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1.
R. Ortiz D. Vuylsteke 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,89(2-3):146-152
Black sigatoka (Mycosphaerella fijiensis Morelet), an airborne fungal leaf-spot disease, is a major constraint to plantain and banana (Musa spp.) production world-wide. Gaining further knowledge of the genetics of host-plant resistance will enhance the development of resistant cultivars, which is considered to be the most appropriate means to achieve stable production. Genetic analysis was conducted on 101 euploid (2x, 3x and 4x) progenies, obtained from crossing two susceptible triploid plantain cultivars with the resistant wild diploid banana Calcutta 4. Segregating progenies, and a susceptible reference plantain cultivar, were evaluated over 2 consecutive years. Three distinct levels of host response to black sigatoka were defined as follows: susceptible (< 8 leaves without spots), less susceptible (8–10) and partially resistant (> 10). Segregation ratios for resistance at the 2x level fitted a genetic model having one major recessive resistance allele (bs
1) and two independent alleles with additive effects (bsr
2 and bsr
3). A similar model explains the results at the 4x level assuming that the favourable resistance alleles have a dosage effect when four copies of them are present in their respective loci (bs
i
4
). The proposed model was further validated by segregation data of S
1 progenies. Mechanisms of black sigatoka resistance are discussed in relation to the genetic model. 相似文献
2.
The influence of ultraviolet (UV) radiation in simulated natural sunlight on the viability of ascospores of Mycosphaerella fijiensis, the cause of Black Sigatoka disease in banana and plantain, has been investigated as part of a study to assess the windborne
spread of this pathogen from mainland Central and South America into the Caribbean. Spores were killed following continuous
exposure to UV radiation for periods of 6 h or over. This relatively short exposure time suggests that the distances over
which viable spores can be transported will be determined not only by the speed of the wind but also the amount of cloud cover
and the time off day that spore release occurs. On this basis, wind dispersal of viable spores over distances greater than
a few hundred kilometres is unlikely. These conclusions are reinforced by an examination of historical reports of the arrival
of the disease in previously uninfected areas of the Americas and Africa.
Received: 10 February 1997 / Accepted: 30 March 1998 相似文献
3.
Effect of arbuscular mycorrhizal fungi on the acclimatization of micropropagated banana plantlets 总被引:1,自引:0,他引:1
A. M. Yano-Melo L. C. Maia O.J. Saggin Jr. J. M. Lima-Filho N. F. Melo 《Mycorrhiza》1999,9(2):119-123
The effect of arbuscular mycorrhizal fungi (AMF) on micropropagated banana plantlets was evaluated during the acclimatization
period. Plants were inoculated with Acaulospora scrobiculata, Glomus clarum or Glomus etunicatum. After cultivation in a greenhouse for 3 months, height, leaf area, fresh weight and dry matter of root and shoots, level
of AMF colonization, nutrient level, photosynthesis and transpiration rate, water potential and stomatal conductance were
measured. The number of AMF spores produced in each treatment was also determined. Plantlets inoculated with AMF had greater
height, leaf area and fresh weight of shoots and roots, as well as higher rates of photosynthesis and transpiration than controls.
Plants inoculated with Glomus were superior in most of the evaluated parameters.
Accepted: 24 May 1999 相似文献
4.
Identifying different types of de-differentiated microspores from indica-japonica F1 hybrids with subspecies-differentiating RFLP probes in rice 总被引:1,自引:0,他引:1
J. -H. Xie M. -W. Gao J. Lu J. -Y. Zhuang H. -X. Lin H. -R. Qian K. -L. Zheng 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):34-38
The indica, japonica and intermediary types of de-differentiated microspores from indica-japonica
hybrids were identified with 11 subspecies-differentiating RELP probes in rice (Oryza sativa L.). The results showed that the distribution of indica, japonica and intermediary types of de-differentiated microspores could be easily detected in a simple and quick way using the RFLP
method. Moreover, the microspores from the same hybrid but inoculated onto different media, or microspores from different hybrids when inoculated onto the same medium, often displayed distinctive distribution curves of de-differentiated microspores
types, indicating that the media employed in this experiment had high selectivity for the de-differentiation of certain types
of microspores. The application of the RELP method to de-differentiated microspore identification is of great theoretical
and practical significance in rice doubled-haploid breeding.
Received: 27 February 1996 / Accepted: 14 June 1996 相似文献
5.
Rodomiro Ortiz 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(8):1113-1120
Several primary tetraploids with desirable attributes have been selected by Musa breeding programs. Diploid parental stocks have become available for further genetic improvement of the Musa genome. Hence, new genome manipulations should be tested before they become routine in breeding programs. Through comparison
of the performance of triploid landraces, their primary tetraploid hybrids and secondary polyploid derivatives, plus diploid
ancestors, it was found that the production of secondary triploids (TM3x) is more rewarding than developing secondary tetraploids.
TM3x achieved significant high polyploid-parent heterosis for yield either by maximizing heterozygosity through crosses between
unrelated parents, or by selection of linkats in hybrids derived from crosses between euploid full-sibs. There were significant
differences in bunch weight between full-sib secondary polyploids, which suggested that specific combining ability should
be re-defined considering not only a specific cross combination but also the individual performance within each cross. This
paper proposes a crop-breeding strategy which takes into consideration the process of domestication of banana and plantain.
Current data suggest that this type of evolutionary breeding approach may be feasible in Musa.
Received: 10 September 1996/Accepted: 31 January 1997 相似文献
6.
Quantitative trait loci for resistance against Yellow rust in two wheat-derived recombinant inbred line populations 总被引:3,自引:0,他引:3
Boukhatem N Baret PV Mingeot D Jacquemin JM 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(1):111-118
Yellow rust, which is a major disease in areas where cool temperatures prevail, can strongly influence grain yield. To control
this disease, breeders have extensively used major specific resistance genes. Unfortunately this kind of resistance is rapidly
lost due to pathogen adaptation. More-durable resistance against yellow rust can be achieved using quantitative resistance
derived from cultivars with well-established durable resistance. The winter wheat Camp Remy has maintained a high level of
resistance for over 20 years. In order to map quantitative trait loci (QTLs) for durable yellow rust resistance, we analysed
a set of 98 F8 recombinant inbred (RI) lines derived from the cross Camp Remy×Michigan Amber. We also mapped QTLs for adult resistance to
yellow rust using the International Triticae Mapping Initiative RI population (114 lines derived from the cross Opata85×synthetic
hexaploid). Two and five QTLs, respectively, were identified from these two populations. This work has highlighted the importance
of the centromeric region of chromosome 2B and the telomeric regions of chromosomes 2AL and 7DS in durable yellow rust resistance.
The same chromosomal regions are also implicated in resistance to other pathogens.
Received: 8 December 2000 / Accepted: 17 April 2001 相似文献
7.
L. S. Arraiano A. J. Worland C. Ellerbrook J. K. M. Brown 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(5):758-764
Septoria tritici blotch, caused by the fungus Mycosphaerella graminicola,is currently the major foliar disease of wheat world-wide, and new sources of resistance and knowledge about the genetics
of resistance are needed to improve breeding for resistance to this disease. Sears’s ’Synthetic 6x’ hexaploid wheat, derived from a hybrid of Triticum dicoccoides and Triticum tauschii, was resistant to 12 of 13 isolates of M. graminicola tested. Chromosome 7D of ’Synthetic 6x’ was identified as carrying resistance to all 12 isolates in tests of seedlings of inter-varietal chromosome substitution
lines of ’Synthetic 6x’ into ’Chinese Spring’ and to two isolates in tests of adult plants. A septoria tritici blotch resistance gene, named Stb5, was identified using the M. graminicola isolate IPO94269 and mapped on the short arm of chromosome 7D, near the centromere, in a population of single homozygous
chromosome-recombinant lines for the 7D chromosome.
Received: 1 February 2001 / Accepted: 17 April 2001 相似文献
8.
T. Krugman A. Korol E. Nevo J. W. Snape O. Levy B. Rubin 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):46-51
Chlorotoluron is a selective phenylurea herbicide widely used for broad-leaved and annual grass weed control in cereals. Variation in the response to chlorotoluron (CT) was found in both hexaploid bread wheat (Triticum aestivum L.) and wild tetraploid wheat (Triticum dicoccoides KöRN.). Here, we describe the comparative mapping of the CT resistance gene (Su1) on chromosome 6B in bread and wild wheat using RFLP markers. In bread wheat, mapping was based on 58 F4 single-seed descent (SSD) plants of the cross between a genotype sensitive to chlorotoluron, ‘Chinese Spring’ (CS), and a resistant derivative, the single chromosome substitution line, CS (‘Cappele-Desprez’ 6B) [CS (CAP6B). In T dicoccoides, mapping was based on 37 F2 plants obtained from the cross between the CT-susceptible accession B-7 and the resistant accession B-35. Nine RFLP probes spanning the centromere were chosen for mapping. In bread wheat Su1 was found to be linked to α-Amy-1 (9.84 cM) and Xpsr371 (5.2 cM), both on the long arm of 6B, and Nor2 (2.74 cM) on the short arm. In wild wheat the most probable linkage map was Nor2-Xpsr312-Su1-Pgk2, and the genetic distances between the genes were 24.8cM, 5.3cM, and 6.8cM, respectively. These results along with other published map data indicate that the linear order of the genes is similar to that found in T. aestivum. The results of this study also show that the Su1 gene for differential response to chlorotoluron has evolved prior to the domestication of cultivated wheat and not in response to the development and use of chemicals. 相似文献
9.
Oenothera villaricae Dietrich and Oe. picensis Dietrich, complete translocation heterozygotes, are fully interfertile, giving rise to six discrete classes of true-breeding
hybrids from a reciprocal cross. Associated with each parent and hybrid is a characteristic abortive non-staining pollen fraction
easily distinguished from fully developed pollen under the light microscope. Pollen abortion has been associated with translocation
rings in other angiosperm species, and may characterize such systems. The abortive pollen fraction is significantly different
between reciprocal Oenothera hybrids, however (P<0.001), indicative of partial cytoplasmic control. Pollen abortion is most severe in the F1 hybrid generation, and ameliorates with successive generations of hybrid self-fertilization. Three-way analysis of variance
shows significant effects on pollen stainability (a measure of the non-abortive fraction) for nucleus, cytoplasm and selfed
hybrid generation, individually or in combinations. This result suggests a combined nucleocytoplasmic basis for the pollen
abortion. Correlated with the observation of increased pollen abortion in Oenothera hybrids are meiotic findings of broken chromosome rings (chains, univalents), asymmetric anaphase chromosome distributions
and trinucleate tetrads. To test the hypothesis that such anomalous meiotic events play a role in the mechanism of pollen
abortion, meiotic disjunction frequency was determined for each parent, F1 and F9 selfed hybrid accessions. Three-way analysis of variance shows levels of significance comparable to those noted for pollen
stainability (P<0.001) for effects of nucleus, cytoplasm and selfed hybrid generation on disjunction frequency. A high degree of correlation
(r
2=0.984) is noted between disjunction frequency and pollen stainability. We conclude that the abortive pollen grains are indeed
the products of nondisjunctional meiotic events, which themselves are consequences of hybrid nucleocytoplasmic incompatibility.
Received: 28 May 1997 / Revision accepted: 23 July 1997 相似文献
10.
G. Sills J. Nienhuis 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(1-2):275-282
Recurrent selection for specific combining ability (RS-SCA) and S1 family performance (RS-S1) were compared in replicated
selection programs initiated from a common C0 base population of Arabidopsis. Three cycles of selection for aerial biomass were completed in each of two replicate programs of each selection method.
Response to selection was measured on the basis of per se, S1 progeny, and testcross performance with a common tester. All
selection programs improved testcross performance. Testcross gain per cycle in RS-S1 (7.15% cycle-1) and RS-SCA (5.31% cycle-1) were not significantly different. Performance of S1 progeny and populations per se significantly improved over cycles of
selection using RS-S1 but were unchanged by RS-SCA. Codominant molecular marker-allele frequencies were recorded for each
population at 22 polymorphic loci. Trends in marker-allele frequencies were tested by linear regression. Significant trends
in marker-allele frequencies pooled over replicate programs were detected at 8 and 7 loci in the RS-S1 and RS-SCA programs,
respectively. Marker alleles at 2 loci significantly changed frequency in response to both RS-S1 and RS-SCA programs. Marker
alleles at 6 loci significantly changed frequency only in response to RS-SCA. Marker alleles at 6 other loci showed significant
linear trends pooled over replicates only in RS-S1. No markers revealed increases in the frequency of different marker alleles
within loci using the two selection methods. Possible genetic causes of marker frequency changes are discussed, as well as
breeding implications. 相似文献
11.
Organization of an Arabidopsis thaliana gene cluster on chromosome 4 including the RPS2 gene, in the Brassica nigra genome 总被引:5,自引:0,他引:5
J. Sadowski C. F. Quiros 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(3-4):468-474
Genetic and physical maps, consisting of a large number of DNA markers for Arabidopsis thaliana chromosomes, represent excellent tools to determine the organization of related genomes such as those of Brassica. In this paper we report the chromosomal localization and physical analysis by pulsed-field gel electrophoresis (PFGE) of
a well-defined gene complex of A. thaliana in the Brassica nigra genome (B genome n=8). This complex is approximately 30 kb in length in A. thaliana and contains a cluster of six genes including ABI1 (ABA-responsive), RPS2 (resistance against Pseudomonas syringae, a bacterial disease), CK1 (casein kinase I), NAP (nucleosome-assembly protein), X9 and X14 (both of unknown function). The Arabidopsis chromosomal complex was found to be duplicated and conserved in gene number at different levels in the Brassica genome. Linkage group B1 had the most-conserved arrangement carrying all six genes tightly linked. Group B4 had an almost
complete complex except for the absence of RPS2. Other partial complexes of fewer members were found on three other chromosomes. Our studies demonstrate that by this approach
it is possible to identify ancestrally related chromosome segments in a complex and duplicated genome, such as the genome
of B. nigra, permitting one to draw conclusions as to its origin and evolution.
Received: 11 July 1997 / Accepted: 9 October 1997 相似文献
12.
Field assessments of gene flow from transgenic to cultivated rice (Oryza sativa L.) using a herbicide resistance gene as tracer marker 总被引:6,自引:0,他引:6
J. Messeguer C. Fogher E. Guiderdoni V. Marfà M. M. Català G. Baldi E. Melé 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(8):1151-1159
Development of plant genetic engineering has led to the deployment of transgenic crops and, simultaneously, to the need for
a thorough assessment of the risks associated with their environmental release. This study investigated the occurrence of
gene flow from transgenic rice to non-transgenic rice plants under agronomic conditions using a herbicide resistance gene
as a tracer marker. Two field experiments were established in the paddy fields of two main Mediterranean rice-growing areas
of Spain and Italy. In both locations analyses of phenotypic, molecular and segregation data showed that pollination of recipient
plants with pollen of the transgenic source occurred at a significant frequency. A gene flow slightly lower than 0.1% was
detected in a normal side-by-side plot design. Similar results were found in a circular plot when the plants were placed at
1-m distance from the transgenic central nucleus. A strong asymmetric distribution of the gene flow was detected among this
circle and highest values (0.53%) were recorded following the direction of the dominant wind. A significant lowest value (0.01%)
was found in the other circle (5 m from the transgenic plants) as was expected according to the characteristics of rice pollen.
Such circular-field trial designs could also prove to be very useful in studying the gene flow to other commercial cultivars
of rice with the aim of establishing strategies to prevent pollen dispersal from commercial transgenic fields to the neighbouring
conventional fields.
Received: 23 February 2001 / Accepted: 31 March 2001 相似文献
13.
14.
15.
R. Finkeldey O. Murillo 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(3-4):664-668
The concept of the partitioning of genetic diversity into a component within and a component among populations (F
ST
- or G
ST
-statistics) can be easily expanded to compute the contribution of single subpopulations to total gene diversity. A subpopulation
contributes to total gene diversity with its single-population gene diversity plus the (weighted) mean of Nei’s minimum genetic
distances to all subpopulations. The suggested method allows one to unambiguously rank subpopulations according to the amount
they contribute to the total gene diversity. Genetic polymorphisms at four isozyme gene loci of Alnus acuminata in Costa Rica are used to illustrate the procedure and its biological interpretation.
Received: 15 August 1998 / Accepted: 8 September 1998 相似文献
16.
Generation of a soybean BAC library, and identification of DNA sequences tightly linked to the Rps1-k disease resistance gene 总被引:5,自引:0,他引:5
S. S. Salimath M. K. Bhattacharyya 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(5):712-720
A soybean bacterial artificial chromosome (BAC) library, comprising approximately 45 000 clones, was constructed from high-molecular-weight
nuclear DNA of cultivar Williams 82, which carries the Rps1-k gene for resistance against Phytophthora sojae. The library is stored in 130 pools with about 350 clones per pool. Completeness of the library was evaluated for 21 random
sequences including four markers linked to the Rps1 locus and 16 cDNAs. We identified pools containing BACs for all sequences except for one cDNA. Additionally, when screened
for possible contaminating BAC clones carrying chloroplast genes, no sequences homologous to two barley chloroplast genes
were found. The estimated average insert size of the BAC clones was about 105 kb. The library comprises about four genome
equivalents of soybean DNA. Therefore, this gives a probability of 0.98 of finding a specific sequence from this library.
This library should be a useful resource for the positional cloning of Rps1-k, and other soybean genes. We have also evaluated the feasibility of an RFLP-based screening procedure for the isolation
of BAC clones specific for markers that are members of repetitive sequence families, and are linked to the Rps1-k gene. We show that BAC clones isolated for two genetically linked marker loci, Tgmr and TC1-2, are physically linked. Application of this method in expediting the map-based cloning of a gene, especially from
an organism, such as soybean, maize and wheat, with a complex genome is discussed.
Received: 12 May 1998/Accepted: 24 August 1998 相似文献
17.
Genetic analysis of durable leaf rust resistance in winter wheat 总被引:8,自引:0,他引:8
M. M. Messmer R. Seyfarth M. Keller G. Schachermayr M. Winzeler S. Zanetti C. Feuillet B. Keller 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(3-4):419-431
Quantitative resistance that delays the epidemic development of leaf rust in wheat is an important source for durable resistance
breeding. The Swiss winter wheat variety ’Forno’ shows a high level of quantitative resistance against leaf rust. This resistance
has been effective for more than 10 years and can therefore be considered to be durable. In order to map quantitative trait
loci (QTL) for durable leaf rust resistance we analysed 204 F5 recombinant inbred lines (RILs) of the cross between the winter wheat ’Forno’ and the winter spelt ’Oberkulmer’ for their
level of leaf rust resistance (LR) and leaf tip necrosis (LTN) in four different environments. Both traits showed a continuous
distribution and were significantly correlated (r=−0.5). Across environments we detected 8 QTL for leaf rust resistance (6 inherited from ’Forno’) and 10 QTL for the quantitative
expression of LTN (6 inherited from ’Forno’). Of the 6 QTL responsible for the durable leaf rust resistance of ’Forno’, 1
major QTL coincided with a thaumatin locus on 7BL explaining 35% of the phenotypic variance. Four QTL for LR coincided with
QTL for LTN. At these loci the alleles of ’Forno’ increased the level of resistance as well as the extent of LTN, indicating
pleiotropy.
Received: 1 July 1999 / Accepted: 30 July 1999 相似文献
18.
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
19.
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