共查询到20条相似文献,搜索用时 15 毫秒
1.
Several pollen-specific genes from different species have been isolated and characterized at the molecular level, but the precise role of most of them is unknown. Mutant analysis represents a direct approach to uncovering gene function, but the paucity of available mutants affecting pollen development and/or function and the poor characterization of the known mutants have so far limited the exploitation of this approach. Here we present the cytological characterization ofgametophytic male sterile-1 (gaMS-1), a maize mutant that we identified in a program of transposon insertion mutagenesis for the production of mutations in gametophytically acting genes involved in microsporogenesis.gaMS-1 is expressed during or immediately after the first microspore division and leads to the production of immature, nonfunctional pollen grains. The mutation appears to affect the events leading to the developmental switch that follows the first microspore mitosis. 相似文献
2.
In order to dissect the complex genetic system that controls pollen development, we have undertaken a program of transposon
insertion mutagenesis, with the purpose of producing mutations in gametophytically acting genes that are important for this
process. The present work reports the developmental cytology of one of the mutants isolated, gaMS-2 (gametophytic male sterile-2). A peculiar feature of the mutant grains was lack of differentiation between the vegetative and the generative nuclei, leading
to alteration in number, conformation and placement of nuclei. At anthesis, the grains carrying the mutant allele are about
40% of the normal grain size, contain a very reduced amount of starch and exhibit various nuclear abnormalities.
Received: 31 May 1996 / Revision accepted: 26 August 1996 相似文献
3.
Linkage mapping of maize and barley myo-inositol 1-phosphate synthase DNA sequences: correspondence with a low phytic acid mutation 总被引:6,自引:0,他引:6
S. R. Larson V. Raboy 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(1-2):27-36
We sequenced and genetically mapped the myo-inositol 1-phosphate synthase (MIPS) genes of maize (Zea mays L.) and barley (Hordeum vulgare L). Our objective was to determine whether the genetic map positions of these MIPS loci correspond with the location of the
low phtyic acid 1 (lpa1) mutations that were previously identified in maize and barley. Seven MIPS-homologous sequences were mapped to positions
on maize chromosomes 1S, 4L, 5S, 6S, 8L, 9S and 9L, and a similar number of divergent MIPS sequences were amplified from maize.
To the extent that we can compare across different genetic mapping populations, the position of the MIPS gene on maize chromosome
1S is identical to the location of the maize lpa1 mutation. However, only one MIPS sequence was identified in barley and this gene was mapped to a locus on chromosome 4H that
is separate from the barley lpa1 mutation on chromosome 2H. Although several RFLP markers linked to the barley MIPS gene on chromosome 4H also detect loci
near barley lpa1 on chromosome 2H, our experiments failed to reveal a second MIPS gene that could be associated with the barley lpa1 mutation. Therefore, genetic mapping results from this study support the MIPS candidate-gene hypothesis for maize lpa1, but do not support the MIPS candidate-gene-hypothesis for barley lpa1. These opposing results contradict the hypothesis that maize lpa1 and barley lpa1 are mutations of orthologous genes, which is suggested by the similar biochemical phenotypes of these mutants. Yet, comparisons
of RFLP mapping studies show loci that are homologous between maize chromosome 1S, barley chromosome 4H and barley chromosome
2H, including regions flanking the respective MIPS and/or lpa1 loci. This putative relationship, between the regions flanking the lpa1 mutations on maize 1S and barley 2H, also supports the assertion that these mutations are orthologous despite contradictory
results between our maize and barley candidate-gene experiments.
Received: 24 August 1998 / Accepted: 19 December 1998 相似文献
4.
We examined the effects of pollen competition (pollen load size) on sporophytic vigor and gametophytic performance in Cucurbita texana, a wild gourd, while controlling for alternative interpretations of the data. Under field conditions we compared the vigor
of progeny produced from large and small pollen loads and examined the in vitro performance of the pollen produced by the
progeny. We found that the progeny from large pollen loads germinated faster and had a greater reproductive output (male flowers
and fruits) than progeny produced from small pollen loads. In addition, we found that the pollen produced on plants derived
from large pollen loads grew faster in vitro than the pollen produced on plants derived from small pollen loads. These findings
indicate that pollen competition affects the performance of the resulting sporophytic generation and the microgametophytes
they produce.
Received: 26 January 1997 / Revision accepted: 25 June 1997 相似文献
5.
This study examines sporophytic and gametophytic vigor in wild and cultivated varieties of Cucurbita pepo L. and their hybrids in order to determine whether hybrid vigor extends to the microgametophyte generation. It also examines
the variation in sporophytic and gametophytic vigor to discern the non-genetic influences of pollen provisioning by the sporophyte
on pollen performance from the genetic influences of the microgametophyte’s own genotype on pollen performance. A cultivated
and a wild C. pepo and their F1 and the F2 generations were grown under field conditions and flower and fruit production were monitored over
one summer. We found that the four types of plants differed significantly in the number of male and female flowers and the
number of fruits they produced. The F1 plants produced significantly more male flowers and marginally more female flowers
and fruits than the parental lines. To estimate gametophytic vigor pollen was germinated in vitro and pollen tube length measured
after 30 min. We found that pollen tubes from the F1 plants had significantly greater growth than tubes from the parental
lines or the F2 generation, indicating that hybrid vigor extends to the microgametophytic generation. By partitioning the
variance of pollen tube growth into ’within’ and ’among’ plant components of variation, we were able to show that the genotype
of the microgametophyte influences pollen performance in vitro, but that expression of hybrid vigor in the microgametophyte
is likely to be due to an environmental effect related to provisioning of the pollen grains during development.
Received: 16 April 1998 / Revision accepted: 18 August 1998 相似文献
6.
7.
T. L. Kamps C. D. Chase 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(4):525-531
Cytoplasmic male sterility (CMS) is the maternally inherited inability to produce functional pollen. The Rf3 allele of the nuclear gene rf3 gametophytically restores male fertility to maize plants with the S-type of CMS. The rf3 locus is on the long arm of maize chromosome two (2L). Using 2L RFLPs and three-point mapping analysis we showed that the
rf3 locus is located an estimated 4.3 cM distal to the whp locus and 6.4 cM proximal to the bnl17.14 locus. This information was used in combination with RFLPs on two additional maize chromosomes to show that Rf3/rf3 CMS-S plants may aberrantly transmit the nonrestoring allele, rf3, through the male gametophyte.
Received: 30 September 1996/Accepted: 21 March 1997 相似文献
8.
The actin cytoskeletal organization and nuclear behavior of normal and indeterminate gametophyte1 (ig1) embryo sacs of maize were examined during fertilization. After pollination, during degeneration of one of the synergids
and before arrival of the pollen tube, the cytoskeletal elements undergo dramatic changes including formation of the actin
coronas at the chalazal end of the degenerating synergid and at the interface between the egg cell and central cell. The actin
coronas are present only for a limited period of time and their presence is coordinated with pollen tube arrival and fusion
of the gametes; they disappear before the zygote divides. This allows us to estimate the frequency of fertilized ovules along
the ear. Up to 88% of the ovules on an ear contain actin coronas in the embryo sacs when observed 16–19 h after pollination,
indicating the high frequency of fertilizing kernels along the ear at this stage. In the ig embryo sacs, two or more degenerated synergids containing actin coronas at their chalazal ends receive multiple pollen tubes
for gametic fusion and can consequently give rise to twin or polyembryos. These findings with the monocot maize are consistent
with previous reports on the dicots Plumbago and Nicotiana, suggesting that the formation of actin coronas in the embryo sac during fertilization is a universal phenomenon in angiosperms
and is part of a mechanism of interaction between gametic signaling and actin cytoskeleton behavior which appears to precisely
position and facilitate the access of male gametes to the egg cell and central cell for fusion.
Received: 15 May 1998 / Revision accepted: 17 August 1998 相似文献
9.
10.
11.
M. C. Schneerman W. S. Lee G. Doyle D. F. Weber 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(3-4):361-366
The centromere of maize chromosome 4 was previously localized to a 26-cM interval using molecular markers and B-A translocations.
The objective of the present study was to refine the placement of the centromere using secondary trisomics. Two independently
isolated secondary trisomics (having an isochromosome plus two normal homologs) for 4S were recovered. RFLP analysis of populations
segregating for them placed the centromere of chromosome 4 between bnl15.45 and bnl7.20, two RFLP loci that are 5.4-cM apart on the UMC map and 11.5-cM apart on the BNL map.
Received: 19 May 1997 / Accepted: 6 October 1997 相似文献
12.
QTL mapping of resistance to Sporisorium reiliana in maize 总被引:6,自引:0,他引:6
T. Lübberstedt X. C. Xia G. Tan X. Liu A. E. Melchinger 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(3-4):593-598
We mapped and characterized quantitative trait loci (QTL) for resistance to Sporisorium reiliana. A population of 220 F3 families produced from the cross of two European elite inbreds (D32, D145) was evaluated with two replications at a French
location with high natural incidence of S. reiliana and at a Chinese location employing artificial inoculation. The 220 F3 families were genotyped with 87 RFLP and seven SSR markers. Using composite interval mapping, we identified two different
sets of 3 and 8 QTL for the French and the Chinese locations explaining 13% and 44% of respectively. Individual QTL explained
up to 14% of σ^2
p. The 11 QTL mapped to eight maize chromosomes and displayed mostly additive or partial dominant gene action. Significant
digenic epistatic interactions were detected for one pair of these QTL. Only a few QTL for S. reiliana were in common with QTL for resistance to Ustilago maydis and Puccinia sorghi, identified at a German location for the same population. Consequently, in our materials resistance to these three fungal
pathogens of maize seems to be inherited independently.
Received: 14. December 1998 / Accepted: 30 January 1999 相似文献
13.
Molecular marker diversity among current and historical maize inbreds 总被引:25,自引:0,他引:25
H. Lu R. Bernardo 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(4):613-617
Advanced-cycle pedigree breeding has caused maize (Zea mays L.) inbreds to become more-elite but more-narrow genetically. Our objectives were to evaluate the genetic distance among
current and historical maize inbreds, and to estimate how much genetic diversity has been lost among current inbreds. We selected
eight maize inbreds (B14, B37, B73, B84, Mo17, C103, Oh43 and H99) that largely represented the genetic background of current
elite inbreds in the U.S. seed industry. A total of 32 other inbreds represented historical inbreds that were once important
in maize breeding. Cluster analysis of the inbreds, using data for 83 SSR marker loci, agreed well with pedigree information.
Inbreds from Iowa Stiff Stalk Synthetic (BSSS), Reid Yellow Dent, and Lancaster clustered into separate groups with only few
exceptions. The average number of alleles per locus was 4.9 among all 40 inbreds and 3.2 among the eight current inbreds.
The reduction in the number of alleles per locus was not solely due to sample size. The average genetic distance (D
ij
) was 0.65 among the eight current inbreds, 0.67 among the 32 historical inbreds, and 0.67 among all 40 inbreds. These differences
were statistically insignificant. We conclude that genetic diversity among current inbreds has been reduced at the gene level
but not at the population level. Hybrid breeding in maize maintained, rather than decreased, genetic diversity, at least during
the initial subdivision of inbreds into BSSS and non-BSSS heterotic groups. We speculate, however, that exploiting other germplasm
sources is necessary for sustaining long-term breeding progress in maize.
Received: 21 August 2000 / Accepted: 5 January 2001 相似文献
14.
A. Lehmensiek A.M. Esterhuizen D. van Staden S. W. Nelson A. E. Retief 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(5):797-803
Bulked segregant analysis was used to identify amplified fragment length polymorphism markers (AFLPs) linked to quantitative
trait loci (QTLs) involved in the resistance to gray leaf spot (GLS) in maize. By using ten AFLP primer combinations 11 polymorphic
markers were identified and converted to sequence- specific PCR markers. Five of the 11 converted AFLPs were linked to three
GLS resistance QTLs. The markers were mapped to maize chromosomes 1, 3 and 5 using existing linkage maps of two commercially
available recombinant inbred-line populations. Converted restriction fragment length polymorphism markers and microsatellite
markers were used to obtain a more-precise localization for the detected QTLs. The QTL on chromosome 1 was localized in bin
1.05/06 and had a LOD score of 21. A variance of 37% was explained by the QTL. Two peaks were visible on chromosome 5, one
was localized in bin 5.03/04 and the other in bin 5.05/06. Both peaks had a LOD score of 5, and 11% of the variance was explained
by the QTLs. A variance of 8–10% was explained by the QTL on chromosome 3 (bin 3.04). The consistency of the QTLs was tested
across two F2 populations planted in consecutive years.
Received: 10.10.00 / Accepted: 26.01.01 相似文献
15.
16.
H. Ma R. H. Busch O. Riera-Lizarazu H. W. Rines R. Dill-Macky 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(3-4):432-436
Anther culture and maize hybridization are two frequently used techniques for doubled haploid production in wheat (Triticum aestivum L.). Information on the field performance of lines derived from these techniques is limited. This study was conducted to
compare the performance of F4:6 lines obtained by single-seed descent with lines obtained by anther culture and maize (Zea mays L.) pollination from the same cross of spring wheat, ’Chris’/MN 7529. Thirty-three lines derived from each of those techniques
were evaluated in six environments for grain yield, protein content, test weight, heading date, kernel weight and plant height.
Mean performance of the single-seed descent lines exceeded performance of the anther culture lines for grain yield, kernel
weight and plant height with no apparent differences for grain protein content, test weight and heading date. No differences
between trait means for the single-seed descent and maize pollination lines were found except for plant height. The best 5
lines from each method for grain yield, protein content and test weight were similar in performance except that the protein
content was higher for the maize pollination lines than for the single-seed descent lines. Acceptable levels of agronomic
performance could be found among lines from each method. Wide acceptance of the doubled haploid technique for pure line production
in breeding programs may, however, be limited by the often poor efficiency of doubled haploid line production, resulting in
smaller population sizes for selection of desirable traits in comparison to the single-seed descent method.
Received: 31 July 1998 / Accepted: 28 November 1998 相似文献
17.
Inter-MITE polymorphisms (IMP): a high throughput transposon-based genome mapping and fingerprinting approach 总被引:9,自引:0,他引:9
R.-Y. Chang L. S. O’Donoughue T. E. Bureau 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(5):773-781
Miniature inverted-repeat transposable elements or MITEs represent a large superfamily of transposons that are moderately
to highly repetitive and frequently associated with plant genes. These attributes were exploited in the development of a powerful
marker technology called Inter-MITE polymorphism, or IMP, which involves the amplification between two adjacent MITEs. In
this report, we describe the utility of the IMP approach in the mapping and fingerprinting of the barley genome. MITEs were
systematically mined from barley genomic gene sequences by computer-assisted database searches and structural analysis. Barley
MITEs include members of the Stowaway family and a new family we have named Barfly. Using these barley MITEs, a total of 88 IMP markers were mapped onto an existing barley RFLP map that was based on a doubled-haploid
segregating population between Hordeum vulgare and Hordeum spontaneum. We demonstrate that the IMP approach can be effectively applied in the fingerprinting of barley cultivars and for genetic
similarity analysis. We also provide evidence that barley MITE-based primers can be effectively used in the mapping and fingerprinting
of other cereals, suggesting that the IMP approach has broad applicability.
Received: 24 March 2000 / Accepted: 28 July 2000 相似文献
18.
The maize rp1 rust resistance gene identifies homologues in barley that have been subjected to diversifying selection 总被引:1,自引:0,他引:1
M.A. Ayliffe N.C. Collins J.G Ellis A. Pryor 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(7):1144-1154
A number of agronomically important grasses (sorghum, wheat, panicum, sugar cane, oats, rice and barley) are shown to contain
sequences homologous to rp1, a maize gene that confers race-specific resistance to the rust fungus Puccinia sorghi. Mapping of rp1-related sequences in barley identified three unlinked loci on chromosomes 1HL, 3HL and 7HS. The locus located on chromosome
7HS comprises a small gene family of at least four members, two of which were isolated and are predicted to encode nucleotide
binding site-leucine-rich repeat (NBS-LRR) proteins that are respectively 58% and 60% identical to the maize rp1 protein. Evidence of positive selection for sequence diversification acting upon these two barley genes was observed; however,
diversifying selection was restricted to the carboxy terminal half of the LRR domain. One of these rp1 homologous genes cosegregated with the barley Rpg1 stem rust resistance gene amongst 148 members of the Steptoe × Morex double haploid mapping family. Three other unrelated
resistance gene-like sequences, potentially encoding NBS-LRR proteins, are also shown to be linked to the Rpg1 locus but not cosegregating with the gene.
Received: 2 August 1999 / Accepted: 28 September 1999 相似文献
19.
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
20.
Parental contribution and coefficient of coancestry among maize inbreds: pedigree, RFLP, and SSR data 总被引:3,自引:0,他引:3
R. Bernardo J. Romero-Severson J. Ziegle J. Hauser L. Joe G. Hookstra R. W. Doerge 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(3-4):552-556
The genetic relationship between inbreds i and j can be estimated from pedigree or from molecular marker data. The objectives of this study were to: (1) determine whether
pedigree, restriction fragment length polymorphism (RFLP), and simple sequence repeat (SSR) data give similar estimates of
parental contribution and coefficient of coancestry (f
ij
) among a set of maize (Zea mays L.) inbreds, and (2) compare the usefulness of RFLP and SSR markers for estimating genetic relationship. We studied 13 maize
inbreds with known pedigrees. The inbreds were genotyped using 124 RFLP and 195 SSR markers. For each type of marker, parental
contributions were estimated from marker similarity among an inbred and both of its parents, and were subsequently used to
estimate f
ij
. Estimates of parental contribution differed significantly (α<0.05) between pedigree data and either type of marker, but
not between the marker systems. The RFLP estimates of parental contribution failed to sum to 1.0, reflecting a higher frequency
of non-parental bands with RFLP than with SSR markers. The f
ij
estimated from pedigree, RFLP, and SSR data were highly correlated (r=0.87–0.97), although significant differences were found among the three sets of f
ij
estimates. We concluded that pedigree and marker data often lead to different estimates of parental contribution and f
ij
, and that SSR markers are superior to RFLP markers for estimating genetic relationship. A relevant question is whether or
not the inbreds previously genotyped with an older marker system (e.g., RFLP) need to be re-analyzed with a newer marker system
(e.g., SSR) for the purpose of estimating genetic relationship. Such re-analysis seems unnecessary if data for the same type
of marker are available for a given inbred and both of its parents.
Received: 2 June 1999 / Accepted: 30 July 1999 相似文献