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1.
M. Gowda    S. Roy-Barman    B. B. Chattoo 《Plant Breeding》2006,125(6):596-599
Blast, caused by Magnaporthe grisea, is the most devastating disease of rice worldwide. In this study, the main objective was to identify and map a new gene for blast resistance, in an indica rice cultivar ‘Tadukan’ against blast fungal isolate B157, using molecular tools. F2 segregating population was derived from ‘CO39’ (susceptible) and ‘Tadukan’ (resistant), and molecular mapping of the blast resistance gene was carried out using simple sequence length polymorphism (SSLP) and amplified fragment length polymorphism (AFLP) methods. Two SSLP markers, RM206 and RM21 and three AFLP markers (AF1: E‐aca/M‐ctt; AF2: E‐aca/M‐cat and AF3: E‐acc/M‐cac2) were identified to be linked to the resistance gene. The co‐segregation analysis using SSLP markers implied that the blast resistance gene designated Pi38 resides on rice chromosome 11.  相似文献   

2.
We investigated the mode of inheritance and map location of field resistance to rice blast in the elite rice strain Chubu 111, and yield under severe blast conditions. Chubu 111 carries the complete resistance gene Pii, although field testing showed this strain to be susceptible to infection. The level of field resistance of Chubu 111 was so high that chemicals used to control blast were not required, even in an epiphytotic area. Genetic analysis of field resistance to blast in 149 F3 lines derived from a cross between Chubu 111 and the susceptible cultivar ‘Mineasahi’ suggested that field resistance is controlled by a dominant gene, designated Pi39(t), that cosegregates with the single sequence repeat marker loci RM3843 and RM5473 on chromosome 4. Comparative studies of polymorphism at RM3843 among Chubu 111 and six cultivars or lines in its pedigree suggested that the donor of the resistance gene was the Chinese cultivar ‘Haonaihuan’. Marker‐assisted selection of Pi39(t) should be useful in rice‐breeding programmes for field resistance to blast.  相似文献   

3.
W. Tadesse    S. L. K. Hsam    F. J. Zeller 《Plant Breeding》2006,125(4):318-322
A total of 50 wheat (Triticum aestivum L.) cultivars were evaluated for resistance to tan spot, using Pyrenophora tritici‐repentis race 1 and race 5 isolates. The cultivars ‘Salamouni’, ‘Red Chief’, ‘Dashen’, ‘Empire’ and ‘Armada’ were resistant to isolate ASC1a (race 1), whereas 76% of the cultivars were susceptible. Chi‐squared analysis of the F2 segregation data of hybrids between 20 monosomic lines of the wheat cultivar ‘Chinese Spring’ and the resistant cultivar ‘Salamouni’ revealed that tan spot resistance in ‘Salamouni’ was controlled by a single recessive gene located on chromosome 3A. This gene is designated tsn4. The resistant cultivars identified in this study are recommended for use in breeding programmes to improve tan spot resistance in common wheat.  相似文献   

4.
Genetic basis of seedling-resistance to leaf rust in bread wheat 'Thatcher'   总被引:1,自引:0,他引:1  
A. N. Mishra    K. Kaushal    G. S. Shirsekar    S. R. Yadav    R. N. Brahma    H. N. Pandey 《Plant Breeding》2005,124(5):514-516
The bread wheat cultivar ‘Thatcher’ is documented to carry the gene Lr22b for adult‐plant resistance to leaf rust. Seedling‐resistance to leaf rust caused by Puccinia triticina in the bread wheat cultivar ‘Thatcher’, the background parent of the near‐isogenic lines for leaf rust resistance genes in wheat, is rare and no published information could be found on its genetic basis. The F2 and F3 analysis of the cross ‘Agra Local’ (susceptible) × ‘Thatcher’ showed that an apparently incompletely dominant gene conditioned seedling‐resistance in ‘Thatcher’ to the three ‘Thatcher’‐avirulent Indian leaf rust pathotypes – 0R8, 0R8‐1 and 0R9. Test of allelism revealed that this gene (temporarily designated LrKr1) was derived from ‘Kanred’, one of the parents of ‘Thatcher’. Absence of any susceptible F2 segregants in a ‘Thatcher’ × ‘Marquis’ cross confirmed that an additional gene (temporarily designated LrMq1) derived from ‘Marquis’, another parent of ‘Thatcher’, was effective against pathotype 0R9 alone. These two genes as well as a second gene in ‘Kanred’ (temporarily designated LrKr2), which was effective against all the three pathotypes, but has not been inherited by ‘Thatcher’, seem to be novel, undocumented leaf rust resistance genes.  相似文献   

5.
N. Saka    T. Tsuji    T. Toyama    M. Yano    T. Izawa    T. Sasaki 《Plant Breeding》2006,125(2):140-143
The chromosomal location of the resistance gene for green rice leafhopper (GRLH), an injurious insect for rice, has been determined and RFLP markers closely linked to this gene have been identified. The susceptible japonica rice variety ‘Nipponbare’ was crossed with a resistant japonica rice line ‘Aichi42’, in which green rice leaf hopper resistance had been introduced from an indica variety ‘Rantaj‐emas2’, and the 100 F2 plants obtained were used for linkage analysis. The green rice leafhopper resistance gene, Grh3(t), was mapped between RFLP markers C288B and C133A on chromosome 6 and co‐segregated with C81. Of the RFLP markers tightly linked to Grh3(t), C81 was converted to a SCAR marker and C133A to a cleaved amplified polymorphic sequence marker that could distinguish the heterozygous genotype to establish an effective marker‐aided selection system for the GRLH resistance gene.  相似文献   

6.
The rice cultivar ‘Chumroo’ is commonly cultivated in the mid- and high-altitude areas of Bhutan. This cultivar has shown durable blast resistance in that area, without evidence of breakdown, for over 20 years. Chumroo was inoculated with 22 blast isolates selected from the race differential standard set of Japan. The cultivar showed resistance to all the isolates. To identify the resistance gene(s), Chumroo was crossed with a susceptible rice cultivar, Koshihikari. The F1 plants of the cross showed resistance. Segregation analyses of 300 F3 family lines fitted the segregation ratio of 1:2:1 and indicated that a single dominant gene controls the resistance to a blast isolate Ao 92-06-2 (race 337.1). The Chumroo resistance locus (termed Pi46(t)) was mapped between two SSR markers, RM6748 and RM5473, on the terminal region of the long arm of chromosome 4, using linkage analysis with SSR markers. The nearest marker, RM5473, was linked to the putative resistance locus at a map distance of 3.2 cM. At the chromosomal region, no true resistance genes were identified, whereas two field resistance genes were present. Therefore, we designated Pi46(t) as a novel blast resistance locus.  相似文献   

7.
Soybean mosaic virus (SMV) can cause serious yield losses in soybean. Soybean cultivar ‘RN‐9’ is resistant to 15 of 21 SMV strains. To well‐characterize this invaluable broad‐spectrum SMV‐resistance, populations (F1, F2 and F2:3) derived from resistant (R) × susceptible (S) and R × R crosses were tested for SMV‐SC18 resistance. Genetic analysis revealed that SC18 resistance in ‘RN‐9’ plus two elite SMV‐resistant genotypes (‘Qihuang No.1’ and ‘Kefeng No.1’) are controlled by independently single dominant genes. Linkage analysis showed that the resistance of ‘RN‐9’ to SMV strains SC10, SC14, SC15 and SC18 is controlled by more than one gene(s). Moreover, Rsc10‐r and Rsc18‐r were both positioned between the two simple sequence repeats markers Satt286 and Satt277, while Rsc14‐r was fine‐mapped in 136.8‐kb genomic region containing sixteen genes, flanked by BARCSOYSSR_06_0786 and BARCSOYSSR_06_0790 at genetic distances of 3.79 and 4.14 cM, respectively. Allelic sequence comparison showed that Cytochrome P450‐encoding genes (Glyma.06g176000 and Glyma.06g176100) likely confer the resistance to SC14 in ‘RN‐9’. Our results would facilitate the breeding of broad‐spectrum and durable SMV resistance in soybeans.  相似文献   

8.
Q. H. Pan    L. Wang    H. Ikehashi    H. Yamagata  T. Tanisaka 《Plant Breeding》1998,117(1):27-31
The Chinese native rice cultivar ‘Maowangu’ expresses a high level of resistance to many races of rice blast (Pyricularia grisea) collected from North China and Japan. ‘Maowangu’ was crossed with 10 Japanese differential cultivars and the susceptible Chinese cultivar ‘Lijiangxintuanheigu’ (LTH). Allelism tests were conducted in the F2 populations with rice blast races. The resistance of ‘Maowangu’ was governed by two dominant genes which were non-allelic to the resistance genes at seven loci: Pi-a, Pi-i, Pi-k, Pi-z, Pi-ta, Pi-b, and Pi-t. To identify the two resistance genes, two F3 lines of ‘Shin 2/Maowangu’ segregating 3R:1S were selected for linkage tests in 1994. One was linked to marker genes C and Amp-3 on chromosome 6 with recombination frequencies of 35.8 ± 6.4% and 42.1 ± 6.2%, respectively, and the other to Amp-1 on chromosome 2 with a recombination frequency of 37.6 ± 6.0%. To confirm these results, two F3 lines of ‘LTH/Maowangu’ were selected for linkage tests in 1995. The one was linked to Amp-3, and other was linked to Amp-1, with recombination frequencies of 36.9 ± 3.1% and 34.3 ± 3.2%, respectively. The two genes on chromosomes 6 and 2 were designated Pi13(t) and Pi14(t), respectively.  相似文献   

9.
M. Heun  G. Fischbeck 《Plant Breeding》1989,103(3):262-264
The inheritance of the Mlk powdery mildew resistance originating from ‘Heine 2174.50’ was analyzed by crossing the Mlk resistant cultivar ‘Ralle’× cv. ‘Amor’ (highly susceptible) and vice versa and by observing the reactions of F1- and F2-plants after inoculation with two different Mlk avirulent powdery mildew isolates. In all cases, a 3 (resistant): I (susceptible) segregation was found in F2. The reactions of the F2plants against the two powdery mildew isolates were identical in each case. Therefore, it is supposed that one dominant resistant gene is responsible for the resistant reactions against these two isolates. These results support the earlier assumption of Heun and Fischbeck (1987b) that the whole Mlk resistance pattern is controlled by a single gene.  相似文献   

10.
The present work was conducted to identify microsatellite markers linked to the rice blast resistance gene Pi-1(t) for a marker-assisted selection program. Twenty-four primer pairs corresponding to 19 microsatellite loci were selected from the Gramene database (www. gramene.org) considering their relative proximity to Pi-1(t) gene in the current rice genetic map. Progenitors and DNA bulks of resistant and susceptible families from F3 segregating populations of a cross between the near-isogenic lines C101LAC (resistant) and C101A51 (susceptible) were used to identify polymorphic microsatellite markers associated to this gene through bulked segregant analysis. Putative molecular markers linked to the blast resistance gene Pi-1(t) were then used on the whole progeny for linkage analysis. Additionally, the diagnostic potential of the microsatellite markers associated to the resistance gene was also evaluated on 17 rice varieties planted in Latin America by amplification of the specific resistant alleles for the gene in each genotype. Comparing with greenhouse phenotypic evaluations for blast resistance, the usefulness of the highly linked microsatellite markers to identify resistant rice genotypes was evaluated. As expected, the phenotypic segregation in the F3 generation agreed to the expected segregation ratio for a single gene model. Of the 24 microsatellite sequences tested, six resulted polymorphic and linked to the gene. Two markers (RM1233*I and RM224) mapped in the same position (0.0 cM) with the Pi-1(t) gene. Other three markers corresponding to the same genetic locus were located at 18.5 cM above the resistance gene, while another marker was positioned at 23.8 cM below the gene. Microsatellite analysis on elite rice varieties with different genetic background showed that all known sources of blast resistance included in this study carry the specific Pi-1(t) allele. Results are discussed considering the potential utility of the microsatellite markers found, for MAS in rice breeding programs aiming at developing rice varieties with durable blast resistance based on a combination of resistance genes. Centro Internactional de Agricultura Tropical (CIAT) institute where the research was carried out  相似文献   

11.
The inheritance of resistance to green leafhopper, Nephotettix impicticeps Ichi, was studied in 11 cultivars of rice, Oryza saliva L. These resistant cultivars were crossed with the susceptible cultivar ‘TN1’. The materials consisted of F1, F2 and F3 populations including parents which were assessed by the bulk screening test. It was found that resistance in the cultivars TR36′, UPR254-35-3′-2′, ‘Jhingasail’, ‘Govind’, ‘RP825-45-1-3’, ‘MRC603-303’, ‘RD4’, and ‘Irat104 ’ was conditioned by a single dominant gene, whereas resistance in ‘Ptb8’ IR9805-97-1′, and ‘BG367-7’ was controlled by one recessive gene. The test on the allelic relationships of the resistance genes in the test cultivars with the known genes Glb1 and Glb2 revealed that the single dominant gene that conveyed the resistance in ‘UPR254-35-3-2’ and ‘Jhingasail’ was allelic to Glh1 and segregated independently of Glh2. The resistance in ‘Govind’ and ‘RP82S-45-1-3’ was governed by the Glh2 gene which was independent of Glh1. The test cultivars ‘IR36’;. ‘MRC603-303’, ‘RD4’. and Irat104 ’ had a dominant gene for resistance which was nonallelic to Glb1 and Glb2. The recessive gene which conditioned the resistance in ‘Ptb8’, ‘IR9805-97-1’, and ‘BG367-1’ segregated independently of Glh1 and Glh2. Eleven trisomics in an ‘TR36’ background were crossed with ‘Java’, a cultivar susceptible to green leafhopper. The segregation pattern of the F2 and backcross generations revealed that the Glb6 gene was located on chromosome 5.  相似文献   

12.
The Japanese barley cultivar, ‘Chikurin Ibaraki 1’, is partially resistant to the PAV serotype of barley yellow-dwarf virus (BYDV), but its induced mutant line, Ea52, is susceptible. The inheritance of resistance in cv. ‘Chikurin Ibaraki 1’ to BYDV-PAV was investigated. The F, and F2 plants of crosses of cvs ‘Chikurin Ibaraki 1’, Ea52, ‘Vixen’, carrying the Yd2 gene of resistance, and ‘Plaisant’, a susceptible French cultivar, were tested in growth chamber and field conditions. Isolate RG, against which ‘Chikurin Ibaraki 1’ is partially resistant in growth chamber and field conditions, and isolate 2t, which overcomes the partial resistance of ‘Chikurin Ibaraki 1’ in field conditions (Chalhoub et al. 1994) were used. The segregation of F2 plants of crosses between ‘Chikurin Ibaraki 1’ and the susceptible cultivars to isolate RG (one resistant to three susceptible) suggests that the resistance of ‘Chikurin Ibaraki 1’ is controlled by a single recessive gene. All 537 F2 plants of ‘Chikurin Ibaraki 1’בVixen’ tested with isolate RG in growth chamber and field conditions were resistant. The F2 plants of this cross were all resistant to isolate 2t in growth chamber conditions but segregated with a ratio of one resistant to three susceptible in field conditions owing to the susceptibility of ‘Chikurin Ibaraki 1’ to this isolate. Results suggest that the resistance gene in ‘Chikurin Ibaraki 1’ is tightly linked or allelic with the Yd2 gene in ‘Vixen’. However, it differs from this gene in ‘Vixen’ in that it can be overcome by isolate 2t in field conditions.  相似文献   

13.
A set of 21 monosomic (2n ‐ 1) and the disomic (2n) lines of the ‘Chinese Spring’ cultivar were crossed with ‘Chirya‐3′, the CIMMYT synthetic wheat line which has been identified as highly resistant for Helminthosporium leaf blight disease (HLB), in order to locate the genes governing disease resistance. The F1 and segregating populations were challenged and screened against the most virulent pure mono‐conidial HLB isolate KL‐8 (Karnal, India). The F1 progenies of the crosses were found to be susceptible because of the recessive nature of resistance. The F2 progeny of the control cross (‘Chinese Spring’בChirya‐3’), segregated in the ratio of 1: 15 (resistant: susceptible), indicating that resistance to HLB was controlled by a pair of recessive genes. While the F2 progeny of 19 monosomic crosses segregated in the ratio of 1: 15 (resistant: susceptible), the progeny of the remaining two crosses, 7B and 7D, deviated significantly from the ratio, revealing that 7B and 7D were the critical chromosomes for resistance genes that were located one on each chromosome. Moreover, the critical lines, 7B and 7D, confirmed the digenic complementary recessive nature of gene action by fitting well with the overall pooled F2 segregation ratio of 13: 51 (resistant: susceptible) as expected for digenic complementary recessive resistance. The F3 segregation ratios of the critical crosses, based on their pooled F2 analysis, was estimated as 19: 32: 13 (non‐segregating susceptible: segregating as susceptible and resistant: non‐segregating resistant). F3 progenies when tested with these ratios showed goodness‐of‐fit, confirming that the two pairs of recessive resistance genes were located on chromosomes 7B and 7D.  相似文献   

14.
M. T. Assad 《Plant Breeding》2002,121(2):180-181
The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), is a major economic pest of small grains in many countries. An experiment was therefore conducted to determine the inheritance of gene(s) controlling resistance to RWA in a resistant tetraploid durum wheat line. This resistant line,‘1881′, was crossed to a susceptible line, ‘Orejy‐e‐Kazeroon’, and then F1 F2 and BCF1 (backcross to susceptible line) seedlings were screened in a greenhouse for RWA resistance following artificial infection. Resistance in ‘1881’ was apparently controlled by one dominant gene. Since Dnl, Dn2, dn3, Dn4 and Dn5 have been reported to be located on genome D, it was reasoned that the resistance gene in ‘1881’ is not allelic to them.  相似文献   

15.
Wheat blast disease, caused by Magnaporthe oryzae (anamorph Pyricularia oryzae), produces severe damage to wheat production in South America. It was observed that many resistant cultivars contain the 2NS/2AS translocation from Triticum ventricosum. In this study, we evaluate the presence of the 2NS/2AS translocation in 57 advanced breeding lines and one variety ‘Caninde 1’ from Paraguayan wheat germplasm, using VENTRIUP‐LN2 primers. The germplasm ‘Caninde 1 and 22’ of the breeding lines, found positive for the presence of 2NS/2AS translocation, were inoculated with a single aggressive Magnaporthe pathotype P14‐039, to assess their response to wheat blast infection under controlled conditions. Based on the disease infection score, ten of the breeding lines, ‘Caninde 1’ and ‘Milan’ (positive control), were classified as resistant. Three of the remaining breeding lines were classified as moderately resistant, five as moderately susceptible and other four as susceptible. Our results show that the expression of 2NS/2AS‐based blast resistance is more dependent on genetic background of the inserted germplasm than previously envisioned.  相似文献   

16.
Amplified fragment length polymorphism (AFLP) and microsatellite (simple sequence repeat, SSR) techniques were used to map the _RGSpeking gene, which is resistant to most isolates of Cercospora sojina in the soya bean cultivar ‘Peking’. The mapping was conducted using a defined F2 population derived from the cross of ‘Peking’(resistant) בLee’(susceptible). Of 64 EcoRI and MseI primer combinations, 30 produced polymorphisms between the two parents. The F2 population, consisting of 116 individuals, was screened with the 30 AFLP primer pairs and three mapped SSR markers to detect markers possibly linked to RcsPeking. One AFLP marker amplified by primer pair E‐AAC/M‐CTA and one SSR marker Satt244 were identified to be linked to ResPeking. The gene was located within a 2.1‐cM interval between markers AACCTA178 and Satt244, 1.1 cM from Satt244 and 1.0 cM from AACCTA178. Since the SSR markers Satt244 and Satt431 have been mapped to molecular linkage group (LG) J of soya bean, the ResPeking resistance gene was putatively located on the LG J. This will provide soya bean breeders an opportunity to use these markers for marker‐assisted selection for frogeye leaf spot resistance in soya bean.  相似文献   

17.
An F8 recombinant inbred population was constructed using a commercial indica rice variety Zhong 156 as the female parent and a semidwarf indica variety Gumei 2 with durable resistance to rice blast as the male parent. Zhong 156 is resistant to the fungus race ZC15 at the seedling stage but susceptible to the same race at the flowering stage. Gumei 2 is resistant to ZC15 at both stages. The blast resistance of 148 recombinant inbred lines was evaluated using the blast race ZC15. Genetic analysis indicated that the resistance to leaf blast was controlled by three genes and the presence of resistant alleles at any loci would result in resistance. One of the three genes did not have effects at the flowering stage. Two genes, tentatively assigned as Pi24(t) and Pi25(t), were mapped onto chromosome 12 and 6,respectively, based on RGA (resistance gene analog), RFLP and RAPD markers. Pi24(t) conferred resistance to leaf blast only, and its resistance allele was from Zhong 156. Pi25(t) conferred resistance to both leaf and neck blast, and its resistance allele was from Gumei 2. In a natural infection test in a blast hot-spot, Pi25(t) exhibited high resistance to neck blast, while Pi24(t) showed little effect. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

18.
Several R2 somaclonal families were derived from plants regenerated from a salt‐resistant callus of the salt‐sensitive rice cultivar ‘I Kong Pao’ (IKP). The family R2‐1‐23, in the presence of NaCl exhibited higher yield performances than the initial cultivar. This improvement in salinity resistance, however, was not transmitted to following generations; despite a higher number of spikelets per plant, family R3‐1‐23 did not perform better than the initial cultivar because of a very low seed set. This somaclonal family, its initial being the cultivar IKP, the breeding line IR31785 (extremely salt‐sensitive) and the cultivar ‘Aiwu’ (moderately salt‐resistant), were used as parents for production ofhybrids. Four crosses, IKP×R3‐1‐23, IR31785 ×R3‐1‐23, IR31785× IKP and IKP בAiwu’, were performed. Most of the F1 hybrids cultivated in the absence of salt exhibited increased performances compared with the mid‐parent, suggesting an heterosis effect for yield‐related parameters. F2 populations were screened for salinity resistance and a clear improvement for yield in stress conditions was recorded for populations derived from IK×R3‐1‐23, IR31785×R3‐1‐23 and IR31785×IKP, although the mean level of increase over the mid‐parent (RIMP) varied depending on the population, the presence or absence of stress, and the quantified parameters. The results are discussed in relation to the usefulness of in vitro selection for obtaining interesting somaclonal variants useful to be integrated in classical breeding programmes for salinity resistance in rice.  相似文献   

19.
One of the most important diseases of barley (Hordeum vulgare) is powdery mildew, caused by Blumeria graminis f. sp. hordei. Spring barley line 173-1-2 was selected from a Moroccan landrace and revealed broad-spectrum resistance to powdery mildew. The objective of this study was to map and characterize the gene for seedling powdery mildew resistance in this line. After crossing with the susceptible cultivar ‘Manchuria’, genetic analysis of F2 and F3 families at the seedling stage revealed powdery mildew resistance in line 173-1-2 conditioned by a single recessive gene. Molecular analysis of non-segregating homozygous resistant and homozygous susceptible F2 plants conducted on the DArTseq platform (Diversity Arrays Technology Pty Ltd) identified significant markers which were converted to allele-specific PCR markers and tested among 94 F2 individuals. The new resistance gene was mapped on the long arm of chromosome 6H. No other powdery mildew recessive resistance gene has been located on 6H so far. Therefore, we concluded that the 173-1-2 barley line carries a novel recessive resistance gene designated as mlmr.  相似文献   

20.
A population of 108 common bean recombinant inbred lines (RILs) (F5:6‐9), derived from a leafhopper (Empoasca fabae and E. kraemeri)‐susceptible cultivar (‘Berna’) and a leafhopper‐resistant line (EMP 419) was used to identify molecular markers genetically linked to leafhopper resistance and seed weight. Bulked segregant analysis and quantitative trait analysis identified eight markers that were associated with resistance to E. fabae, and four markers that were associated with E. kraemeri resistance. Three markers were associated with resistance to both species. A partial linkage map of the bean genome was constructed. Composite interval mapping identified quantitative trait loci (QTL) for resistance to both leaf hopper species on core‐map linkage groups B1, B3 and B7. QTL for seed weight were found close to the locus controlling testa colour and an α‐phaseolin gene.  相似文献   

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