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1.
Crown rust, Puccinia coronata Corda, causes one of the most damaging foliar diseases in Italian ryegrass, Lolium multiflorum Lam. For introgression of crown rust resistance, highly resistant hybrids of the crosses Festuca arundinacea (2n = 6x = 42) ×L. multiflorum (2n = 4x = 28) and reciprocally, L. multiflorum (2n = 2x = 14) ×Festuca pratensis (2n = 4x = 28) and subsequently resistant recombinant individuals were used as female parents and susceptible cultivars of Italian ryegrass as male parents in three successive backcrosses. The BC3 plants were selfed and crossed mutually. Uredospores of seven different crown rust isolates collected from plants of L. multiflorum, Lolium perenne, F. pratensis, F. arundinacea and L. multiflorum × F. pratensis hybrids were applied to identify the resistance or susceptibility of the parental species, backcrossed, selfed and intercrossed progenies. The various crown rust populations revealed a species-specific capability to infect plants of the Lolium-Festuca complex corresponding to the host species from which the spores originated. Selected BC9 plants, however, were found to be completely resistant to all crown rust populations tested. Successful introgression of the resistance was achieved from F. arundinacea as well as from F. pratensis. The resistance represents a dominant character, apparently based on a strong heterologous incompatibility between host and pathogen. In phenotype, bivalent formation during meiosis and in fertility, the novel germplasms are comparable with the L. multiflorum cultivars. 相似文献
2.
Summary The oat line Pc54 was found to be resistant to powdery mildew under both field and glasshouse conditions. The ratio of resistant to susceptible F2 and F2 progeny of a cross between a selection from the Pc54 line (Cc7422) and a susceptible cultivar (Selma) showed that, in addition to carrying the crown rust resistance gene Pc54 and the pg15 gene for stem rust resistance, the mildew resistance of the Pc54 line was conditioned by a single incompletely dominant gene along with additional factors which modified the expression of resistance. Previous results, that there was no linkage between genes Pc54 and Pg15, were confirmed. In addition, there was no evidence of linkage between the mildew resistance gene and gene Pc54. Evaluation of selections from within the Pc54 line showed that the expression of both stem rust and mildew resistance was modified by, or linked to, plant height. The effectiveness of genes Pc54 and Pg15, as measured by virulence frequencies, in central and eastern Europe is described. 相似文献
3.
Differences were found in the expression of resistance of perennial ryegrass, Lolium perenne, cultivars to crown rust, Puccinia coronata Corda, when plants were incubated at either 10°C or 25°C. In an extreme example, all the genotypes of ‘Carrick’ were resistant at 10°C but susceptible at 25°C. The variation between cultivars was due both to a general increase in expression of susceptibility and the proportion of plants which became susceptible. A BC1 line containing a stay‐green gene derived from Festuca pratensis was insensitive to temperature, while a sister line was sensitive. 相似文献
4.
Forty stem rust resistant oat cultivars and lines were selected from Australian oat breeding programs, Quaker Oat Nurseries and a Brazilian oat collection. Most, including the Pg-a reference stock Omega, were crossed with a susceptible line in order to study the inheritance of resistance. Omega was crossed with 15 resistant selections and a further 15 intercrosses were made among resistant selections. All selected lines possessed Pg-a which was inherited as a pair of recessive complementary genes. All crosses among resistant lines failed to segregate. In the majority of resistant/susceptible crosses, the F2 ratio was 1 resistant: 2 intermediate: 13 susceptible, whereas in others it was 1 resistant: 15 susceptible. Progenies of plants with intermediate reactions always segregated. Although Kyto with Pg-12 was a parent of Omega, Pg-12 was not present in any resistant line and was not involved in the Pg-a response. The respective complementary genes were isolated in stem rust susceptible lines, which when intercrossed, segregated in F2 to produce resistant plants in the expected frequencies and with the typical Pg-a phenotype. The lack of effective genetic variability for stem rust resistance among important sources of germplasm used by Australian oat breeders is a major cause for concern. 相似文献
5.
The main goal of this work was to introduce resistance genes for rust, caused by Uromyces appendiculatus, and anthracnose, caused by Colletotrichum lindemuthianum, in an adapted common bean cultivar through marker-assisted backcrossing. DNA fingerprinting was used to select plants genetically closer to the recurrent parent which were also resistant to rust and to race 89 of C. lindemuthianum. DNA samples extracted from the resistant parent (cv. Ouro Negro), the recurrent parent (cv. Rudá), and from BC1, BC2 and BC3 resistant plants were amplified by the RAPD technique. The relative genetic distances in relation to the recurrent parent varied between 9 and 59% for BC1, 7 and 33% for BC2, and 0 and 7% for BC3 resistant plants. After only three backcrosses, five lines resistant to rust and anthracnose with, approximately, 0% genetic distance in relation to the recurrent parent were obtained. These lines underwent field yield tests in two consecutive growing seasons and three of them presented a good yield performance, surpassing in that sense their parents and most of the reference cultivars tested. 相似文献
6.
Greenhouse and field techniques for testing sugar beet for resistance to Rhizoctonia root and crown rot 总被引：1，自引：0，他引：1
Rhizoctonia‐resistant sugar beet varieties are the key to an integrated control strategy for Rhizoctonia root rot. Because of the unpredictable occurrence of Rhizoctonia solani in the field testing of sugar beet for resistance to Rhizoctonia root rot is difficult. The aim of the study was to develop advanced greenhouse and field techniques which allow a reliable assessment of sugar beet for resistance to R. solani. A highly infectious liquid inoculum was used for the first time in this study. It can be produced in large quantities of a standardized quality, sterile, and exactly quantified according to its carbon content. In a greenhouse trial, sugar beet grown in the same way as field grown beet was inoculated by applying a suspension of Rhizoctonia mycelium (equivalent to 10 mg carbon per plant) to the beet crown. After 3 weeks, inoculation had led to uniform and severe root rot. Disease symptoms were similar to those found under natural conditions in the field. No ‘escapes’, i.e. susceptible plants apparently expressing resistance were observed in the test. A new nine‐class disease scale was established and a Rhizoctonia index (RI) was calculated. Reliability of disease assessment was demonstrated on progeny of plants, selected from segregating populations, showing Rhizoctonia resistance more closely related to the resistant parent lines than to the susceptible ones. Sugar beet varieties could be assessed in the greenhouse within only 11 weeks. All varieties were affected by the pathogen but partially resistant varieties could be clearly recognized by a significantly lower Rhizoctonia index. Significant differences in susceptibility were also found within the group of new resistant genotypes. Infection studies performed in the field showed the superiority of the new liquid inoculum compared with a solid form and revealed the influence of inoculation date and inoculum level on the development of Rhizoctonia root rot. In field tests performed at different sites under different environmental conditions, susceptible and partially resistant sugar beet varieties could be reproducibly rated according to their susceptibility to R. solani. On average, susceptible varieties showed a Rhizoctonia index of 8 while resistant genotypes ranged from 5 to 6. The newly developed techniques allow fast and reliable evaluation of sugar beet for resistance to R. solani. 相似文献
7.
Sources of partial resistance to crown rot caused by Fusarium pseudograminearum are detected in mature plants grown in artificially inoculated soil in the field. The resistance in most but not all of these
sources can also be detected in seedlings. In order to determine whether partial resistance is related to depth of crown formation,
this character was measured in 13 cultivars/lines with a range of reaction to crown rot. It was also measured in doubled haploid
plants from the cross, Batavia/2–49. Crown depths varied from 17.1 mm to -2.3 mm (above ground) in pots in a waterbath at
25 °C and from 43.5 mm to 20.7 mm when plants were grown in the field. The correlation coefficient between relative susceptibility
to crown rot (Field test) and crown depth of 13 cultivars/lines was 0.57 (p ≤ 0.05). With the exception of the cultivars, Sunco and Pelsart, partial resistance to crown rot was inversely related to
depth of crown formation. This indicates that depth of crown formation may be partly responsible for the reaction of a cultivar/line
to crown rot. Depth of crown formation was also measured in susceptible and partially resistant cultivars/lines grown from
seed planted at different depths. As depth of seeding increased, depth of crown formation in partially resistant and susceptible
cultivars/lines increased in similar proportions.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
Summary Hexaploid and octoploid tritordeums and their parents Hordeum chilense and Triticum spp. were screened for resistance to isolates of wheat and barley yellow and brown rusts. All H. chilense lines were highly resistant to both wheat and barley brown rust, few lines were susceptible to wheat yellow rust while susceptibility to barley yellow rust was common. In general the resistance of tritordeum is predominantly contributed by the wheat parent and apparently the genes for resistance in H. chilense are inhibited in their expression by the presence of the wheat genome.Abbreviations WYR
wheat yellow rust
- WBR
wheat brown rust
- BYR
barley yellow rust
- BBR
barley brown rust 相似文献
9.
Groundnut rust (Puccinia arachidis Speg.) is an important air borne pathogen, which causes substantial losses in groundnut yield and quality. Although large
numbers of accessions were identified as rust resistant in wild, interspecific derivative and cultivated groundnut species,
transfer of resistance to well-adapted cultivars is limited due to linkage drag, which worsens yield potential and market
acceptance. A F2 mapping population comprising 117 individuals was developed from a cross between the rust resistant parent VG 9514 and rust
susceptible parent TAG 24. Rust resistance was governed by single dominant gene in this cross. We identified 11 (out of 160)
RAPD primers that exhibited polymorphism between these two parents. Using a modified bulk segregant analysis, primer J7 (5′CCTCTCGACA3′)
produced a single coupling phase marker (J71350) and a repulsion phase marker (J71300) linked to rust resistance. Screening of the entire F2 population using primer J7 revealed that the coupling phase marker J71350 was linked with the rust resistance gene at a distance of 18.5 cM. On the other hand, the repulsion phase marker J71300 was completely linked with rust resistance. Additionally, both J71300 (P = 0.00075) and J71350 (P < 0.00001) were significantly associated with the rust resistance. Marker J71300 identified all homozygous rust resistant genotypes in the F2 population and was present in all the eight susceptible genotypes tested for validation. Thus, J71300 should be applicable for marker-assisted selection (MAS) in the groundnut rust resistance breeding programme in India. To
the best of our knowledge this is the first report on the identification of RAPD markers linked to rust resistance in groundnut. 相似文献
10.
A microsatellite marker linked to leaf rust resistance transferred from Aegilops triuncialis into hexaploid wheat 总被引：1，自引：0，他引：1
Aegilops triuncialis (UUCC) is an excellent source of resistance to various wheat diseases, including leaf rust. Leaf rust‐resistant derivatives from a cross of a highly susceptible Triticum aestivum cv.‘WL711’ as the recurrent parent and Ae. triuncialis Ace.3549 as the donor and with and without a pair of acrocentric chromosomes were used for molecular tagging. The use of a set of sequence tagged microsatellite (STMS) markers already mapped to different wheat chromosomes unequivocally indicated that STMS marker gwm368 of chromosome 4BS was tightly linked to the Ae. triuncialis leaf rust resistance gene transferred to wheat. The presence of the Ae. Triuncialis‐specific STMS gwm368 homoeoallele along with the non‐polymorphic 4BS allele in the rust‐resistant derivatives with and without the acrocentric chromosome indicates that the resistance has been transferred from the acrocentric chromosome to either the A or the D genome of wheat. This alien leaf rust resistance gene has been temporarily named as LrTr. 相似文献
11.
Sharanabasappa B. Yeri Kenta Shirasawa Manish K. Pandey M. V. C. Gowda Vanhi Sujay Manda Shriswathi Hajisaheb L. Nadaf Babu N. Motagi S. Lingaraju A. R. S. Bhat Rajeev K. Varshney P. U. Krishnaraj Ramesh S. Bhat 《Plant Breeding》2014,133(1):80-85
Heterogeneous inbred families segregating for rust resistance were identified from the two crosses involving susceptible (TAG 24 and TG 26) and resistant (GPBD 4) varieties of peanut. Rust‐resistant (less than score 5) and rust‐susceptible (more than score 5) plants were identified in each HIF and evaluated under rust epiphytotic conditions. The set of plants belonging to the same HIF, but differing significantly in rust resistance, not in other morphological and productivity traits, was regarded as near‐isogenic lines (NILs). Largely, rust‐resistant NILs had GPBD 4‐type allele, and susceptible NILs carried either TAG 24 or TG 26‐type allele at the three SSR loci (IPAHM103, GM1536 and GM2301) linked to a major genomic region governing rust resistance. Comparison of the remaining genomic regions between the NILs originating from each of the HIFs using transposon markers indicated a considerably high similarity of 86.4% and 83.1% in TAG 24 × GPPBD 4 and TG 26 × GPBD 4, respectively. These NILs are useful for fine mapping and expression analysis of rust resistance. 相似文献
12.
P. W. Wilkins 《Euphytica》1978,27(3):837-841
Summary Cultures of crown rust (Puccinia coronata
Corda) from a mixed uredospore population obtained from plants in 16 localities in England and Wales were multiplied on four of 10 initially resistant clones of Italian ryegrass (Lolium multiflorum
Lam.). Only two of the four cultures were found to be most pathogenic on the clones on which they had been multiplied. One clone became very susceptible to its own culture but the other became only moderately susceptible. Clone/culture interactions occurred which were not obviously related to the clone of origin of the culture. Thus, there was considerable genetic diversity in the crop which would tend to limit the multiplication of new races. There was a strong correlation between visual score for susceptiblity and uredospore production, showing the value of visual scores for resistance breeding. 相似文献
13.
Present status of genetics of rust resistance in flax 总被引：5，自引：0，他引：5
Summary Present knowledge of host genes conferring resistance to rust in flax and their genetics are reviewed. There are at least 34 genes conferring resistance to rust occurring in seven groups, namely, K, L, M, N, P, D and Q. Expression of these host genes is affected by temperature, genetic background and by the inhibitor gene present in certain rust strains. Recombination analysis indicates that genes within each of the M and N groups are probably closely linked and that of the L group are genetically complex. When testcross progeny between two genes of the L group were screened, susceptible and modified recombinants were recovered. Some of these susceptible recombinants yielded rare resistant revertants in their progeny. Mechanism of such reversion is not defined but appears to follow a definite pattern. It is also indicated that some of the recombinants represent new specificity. A molecular approach of cloning host genes in flax is described. 相似文献
14.
An interspecific cross was made to transfer leaf rust and stripe rust resistance from an accession of Aegilops ovata (UUMM) to susceptible Triticum aestivum (AABBDD) cv. WL711. The F1was backcrossed to the recurrent wheat parent, and after two to three backcrosses and selfing, rust resistant progenies were
selected. The C-banding study in a uniformly leaf rust and stripe rust resistant derivative showed a substitution of the 5M
chromosome of Ae. ovata for 5D of wheat. Analysis of rust resistant derivatives with mapped wheat microsatellite makers confirmed the substitution
of 5M for 5D. Some of these derivatives also possessed one or more of the three alien translocations involving 1BL, 2AL and
5BS wheat chromosomes which could not be detected through C-banding. A translocation involving 5DSof wheat and the substituted
chromosome 5M of Ae. ovata was also observed in one of the derivatives. Susceptibility of this derivative to leaf rust showed that the leaf rust resistance
gene(s) is/are located on short arm of 5M chromosome of Ae. ovata. Though the Ae. ovatasegment translocated to 1BL and 2AL did not seem to possess any rust resistance gene, the alien segment translocated to 5BS
may also possess gene(s) for rust resistance. The study demonstrated the usefulness of microsatellite markers in characterisation
of interspecific derivatives.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
15.
Summary Reciprocal crosses were carried out between Triticum dicoccoides sel. G-25-highly resistant to Puccinia striiformis race 20A-and Triticum durum cultivar Nursith 163-which served as susceptible parent.F1 hybrids in one of the crosses showed a wide range of infection types to the test isolate, whereas in a repeated cross all F1 plants proved highly resistant. The variable reaction pattern observed in the F1 hybrids of the first cross suggests incomplete penetrance of the resistance factor in certain environmental conditions.The segregation ratio displayed by the F2 progenies indicates that a single dominant factor for resistance to stripe rust race 20A was transferred from wild emmer to cultivated durum wheat.Contribution from the Agricultural Research Organization, Volcani Center, Bet Dagan, Israel. 1973 Series, No. 291-E. 相似文献
16.
对衍生于普通小麦与八倍体小偃麦‘小偃7430’杂种后代的抗条锈病新种质CH7102进行抗性鉴定和遗传分析,明确其抗性来源及其遗传方式。采用条锈菌流行小种CYR31、CYR32对CH7102及其亲本进行苗期抗性评价;对CH7102分别与感病品种和已知抗性基因载体品系的杂交后代接种CYR32进行成株期抗条锈性遗传分析和等位性测验。CH7102具有与其抗病亲本‘小偃7430’和彭提卡偃麦草相似的侵染型,而所有的小麦亲本均感病,表明CH7102的抗性来自彭提卡偃麦草;CH7102与感病品种‘台长29’和‘绵阳11’杂交、回交,其F2、BC1、F2:3代的抗、感分离比分别符合3:1、1:1和1:2:1的单显性基因分离模式。而CH7102与已知抗性基因载体品系杂交F2代的抗感分离比为15:1。CH7102对条锈病的抗性来自彭提卡偃麦草,其抗性受1对显性核基因控制,而且与已知的抗CYR31、CYR32的抗性基因Yr5、Yr10、Yr15、Yr24/Yr26、Yr41不存在等位关系,属新的抗条锈病基因。 相似文献
17.
Downy mildew, incited by Peronospora parasitica (Pers.: Fr.) Fr., is a destructive disease of broccoli (Brassica oleraceaL., Italica Group). Resistant cultivars represent a desirable control method to provide a practical, environmentally benign,
and long-term means of limiting damage from this disease. Doubled-haploid (DH) lines developed by us exhibit a high level
of downy mildew resistance at the cotyledon stage. To determine the mode of inheritance for this resistance, a resistant DH
line was crossed to a susceptible DH line to make an F1, from which F2 and backcross (BC) populations were developed. All populations were evaluated for response to artificial inoculation with
P. parasitica at the cotyledon stage. All F1 plants (including reciprocals) were as resistant as the resistant parent, indicating no maternal effect for this trait. F2 populations segregated approximately 3resistant to 1 susceptible, BC populations using the resistant parent as the recurrent
parent contained all resistant plants, and the BC to the susceptible parent segregated 1 resistant to 1 susceptible. These
results indicate that resistance is controlled by a single dominant gene. This gene should be easily incorporated into F1 hybrids and used commercially to prevent downy mildew at the cotyledon stage.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
18.
Resistance to the prevailing races of sunflower rust, Puccinia hehanthi Schw., is lacking in the commercial hybrids (Helianthus annuus L.). The objective of this study was to identify new sources of resistance to the four North American rust races in wild Helianthus species, and to determine their mode of inheritance. Seventy-eight accessions of H. annuus L., H. argophyllus Torrey and Gray, and H. petiolans Nutt. were evaluated in the greenhouse. Resistance to races 1, 2, 3, and 4 was observed in 25, 28, 15, and 26% of the plants, respectively, and 10% of the plants were resistant to all four races. Seven accessions that had a high percentage of resistant plants to all the four races were selected and one resistant plant from each accession was crossed with susceptible inbred line HA89. Three to four F1 plants resistant to all four races from each cross were backcrossed with HA89. F1 plants from PI-413118 × HA89 and PI 413175 × HA89 were resistant to all four races. The PI 413023 × HA89 F1 plants were 100 % resistant to races 3 and 4 and segregated in a 3: 1 resistant (R) to susceptible (S) ratio to races 1 and 2. The other four F1 combinations segregated 3R: IS ratios to all four races. Bc1F1 progenies revealed that plants from PI 413048, PI 413037, PI 413038, and PI 413171 used in the crosses possessed two dominant genes in heterozygous condition for resistance to each of the four races, whereas plants from PI 413023 possessed two dominant genes in heterozygous condition for resistance to each of races 1 and 2, and one dominant resistance gene in homozygous condition for each of races 3 and 4. Plants from PI 413118 and PI 413175 carried a single dominant gene in homozygous condition for resistance against each of the four races. 相似文献
19.
Doubled haploid lines derived from anther culture of two Iranian spring wheat genotypes‘Ghods’susceptible and‘9106’resistant to yellow rust in Iranian field conditions, and their F1 hybrids were used in this study. Seedlings of 36 doubled haploid lines, selected out of 96 according to their agronomic traits and the two parental genotypes were inoculated with eight races of yellow rust. The parental genotypes (‘Ghods’and‘9106’) were segregating for some of the races but their doubled haploid lines were either resistant or susceptible to them.‘Ghods’was susceptible to three of the races studied but three doubled haploid lines derived from it were resistant to them. Five selected doubled haploids from the‘9106’genotype and six from F1 hybrid plants were resistant to all eight races tested. After further investigations in Iranian field conditions it was found that some of these lines can be used as donor genotypes for resistance to yellow rust in wheat breeding programmes. Use of these genotypes should be possible if the French yellow rust races used for selection also represent the dominant races in Iran. It can be concluded that anther culture provides an efficient method for fixing genes of resistance to yellow rust and desirable doubled haploids from F1 plants can be derived. 相似文献
20.
H. Muylle J. Baert E. Van Bockstaele B. Moerkerke E. Goetghebeur I. Roldán-Ruiz 《Euphytica》2005,143(1-2):135-144
Crown rust resistance is an important selection criterion in ryegrass breeding. The fungal disease caused by P. coronata causes yield loss and a reduced quality of the fodder crop. Molecular markers were used to unravel the genomic organization of crown rust resistance in a segregating L. perenne population. Two genomic regions involved in crown rust resistance were identified that together explained 35% of the phenotypic variance present. Bulked segregant analysis in combination with AFLP markers was a suitable method to identify DNA markers associated with genomic regions of major effect. One cluster of AFLP markers explained 6.1% of the variance and mapped to linkage group 2, a genomic region known to contain crown rust resistance genes. A second cluster of AFLP markers detected a novel genomic region of major effect that explained 27.7% of the phenotypic variance in crown rust resistance. This cluster was unlinked to the cluster on linkage group 2. Divergent selections performed within the segregating F1 population on the basis of genotype and phenotype revealed that the markers associated with crown rust resistance identified in this study have potential for marker assisted selection. Selection of plants on the basis of markers was more straightforward than the selection on the basis of phenotype. 相似文献