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1.
The genetics of resistance to Ascochyta blight (Ascochyta fabae f. sp. fabae) was studied in two populations of faba bean (Vicia faba). Plants of a resistant population, ILB 752, and a susceptible one, NEB 463, were screened for their reaction to the pathogen and the results were quantified on a scale of 0–5. Crosses were made between plants both within and between accessions and the F1 and F2 generations assessed in a field trial 21 and 45 days after inoculation. Disease scores were greater at 45 days than at 21 days and they were not significantly affected by the presence of susceptible spreader rows in part of the trial. ILB 752 carried a major dominant gene conferring resistance while NEB 463 carried the recessive allele for susceptibility. Furthermore, a minority of plants of NEB 463 appeared to carry at least one pair of complementary recessive genes, also conferring resistance. Most of the plants of ILB 752 were homozygous for the dominant resistance gene and a few were heterozygous. Reciprocal crosses behaved identically, indicating the absence of maternal effects in the expression of Ascochyta blight resistance in faba beans. The results show that it is important to confirm the level of heterozygosity for the resistance genes in this partially outbreeding species before crossing is commenced. The major dominant gene for resistance, identified in ILB 752, has clear potential for use in breeding for Ascochyta blight resistance. The minor genes identified in NEB 463 also show the potential for accumulating resistance through mass selection. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

2.
Breeding for resistance to lentil Ascochyta blight   总被引:1,自引:0,他引:1  
G. Ye    D. L. McNeil  G. D. Hill 《Plant Breeding》2002,121(3):185-191
Ascochyta blight, caused by Ascochyta lentis, is one of the most globally important diseases of lentil. Breeding for host resistance has been suggested as an efficient means to control this disease. This paper summarizes existing studies of the characteristics and control of Ascochyta blight in lentil, genetics of resistance to Ascochyta blight and genetic variations among pathogen populations (isolates). Breeding methods for control of the disease are discussed. Six pathotypes of A. lentis have been reported. Many resistant cultivars/lines have been identified in both cultivated and wild lentil. Resistance to Ascochyta blight in lentil is mainly under the control of major genes, but minor genes also play a role. Current breeding programmes are based on crossing resistant and high‐yielding cultivars and multilocation testing. Gene pyramiding, exploring slow blighting and partial resistance, and using genes present in wild relatives will be the methods used in the future. Identification of more sources of resistance genes, good characterization of the host‐pathogen system, and identification of molecular markers tightly linked to resistance genes are suggested as the key areas for future study.  相似文献   

3.
Summary Inheritance of resistance to the Punjab isolate of Xanthomonas campestris pv. oryzae of bacterial blight disease of rice was studied in seven breeding lines resistant to the disease. The results revealed that resistance in breeding lines PAU 122-73-1-4-1, PAU 164-102-1-2-1-1-1, KJT 24, IR 5657-33-2-1-2 and IR 22082-41-2-2 was controlled by single dominant genes allelic to the dominant gene which confers resistance to the Punjab isolate in Patong 32. Resistance to the Punjab isolate in breeding lines IET 7172 and RP 2151-40-1 was found to be controlled by single recessive resistance genes allelic to one of the recessive resistance genes present in BJ 1. The two genes are independently inherited and are being used to develop bacterial blight resistant varieties.  相似文献   

4.
Summary The extreme resistance to ryegrass mosaic virus (RMV) of a clone of Lolium perenne L. was due to a combination of two distinct types of resistance: resistance to infection and resistance to multiplication and movement of virus within the plant. Resistance to infection was quantitatively inherited and highly effective against three strains of RMV, while resistance to multiplication and movement was controlled by two complementary recessive genes and was effective against only two of the three RMV strains.  相似文献   

5.
Summary Genetics of resistance to Ascochyta fabae Speg. in Vicia faba L. was studied with a final objective to develop resistant faba bean varieties to Ascochyta blight. The study was conducted separately on 3 single spore isolates (AF10-2 and AF13-2 from Tunisia and AF4-3 from France) and belonging to different groups of virulence (GV1 and GV2). Important general combining ability (GCA) effects were found especially with isolates AF10-2 and AF4-3. Specific combining ability (SCA), although significant for the 3 isolates, was important only with AF13 -2, but less important than GCA. Additive gene effects were predominant to non-additive effects. Lines 29H and A8817 transmitted to their progenies resistance to the 3 isolates, whereas 14–12 and 19TB conferred resistance to their progenies only with isolates AF13-2 and AF4-3, respectively. In the material studied, resistance was generally controlled by dominant genes but also could be attributed to recessive genes although less frequent. Analysis of segregation in the F2 of 2 crosses between the resistant lines (A8817 and 29H) and the susceptible line (14–12) with isolate AF4-3 revealed dominant monogenic control at the level of leaves in the 2 resistant lines and, in addition, a recessive gene controlling resistance of stems. Non-allelic interactions were occasionally manifested and their origin appeared to be due to line 19TB. A recurrent selection scheme was proposed with the objective to develop improved open-pollination populations and synthetic varieties responding to the objective of the national Tunisian research programme on faba bean.  相似文献   

6.
Summary Six chickpea lines resistant to Ascochyta rabiei (Pass.) Lab. were crossed to four susceptible cultivars. The hybrids were resistant in all the crosses except the crosses where resistant line BRG 8 was involved. Segregation pattern for diseases reaction in F2, BCP1, BCP2 and F3 generations in field and glasshouse conditions revealed that resistance to Ascochyta blight is under the control of a single dominant gene in EC 26446, PG 82-1, P 919, P 1252-1 and NEC 2451 while a recessive gene is responsible in BRG 8. Allelic tests indicated the presence of three independently segregating genes for resistance; one dominant gene in P 1215-1 and one in EC 26446 and PG 82-1, and a recessive one in BRG 8.Research paper No. 3600  相似文献   

7.
Summary The mode of inheritance of resistance to Ascochyta blight (Ascochyta rabiei) isolate G-52 in chickpea was studied in three cross combinations and their reciprocals. It was found that resistance variety I-13 was controlled by a single dominant gene pair.  相似文献   

8.
Ascochyta blight is a devastating disease of chickpea. Breeders have been trying to introduce resistance from wild Cicer into cultivated chickpea, however, the effort is hampered by the frequent genetic drag of undesirable traits. Therefore, this study was aimed to identify potential markers linked to plant growth habit, ascochyta blight resistance and days to flowering for marker-assisted breeding. An interspecific F2 population between chickpea and C. reticulatum was constructed to develop a genetic linkage map. F2 plants were cloned through stem cuttings for replicated assessment of ascochyta blight resistance. A closely linked marker (TA34) on linkage group (LG) 3 was identified for plant growth habit explaining 95.2% of the variation. Three quantitative trait loci (QTLs) explaining approximately 49% of the phenotypic variation were found for ascochyta blight resistance on LG 3 and LG 4. Flowering time was controlled by two QTLs on LG3 explaining 90.2% of the variation. Ascochyta blight resistance was negatively correlated with flowering time (r = −0.22, P < 0.001) but not correlated with plant growth habit.  相似文献   

9.
J. Cotten  J. D. Hayes 《Euphytica》1972,21(3):538-542
Summary Genetic analysis of cereal cyst nematode resistance in three genotypes of oats indicates that resistance in Avena sterilis I.376 is controlled by two dominant genes and in A. sativa cv. Mortgage Lifter by two recessive genes. Resistance in A. byzantina P.I. 175021 is dominant and monogenic, and is probably at a locus distinct from the resistance loci in the other two genotypes.  相似文献   

10.
S. K. Dey  Gurdip Singh 《Euphytica》1993,68(1-2):147-153
Summary Genetic regulation of host resistance in chickpea-Ascochyta rabiei interaction system is governed by two dominant complementary genes each in the genotypes GLG 84038 and GL 84099, whereas the resistance in a black seeded genotype ICC 1468 was controlled by one dominant and one recessive independent gene. In all the genotypes, resistance is operated by inter-allelic interactions. The genes conferring resistance in GLG 84038 were found to be different to those operating in GL 84099 and ICC 1468. Among the five dominant genes dispersed in 3 genotypes under study, at least one has been reported for the first time, as to date, only three dominant genes have been reported in the literature.The four identified dominant genes in GLG 84038 and GL 84099 have been named as Arc1, Arc2 (in GLG 84038) and Arc3, Arc4 (in GL 84099). The undistinguished dominant gene in ICC 1468 has been named as Arc5(3,4) as it could not be equated or differentiated from Arc3 or Arc4. The recessive gene in ICC 1468 has been named as Arc1.Generation mean analysis of the 6 resistant × susceptible crosses involving the same genotypes, revealed that the genes conferring resistance in any of the 3 genotypes did not follow simple Mendelian inheritance but were influenced by inter allelic interactions. Additive gene effect along with dominance were operative in all the 3 genotypes under study in conferring resistance. However, the mechanism of resistance in GLG 84038 and GL 84099 were primarily additive in nature while that in ICC 1468, dominance as well as dominance × dominance interactions were more important than additive gene action.  相似文献   

11.
A study was conducted under controlled environment conditions in a phytotron to determine the nature of the inheritance of resistance Helminthosporium leaf blight (HLB) in a synthetic hexaploid wheat line, ‘Chirya‐3’, against the isolate KL‐8 of Bipolaris sorokiniana from the major wheat growing region of India. Crosses were made between two susceptible lines ‘WH 147’ and ‘Chinese Spring’. Analyses of F1 and F2 populations of these two crosses (‘WH 147’בChirya‐3’ and ‘Chinese Spring’בChirya‐3’) showed that resistance against the isolate in ‘Chirya‐3’ was governed by two recessive genes functioning in a complementary interaction giving an F2 segregation pattern of 1 : 15 (resistant : susceptible). The segregation pattern of the resistant F2 progenies in F3 families from both crosses confirmed that two homozygous recessive genes were responsible for resistance to the isolate of Bipolaris sorokiniana in the synthetic line ‘Chirya‐3’. It is proposed that the genes be designated as hlbr1 and hlbr2.  相似文献   

12.
Genetics of resistance to ascochyta blight was studied using different generations of fifteen crosses of chickpea (Cicer arietinum L.). Six parents comprising two susceptible varieties GL 769, C 214 and four resistant lines GG 1267, GL 90168, GL 96010 and GL 98010 were used to develop one S × S, eight S × R and six R × R crosses and some of the back crosses and F3 generations were developed. Field screening technique was used to evaluate the different generations for disease reaction using mixture of ten prevalent isolates (ab1–ab10) of ascochyta blight (Ascochyta rabiei). Inheritance study showed digenic recessive control of resistance in the cross GL 769 × C 214, whereas monogenic recessive control of resistance was found in the crosses GL 769 × GL 98010 and C 214 × GL 98010. Digenic dominant and recessive control of resistance was found in the crosses GL 769 × GG 1267 and C 214 × GG 1267 while the crosses GL 769 × GL 90168 and C 214 × GL 96010 showed the monogenic dominant control of resistance. Trigenic dominant and recessive control of resistance was observed in the crosses GL 769 × GL 96010 and C 214 × GL 90168. Allelic relationship studies showed that three resistant parents viz., GG 1267, GL 96010 and GL 90168 possessed allelic single dominant gene for resistance. Besides, GG 1267 possessed two minor recessive genes for resistance, one of them was allelic to the minor recessive gene possessed by GL 90168 and other with GL 96010. The resistant parents GL 90168 and GL 96010 possessed non-allelic minor gene for resistance. The resistant parent GL 98010 possessed two minor recessive genes for resistance which were allelic to respective single recessive gene for resistance possessed by the susceptible parents GL 769 and C 214. The susceptible parents GL 769 and C 214 also possessed single independent inhibitory dominant susceptibility gene. The inhibitory gene was epistatic to the corresponding recessive gene for resistance.  相似文献   

13.
Ascochyta blight caused by the fungus Ascochyta lentis Vassilievsky and anthracnose caused by Colletotrichum truncatum [(Schwein.) Andrus & W.D. Moore] are the most destructive diseases of lentil in Canada. The diseases reduce both seed yield and seed quality. Previous studies demonstrated that two genes, ral1 and AbR1, confer resistance toA. lentis and a major gene controls the resistance to 95B36 isolate of C. truncatum. Molecular markers linked to each gene have been identified. The current study was conducted to pyramid the two genes for resistance to ascochyta blight and the gene for resistance to anthracnose into lentil breeding lines. A population (F6:7) consisting of 156 recombinant inbred lines (RILs) was developed from across between ‘CDC Robin’ and a breeding line ‘964a-46’. The RILs were screened for reaction to two isolates (A1 and 3D2) ofA. lentis and one isolate (95B36) ofC. truncatum. χ2 analysis of disease reactions demonstrated that the observed segregation ratios of resistant versus susceptible fit the two gene model for resistance to ascochyta blight and a single gene model for resistance to anthracnose. Using markers linked to ral1 (UBC 2271290), to AbR1(RB18680) and to the major gene for resistance to anthracnose (OPO61250),respectively, we confirmed that 11 RILs retained all the three resistance genes. More than 82% of the lines that had either or both RB18680 and UBC2271290markers were resistant to 3D2 isolate and had a mean disease score lower than 2.5. By contrast, 80% of the lines that had none of the RAPD markers were susceptible and had a mean disease score of 5.8. For the case of A1 isolate of A. lentis, more than 74% of the lines that carriedUBC2271290 were resistant, whereas more than 79% of the lines that do not have the marker were susceptible. The analysis of the RILs usingOPO61250 marker demonstrated that 11out of 72 resistant lines carried the marker, whereas 66 out of 84 susceptible lines had the marker present. Therefore, selecting materials with both markers for resistance to ascochyta blight and a marker for resistance to anthracnose can clearly make progress toward resistance in the population. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

14.
RAPD and SCAR markers for resistance to acochyta blight in lentil   总被引:3,自引:0,他引:3  
Resistance to ascochyta blight of lentil (Lens culinaris Medikus),caused by the fungus Ascochyta lentis, is determined by a single recessive gene, ral 2, in the lentil cultivar Indian head. Sixty F2 individuals from a cross between Eston (susceptible) and Indian head (resistant) lentil were analyzed for the presence of random amplified polymorphic DNA (RAPD) markers linked to the ral 2gene, using bulked segregant analysis (BSA). Out of 800 decanucleotide primers screened, two produced polymorphic markers that co-segregated with the resistance locus. These two RAPD markers, UBC2271290and OPD-10870, flanked and were linked in repulsion phase to the gene ral 2 at 12 cm and 16 cm, respectively. The RAPD fragments were converted to SCAR markers. The SCAR marker developed from UBC2271290 could not detect any polymorphism between the two parents or in the F2. The SCAR marker developed from OPD-10870 retained its polymorphism. The polymorphic RAPD marker UBC2271290 and the SCAR marker developed from OPD-10870 can be used together in a marker assisted selection program for ascochyta blight resistance in lentil. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

15.
Ascochyta blight is a major fungal disease affecting chickpea production worldwide. The genetics of ascochyta blight resistance was studied in five 5 × 5 half-diallel cross sets involving seven genotypes of chickpea (ICC 3996, Almaz, Lasseter, Kaniva, 24B-Isoline, IG 9337 and Kimberley Large), three accessions of Cicer reticulatum (ILWC 118, ILWC 139 and ILWC 184) and one accession of C. echinospermum (ILWC 181) under field conditions. Both F1 and F2 generations were used in the diallel analysis. The disease was rated in the field using a 1–9 scale. Almaz, ICC 3996 and ILWC 118 were the most resistant (rated 3–4) and all other genotypes were susceptible (rated 6–9) to ascochyta blight. Estimates of genetic parameters, following Hayman’s method, showed significant additive and dominant gene actions. The analysis also revealed the involvement of both major and minor genes. Susceptibility was dominant over resistance to ascochyta blight. The recessive alleles were concentrated in the two resistant chickpea parents ICC 3996 and Almaz, and one C. reticulatum genotype ILWC 118. The wild Cicer accessions may have different major or minor resistant genes compared to the cultivated chickpea. High narrow-sense heritability (ranging from 82% to 86% for F1 generations, and 43% to 63% for F2 generations) indicates that additive gene effects were more important than non-additive gene effects in the inheritance of the trait and greater genetic gain can be achieved in the breeding of resistant chickpea cultivars by using carefully selected parental genotypes.  相似文献   

16.
Ascochyta blight (AB) disease, caused by the fungus Ascochyta rabiei, is a major yield limiting factor of chickpea in Australia and around the world. The aggressiveness of six A. rabiei isolates was identified using 3 chickpea varieties (Jimbour, Flipper and Yorker). These AB isolates were isolated from chickpea fields in northern NSW, one of the major chickpea production regions in Australia. Each of the six isolates produced a different aggressiveness pattern and isolate 4859 was found to be the most aggressive. The AB resistance in 16 international and Australian chickpea genotypes was then investigated by inoculating the plants with the most aggressive isolate and a mixture of the other 5 isolates. Resistance to both the most aggressive isolate and the mixed isolates has been identified in 5 genotypes (ICCV 98813, Flipper, ICCV 05111, ICCV 98801, Jimbour #1) while 10 entries (Howzat, ICCV 06108 and ICCV 98818, Jimbour, ICCV 96852, ICCV 06107, ICCV 98816, Yorker, FLIP97-114C, ICCV 96853) were moderately resistant. Only one genotype (Bumper) appeared to be susceptible to both inoculums. There was large variation observed in the pathogenicity of the isolates suggesting that the six AB isolates represent several different pathogen strains. Significant differences in leaf infection rate, plant infection rate, plant death rate and disease development were identified among the chickpea genotypes tested. These findings suggest that these chickpea genotypes carry different resistant genes, which can be exploited in breeding programmes to develop high levels of disease resistance.  相似文献   

17.
The three major leaf types in chickpea are normal compound leaf, simple leaf and multipinnate. Simple leaf types are less commonly cultivated worldwide and are often reputed to be susceptible to ascochyta blight disease, whereas other leaf types range from resistant to susceptible. This study determined the association between host plant resistance to ascochyta blight and different leaf types in segregating populations derived from crosses between disease resistant and susceptible chickpea genotypes. In addition, the inheritance of disease resistance and leaf type was investigated in intraspecific progeny derived from crosses between two resistant genotypes with normal leaf type (ICC 3996 and Almaz), one susceptible simple leaf type (Kimberley Large) and one susceptible multipinnate leaf type (24 B-Isoline). Our results showed that, in these segregating populations, susceptibility to ascochyta blight was not linked to multipinnate or simple leaf types; resistance to ascochyta blight depended more on genetic background than leaf shape; leaf type was controlled by two genes with a dihybrid supplementary gene action; normal leaf type was dominant over other leaf types; and inheritance of ascochyta blight resistance was controlled by two major genes, one dominant and one recessive. Since there was no linkage between ascochyta blight susceptibility and leaf type, breeding various leaf types with ascochyta blight resistance is a clear possibility. These results have significant implications for chickpea improvement, as most current extra large seeded kabuli varieties have a simple leaf type.  相似文献   

18.
Summary The inheritance of resistance to white-backed planthopper, Sogatella furcifera Horvath, was investigated in a rice, Oryza sativa L., cultivar N22. Resistance to the white-backed planthopper in the cross IR30×N22 appears to be governed by a single dominant gene-designated Wbph. The classification for various characteristics of 397 F3 families of the IR30×N22 cross confirmed earlier results about the monogenic dominant control of resistance to brown planthopper, green leafhopper, and bacterial leaf blight, and about the monogenic recessive control of short stature. Additionally, the genes governing plant height and resistance to white-backed planthopper, brown planthopper, green leafhopper, and bacterial leaf blight were found to segregate independently of each other in these 397 F3 families.  相似文献   

19.
Inheritance of resistance to four Philippine races of bacterial Might caused by Xanthomonas campestris pv. oryzae was investigated in four cultivars of rice, Oryza sativa L. Resistance to three races in ‘Benamuri’ and ‘Aus 192’ is governed by xa-5. In ‘Tepal Boro’ and ‘Bazail 975′, resistance to races 1, 2. and 3 is conferred by xa-5, but another recessive gene confers resistance to race 4. This recessive gene is closely linked to xa-5 and may be allelic to xa-13. Rice cultivars with xa-13 are resistant to prevalent races of bacteria] blight in the Indian subcontinent and should thus prove useful as donors for resistance to bacterial blight in rice breeding programs.  相似文献   

20.
Summary None of the tested cultivars of lettuce was found resistant to Stemphylium leaf spot, a common disease in Israel. Within a Lactuca saligna population collected in wild lettuce in Israel, resistance was traced. Interspecific crosses of L. saligna x L. sativa were made and the mode of inheritance of resistance to this disease was studied. Resistance is apparently controlled by two genes: one dominant (Sm1) and one recessive (sm2).Contribution No. 1176-E 1984 series, from the ARO.  相似文献   

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