interval mapping (CIM). All approaches yielded similar
QTL detection results. Three QTLs are hypothesized for mortality (MORT=% dead cuttings), nine for adventitious rooting (ROOT,
RCT=% rooted cuttings relative to the surviving or total cuttings, respectively), four for petrification (PETR=% surviving
unrooted cuttings), one for sprouting ability (SPR=number of stump sprout cuttings harvested in 1995) and four for the stability
of adventitious rooting (STAB=absolute value of the difference ROOT95-ROOT96). All putative QTLs for MORT and PETR were located
on the E. tereticornis map, and for SPR and STAB on the E. globulus map. We found different QTLs for MORT, ROOT, RCT, SPR and STAB. Putative QTLs accounted for 2.6–17.0% of the phenotypic variance
of a trait (R2). Estimated standardized gene substitution effects varied between 0.13 and 0.49 phenotypic standard deviations (σp). These results indicate that the phenotypic variation in these traits has a meaningful genetic component and that stable
QTLs can be found in a family of reasonable size where no previous knowledge of the trait was available.
Received: 1 September 1998 / Accepted: 24 February 1999 相似文献
16.
A. van Tuinen M. Koornneef M. -M. Cordonnier-Pratt L. H. Pratt R. Verkerk P. Zabel 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):115-122
The map positions of five previously described phytochrome genes have been determined in tomato (Lycopersicon esculentum Mill.) The position of the yg-2 gene on chromosome 12 has been confirmed and the classical map revised. The position of the phytochrome A (phy A)-deficient
fri mutants has been refined by revising the classical map of chromosome 10. The position of the PhyA gene is indistinguishable from that of the fri locus. The putative phyB1-deficient tri mutants were mapped by classical and RFLP analysis to chromosome 1. The PhyB1 gene, as predicted, was located at the same position. Several mutants with the high pigment (hp) phenotype, which exaggerates phytochrome responses, have been reported. Allelism tests confirmed that the hp-2 mutant is not allelic to other previously described hp (proposed here to be called hp-1) mutants and a second stronger hp-2 allele (hp-2
j
) was identified. The hp-2 gene was mapped to the classical, as well as the RFLP, map of chromosome 1.
Received: 24 May 1996 / Accepted: 14 June 1996 相似文献
17.
G. Besnard Y. Griveau M. C. Quillet H. Serieys P. Lambert D. Vares A. Bervillé 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):131-138
A method based upon targetting of intro-gressed markers in a Phomopsis-resistant line (R) of cultivated sunflower, issuing
from a H. argophyllus cross was used to mark the Phomopsis resistance regions. Our study was based upon 203 families derived from a cross between an inbred line susceptible to Phomopsis (S1) and the introgressed resistant line (R).
Families were checked for Phomopsis resistance level in a design with replicated plots and natural infection was re-inforced
by pieces of contaminated stems. Thirty four primers were employed for RAPD analysis. Out of 102 polymorphic fragments between
(S1) and H. argophyllus, seven were still present in (R) suggesting that they marked introgressions of H. argophyllus into (R). The plants were scored for the presence or absence of 19 fragments obtained from five primers, and the relationships between
the presence/absence of fragments in plants and Phomopsis resistance/susceptiblity in the progenies was determined by using an analysis of variance. We found that at least two introgressed regions, as well as favourable
factors from sunflower, contributed to the level of Phomopsis resistance in cultivated sunflower.
Received: 28 June 1996 / Accepted: 5 July 1996 相似文献
18.
Recombination mapping of some chromosome 1A-, 1B-, 1D- and 6B-controlled gliadins and low-molecular-weight glutenin subunits in common wheat 总被引:2,自引:0,他引:2
E. V. Metakovsky G. Branlard V. M. Chernakov V. P. Upelniek R. Redaelli N. E. Pogna 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(6-7):788-795
Inheritance of low-molecular-weight glutenin subunits (LMW GS) and gliadins was studied in the segregating progeny from several
crosses between common wheat genotypes. The occurrence of a few recombinants in the F2 grains of the cross Skorospelka Uluchshennaya×Kharkovskaya 6 could be accounted for by assuming that the short arm of chromosome
1D contains two tightly linked loci each coding for at least one gliadin plus one C-type LMW GS. These loci were found to
recombine at a frequency of about 2%, and to be linked to the Glu-D3 locus coding for B-type LMW GS. Some proteins showing biochemical characteristics of D-type or C-type LMW GS were found to
be encoded by the Gli-B1 and Gli-B2 loci, respectively. Strongly stained B-type LMW GS in cvs Skorospelka Uluchshennaya and Richelle were assigned to the Glu-B3 locus, but recombination between this locus and Gli-B1 was not found. Analogously, in the cross Bezostaya 1×Anda, no recombination was found between Gli-A1 and Glu-A3, suggesting the maximum genetic distance between these loci to be 0.97% (P=0.05). A B-type LMW GS in cv Kharkovskaya 6 was assigned to the Glu-B2 locus, with about 25% recombination from the Gli-B1 locus. The present results suggested that alleles at Gli loci may relate to dough quality and serve as genetic markers of certain LMW GS affecting breadmaking quality.
Received: 9 July 1996/Accepted: 15 November 1996 相似文献
19.
Karen E. Parsons 《Oecologia》1997,110(4):461-471
Species with contrasting abilities for dispersal may adopt different strategies in response to wide ranges of environmental
conditions. These strategies were investigated here by comparisons of phenotypic differentiation and plasticity in the gastropods
Austrocochlea constricta and Bembicium vittatum, which coexist in a range of intertidal habitats on the Abrolhos Islands and Albany in Western Australia. They differ in
their potential for larval dispersal, A. constricta having a short mobile planktonic stage and B. vittatum developing directly from benthic eggs. Levels of among-population variation in shell shape and maximum size did not differ
between the species, or between locations subject to contrasting levels of gene flow in the case of A. constricta. Results of a common garden translocation experiment, coupled with those of previous breeding experiments, suggest that variation
in shape is predominantly genetically determined in B. vittatum, but plastic in A. constricta. Plasticity of shape in A. constricta was most pronounced at Albany, where previous data suggested the widest gene flow, and was greater than in B. vittatum at both locations. Change of shape in A. constricta subsequent to translocation was related to growth rate, a trait which was also more plastic in this species than in B. vittatum. The results agree with the notion that wide dispersal enhances physiological flexibility, while restricted dispersal promotes
local genetic adaptation, but disagree with the hypothesis that wide dispersal promotes phenotypic homogeneity.
Received: 31 May 1996 / Accepted: 30 September 1996 相似文献
20.
B. Hui Liu S. J. Knapp D. Birkes 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):8-19
Genetic correlations are frequently estimated from natural and experimental populations, yet many of the statistical properties of estimators
of are not known, and accurate methods have not been described for estimating the precision of estimates of Our objective was to assess the statistical properties of multivariate analysis of variance (MANOVA), restricted maximum
likelihood (REML), and maximum likelihood (ML) estimators of by simulating bivariate normal samples for the one-way balanced linear model. We estimated probabilities of non-positive
definite MANOVA estimates of genetic variance-covariance matrices and biases and variances of MANOVA, REML, and ML estimators
of and assessed the accuracy of parametric, jackknife, and bootstrap variance and confidence interval estimators for MANOVA estimates of were normally distributed. REML and ML estimates were normally distributed for but skewed for and 0.9. All of the estimators were biased. The MANOVA estimator was less biased than REML and ML estimators when heritability
(H), the number of genotypes (n), and the number of replications (r) were low. The biases were otherwise nearly equal for different estimators and could not be reduced by jackknifing or bootstrapping.
The variance of the MANOVA estimator was greater than the variance of the REML or ML estimator for most H, n, and r. Bootstrapping produced estimates of the variance of close to the known variance, especially for REML and ML. The observed coverages of the REML and ML bootstrap interval estimators
were consistently close to stated coverages, whereas the observed coverage of the MANOVA bootstrap interval estimator was
unsatisfactory for some H,
n, and r. The other interval estimators produced unsatisfactory coverages. REML and ML bootstrap interval estimates were narrower
than MANOVA bootstrap interval estimates for most H, and r.
Received: 6 July 1995 / Accepted: 8 March 1996 相似文献