Pub Date : 1999-09-01DOI: 10.1080/07060669909501193
M. Smither-Kopperl, R. Charudattan, R. Berger
Fusarium culmorum is a pathogen of the submerged aquatic weed Hydrilla verticillata. The deposition and attachment of macroconidia and chlamydospores of F. culmorum in water was investigated using assays with glass slides and hydrilla shoots. The number of spores deposited on leaves along the length of hydrilla shoots in test tubes did not vary significantly with depth. Macroconidia and chlamydospores deposited on the leaf did not become attached to the surface for several hours. Two-week-old macroconidia required 3 h for attachment and 6-week-old chlamydospores required 7 h. Pretreatment of macroconidia in hydrilla extract induced production of an adhesive substance from the tips of the macroconidia, which attached to glass slides and hydrilla leaves. The adhesive substance was induced after incubation for l min in hydrilla extract, and the adhesive capacity declined after 20 min of incubation. Macroconidia that adhered to glass slides began to break free after 3 h. Co-incubation of macroconidia in hydri...
{"title":"Deposition and adhesion of spores of Fusarium culmorum on hydrilla.","authors":"M. Smither-Kopperl, R. Charudattan, R. Berger","doi":"10.1080/07060669909501193","DOIUrl":"https://doi.org/10.1080/07060669909501193","url":null,"abstract":"Fusarium culmorum is a pathogen of the submerged aquatic weed Hydrilla verticillata. The deposition and attachment of macroconidia and chlamydospores of F. culmorum in water was investigated using assays with glass slides and hydrilla shoots. The number of spores deposited on leaves along the length of hydrilla shoots in test tubes did not vary significantly with depth. Macroconidia and chlamydospores deposited on the leaf did not become attached to the surface for several hours. Two-week-old macroconidia required 3 h for attachment and 6-week-old chlamydospores required 7 h. Pretreatment of macroconidia in hydrilla extract induced production of an adhesive substance from the tips of the macroconidia, which attached to glass slides and hydrilla leaves. The adhesive substance was induced after incubation for l min in hydrilla extract, and the adhesive capacity declined after 20 min of incubation. Macroconidia that adhered to glass slides began to break free after 3 h. Co-incubation of macroconidia in hydri...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83507600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-09-01DOI: 10.1080/07060669909501185
B. Brodie
Potato cyst (Globodera spp.), root-knot (Meloidogyne spp.), and root lesion (Pratylenchus spp.) nematodes are the most economically important nematodes of potatoes in temperate climates. Potato cyst nematodes occur worldwide and include two species, Globodera pallida (the white cyst nematode) and Globodera rostochiensis (the golden nematode), each composed of several pathotypes. The gene H1 which confers a high level of resistance to the golden nematode pathotype Rol, has been bred into several potato cultivars that are grown worldwide. Mapping of the H) gene has led to the development of a molecular marker to screen segregating populations for resistance to the golden nematode and to monitor the use of resistant cultivars in statutory control programs. Pathotype Ro2 of the golden nematode that overcomes H1-mediated resistance was recently discovered in New York State in the United States, and a high level of resistance to this pathotype has been identified. Several sources of resistance to G. pallida are...
{"title":"Classical and molecular approaches for managing nematodes affecting potato","authors":"B. Brodie","doi":"10.1080/07060669909501185","DOIUrl":"https://doi.org/10.1080/07060669909501185","url":null,"abstract":"Potato cyst (Globodera spp.), root-knot (Meloidogyne spp.), and root lesion (Pratylenchus spp.) nematodes are the most economically important nematodes of potatoes in temperate climates. Potato cyst nematodes occur worldwide and include two species, Globodera pallida (the white cyst nematode) and Globodera rostochiensis (the golden nematode), each composed of several pathotypes. The gene H1 which confers a high level of resistance to the golden nematode pathotype Rol, has been bred into several potato cultivars that are grown worldwide. Mapping of the H) gene has led to the development of a molecular marker to screen segregating populations for resistance to the golden nematode and to monitor the use of resistant cultivars in statutory control programs. Pathotype Ro2 of the golden nematode that overcomes H1-mediated resistance was recently discovered in New York State in the United States, and a high level of resistance to this pathotype has been identified. Several sources of resistance to G. pallida are...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79701793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-09-01DOI: 10.1080/07060669909501195
H. W. Platt
Hypersensitive response symptoms of late blight were induced when sporangia of Phytophthora infestans were inoculated on discs of excised leaf tissues of black nightshade, eggplant, green pepper, and tobacco. No symptoms due to disease or hypersensitive response were observed in stem piece tissues of these plant species, suggesting that these four are nonhosts for late blight. The Al (US-1), the A2 (US-8), and the more recent Al mating type (US-ll) strains infected both leaf and stem tissues of climbing and hairy nightshade, potato, and tomato but only leaf tissues of petunia. This is the first report of the new strains of P. infestans causing late blight symptoms on climbing nightshade and petunia in Canada. Based on infection levels, infection rates, and spore production, the US-8 and US-ll genotypes were similar and both were more aggressive than the US-1 genotype. Disease severity and sporulation were greater on potato inoculated with US-1 than for the other host plants and were the least on petunia. ...
{"title":"Response of solanaceous cultivated plants and weed species to inoculation with A1 or A2 mating type strains of Phytophthora infestans","authors":"H. W. Platt","doi":"10.1080/07060669909501195","DOIUrl":"https://doi.org/10.1080/07060669909501195","url":null,"abstract":"Hypersensitive response symptoms of late blight were induced when sporangia of Phytophthora infestans were inoculated on discs of excised leaf tissues of black nightshade, eggplant, green pepper, and tobacco. No symptoms due to disease or hypersensitive response were observed in stem piece tissues of these plant species, suggesting that these four are nonhosts for late blight. The Al (US-1), the A2 (US-8), and the more recent Al mating type (US-ll) strains infected both leaf and stem tissues of climbing and hairy nightshade, potato, and tomato but only leaf tissues of petunia. This is the first report of the new strains of P. infestans causing late blight symptoms on climbing nightshade and petunia in Canada. Based on infection levels, infection rates, and spore production, the US-8 and US-ll genotypes were similar and both were more aggressive than the US-1 genotype. Disease severity and sporulation were greater on potato inoculated with US-1 than for the other host plants and were the least on petunia. ...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91459226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-09-01DOI: 10.1080/07060669909501183
A. Murphy, H. Jong, K. Proudfoot
Genetic plant resistance is one strategy for minimizing the effects of disease. Identification and improvements in inherent resistance have been longstanding objectives of Agriculture and Agri-Food Canada's potato breeding program at Fredericton. The potato as known in North America is a tetraploid, vegetatively propagated crop that is susceptible to a wide range of diseases and pests. Disease resistance is one of many attributes, including adaptation, consumer quality, and appearance, that must be combined in a new cultivar before it is accepted and grown on any scale. Classical breeding programs have sought and transferred sources of resistance from cultivated and wild relatives of the potato. This paper describes the approaches, the methods, and some of the hurdles encountered in the process. The example of clone F87084, which has resistances to several different diseases, will be used to portray the cooperative efforts that will culminate in this selection's release as adapted, disease-resistant germp...
{"title":"A multiple disease resistant potato clone developed with classical breeding methodology","authors":"A. Murphy, H. Jong, K. Proudfoot","doi":"10.1080/07060669909501183","DOIUrl":"https://doi.org/10.1080/07060669909501183","url":null,"abstract":"Genetic plant resistance is one strategy for minimizing the effects of disease. Identification and improvements in inherent resistance have been longstanding objectives of Agriculture and Agri-Food Canada's potato breeding program at Fredericton. The potato as known in North America is a tetraploid, vegetatively propagated crop that is susceptible to a wide range of diseases and pests. Disease resistance is one of many attributes, including adaptation, consumer quality, and appearance, that must be combined in a new cultivar before it is accepted and grown on any scale. Classical breeding programs have sought and transferred sources of resistance from cultivated and wild relatives of the potato. This paper describes the approaches, the methods, and some of the hurdles encountered in the process. The example of clone F87084, which has resistances to several different diseases, will be used to portray the cooperative efforts that will culminate in this selection's release as adapted, disease-resistant germp...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75160734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-06-01DOI: 10.1080/07060669909501208
L. Duczek, K. Sutherland, S. Reed, K. Bailey, G. Lafond
Pycnidia of Stagonospora nodorum, and pseudothecia of Phaeosphaeria nodorum and Pyrenophora triticirepentis occurred in greater numbers after one overwintering period on residues of wheat and barley stored on the surface of the soil than on residues from the previous fall. Conidial numbers of Bipolaris sorokiniana and Drechslera teres on residues of wheat and barley, and pseudothecia of Pyrenophora teres on residues of barley decreased over one winter but these pathogens continued to sporulate at low levels after two winters. With residue from the soil surface, Drechslera teres and B. sorokiniana conidia occurred in greater numbers on lower parts of the plants. Drechslera teres occurred primarily on leaf and sheath areas and B. sorokiniana, on sheath and stem areas, while P. teres sporulated mainly on stems. Numbers of conidia of D. teres may have declined because the pathogen occurred mainly on leaves, which disintegrated after one winter. The wheat pathogen Stagonospora nodorum was able to sporulate on ...
{"title":"Survival of leaf spot pathogens on crop residues of wheat and barley in Saskatchewan.","authors":"L. Duczek, K. Sutherland, S. Reed, K. Bailey, G. Lafond","doi":"10.1080/07060669909501208","DOIUrl":"https://doi.org/10.1080/07060669909501208","url":null,"abstract":"Pycnidia of Stagonospora nodorum, and pseudothecia of Phaeosphaeria nodorum and Pyrenophora triticirepentis occurred in greater numbers after one overwintering period on residues of wheat and barley stored on the surface of the soil than on residues from the previous fall. Conidial numbers of Bipolaris sorokiniana and Drechslera teres on residues of wheat and barley, and pseudothecia of Pyrenophora teres on residues of barley decreased over one winter but these pathogens continued to sporulate at low levels after two winters. With residue from the soil surface, Drechslera teres and B. sorokiniana conidia occurred in greater numbers on lower parts of the plants. Drechslera teres occurred primarily on leaf and sheath areas and B. sorokiniana, on sheath and stem areas, while P. teres sporulated mainly on stems. Numbers of conidia of D. teres may have declined because the pathogen occurred mainly on leaves, which disintegrated after one winter. The wheat pathogen Stagonospora nodorum was able to sporulate on ...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80818295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-06-01DOI: 10.1080/07060669909501211
G. Hausner, K. Rashid, E. Kenaschuk, J. Procunier
A cleaved amplified polymorphic sequence (CAPS) marker has been developed for the flax rust resistance gene M3. This molecular marker was identified in a rust differential for M3 by screening primer sets, whose sequences were based on the nucleotide sequence of the M gene. One primer set was identified that co-amplified, along with other related sequences, a 2.9-kb DNA segment of M3 or an M-like gene tightly linked to the M3 locus. Restriction fragment analysis revealed several unique DNA fragments that were linked to the presence of the M3 gene in a F2 segregating population. This molecular marker along with recently developed markers for the L2, L6, L9, and L11 alleles will be useful for marker-assisted selection in breeding programs for obtaining multigenic resistance against flax rust in Canadian flax cultivars.
{"title":"The identification of a cleaved amplified polymorphic sequence (CAPS) marker for the flax rust resistance gene M3","authors":"G. Hausner, K. Rashid, E. Kenaschuk, J. Procunier","doi":"10.1080/07060669909501211","DOIUrl":"https://doi.org/10.1080/07060669909501211","url":null,"abstract":"A cleaved amplified polymorphic sequence (CAPS) marker has been developed for the flax rust resistance gene M3. This molecular marker was identified in a rust differential for M3 by screening primer sets, whose sequences were based on the nucleotide sequence of the M gene. One primer set was identified that co-amplified, along with other related sequences, a 2.9-kb DNA segment of M3 or an M-like gene tightly linked to the M3 locus. Restriction fragment analysis revealed several unique DNA fragments that were linked to the presence of the M3 gene in a F2 segregating population. This molecular marker along with recently developed markers for the L2, L6, L9, and L11 alleles will be useful for marker-assisted selection in breeding programs for obtaining multigenic resistance against flax rust in Canadian flax cultivars.","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89919434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-06-01DOI: 10.1080/07060669909501201
P. A. Rollins, A. Keinath, M. Farnham
Three-week-old seedlings of cabbage cv. Bravo were inoculated with either infested cornmeal-sand cultures (9.1 x 104 colony-forming units per kg soil) or selerotia (50 per kg soil) of isolates of Rhizoctonia solani anastomosis group (AG) 2-1 (five isolates) or AG4 (five isolates). Wirestem incidence (percentage of diseased and dead plants), severity on hypocotyls and roots (rated on a l-lO scale), and plant fresh weight were assessed two weeks after inoculation. Wirestem incidence and severity were greater and plant weight was lower with cornmeal-sand inoculum than with sclerotial inoculum. As a group, isolates belonging to AG4 were significantly more virulent than those of AG2-1 under conditions of this study. Within each AG, isolates could be separated based on virulence with either inoculum type. Use of sclerotial inoculum of a virulent isolate of R. solani AG4 or AG2-1 would provide the most practical means to screen Brassica oleracea germplasm.
{"title":"Effect of inoculum type and anastomosis group of Rhizoctonia solani causing wirestem of cabbage seedlings in a controlled environment","authors":"P. A. Rollins, A. Keinath, M. Farnham","doi":"10.1080/07060669909501201","DOIUrl":"https://doi.org/10.1080/07060669909501201","url":null,"abstract":"Three-week-old seedlings of cabbage cv. Bravo were inoculated with either infested cornmeal-sand cultures (9.1 x 104 colony-forming units per kg soil) or selerotia (50 per kg soil) of isolates of Rhizoctonia solani anastomosis group (AG) 2-1 (five isolates) or AG4 (five isolates). Wirestem incidence (percentage of diseased and dead plants), severity on hypocotyls and roots (rated on a l-lO scale), and plant fresh weight were assessed two weeks after inoculation. Wirestem incidence and severity were greater and plant weight was lower with cornmeal-sand inoculum than with sclerotial inoculum. As a group, isolates belonging to AG4 were significantly more virulent than those of AG2-1 under conditions of this study. Within each AG, isolates could be separated based on virulence with either inoculum type. Use of sclerotial inoculum of a virulent isolate of R. solani AG4 or AG2-1 would provide the most practical means to screen Brassica oleracea germplasm.","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75963722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-06-01DOI: 10.1080/07060669909501205
R. Peters, H. W. Platt, R. Hall
A comparison of allozyme banding patterns at two loci, for glucose-6-phosphate isomerase (Gpi) and peptidase (Pep), with markers for mating type, metalaxyl sensitivity, and cultural morphology revealed eight distinct genotypes among 726 isolates of Phytophthora infestans collected in Canada between 1994 and 1996. Banding patterns for allozymes of the Gpi locus alone proved to be adequate for distinguishing seven of the genotypes. Five of these genotypes (US-l, US-6, US-7, US-8, and gll (or US-ll)) were comparable to genotypes described in the United States. The US-l genotype (Al mating type, metalaxyl-sensitive) was recovered commonly (41% frequency) throughout Canada (outside the province of British Columbia) during 1994. By 1996, the US-l genotype was no longer recovered from any samples of potato or tomato tissue taken from across Canada. The US-8 genotype (A2 mating type, metalaxyl-insensitive) dominated populations of the pathogen in Ontario, Quebec, and New Brunswick during 1994 and by 1996, the US-...
{"title":"USE OF ALLOZYME MARKERS TO DETERMINE GENOTYPES OF PHYTOPHTHORA INFESTANS IN CANADA","authors":"R. Peters, H. W. Platt, R. Hall","doi":"10.1080/07060669909501205","DOIUrl":"https://doi.org/10.1080/07060669909501205","url":null,"abstract":"A comparison of allozyme banding patterns at two loci, for glucose-6-phosphate isomerase (Gpi) and peptidase (Pep), with markers for mating type, metalaxyl sensitivity, and cultural morphology revealed eight distinct genotypes among 726 isolates of Phytophthora infestans collected in Canada between 1994 and 1996. Banding patterns for allozymes of the Gpi locus alone proved to be adequate for distinguishing seven of the genotypes. Five of these genotypes (US-l, US-6, US-7, US-8, and gll (or US-ll)) were comparable to genotypes described in the United States. The US-l genotype (Al mating type, metalaxyl-sensitive) was recovered commonly (41% frequency) throughout Canada (outside the province of British Columbia) during 1994. By 1996, the US-l genotype was no longer recovered from any samples of potato or tomato tissue taken from across Canada. The US-8 genotype (A2 mating type, metalaxyl-insensitive) dominated populations of the pathogen in Ontario, Quebec, and New Brunswick during 1994 and by 1996, the US-...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85193103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-06-01DOI: 10.1080/07060669909501209
R. Knox, M. R. Fernandez, A. Brûlé-Babel, R. M. Pauw
The genetics of resistance in wheat (Triticum aestivum L.) to loose smut caused by Ustilago tritici (Pers.) Rostr. is not well understood. In this study the inheritance of loose smut resistance was studied in two androgenetically derived doubled haploid populations and two inbred random head-to-row populations. The loose smut resistant experimental wheat line HY377 was crossed with the loose smut susceptible line L8474-D1 and the resistant line SC8021V2. Androgenetically derived doubled haploid populations and F4-derived random inbred line populations were produced from each of the crosses HY377/L8474-D1 and HY377/SC8021V2. Lines derived from each cross were grown in the growth room and inoculated with individual and a mixture of races of loose smut. The segregation of resistance between HY377 and L8474-D1 to races T2, T10, T19, and T39 in both doubled haploid and random inbred line populations fit the expected ratio for a single major gene. The same populations inoculated to race T15 showed a different d...
{"title":"Inheritance of loose smut (Ustilago tritici) resistance in two hexaploid wheat (Triticum aestivum) lines","authors":"R. Knox, M. R. Fernandez, A. Brûlé-Babel, R. M. Pauw","doi":"10.1080/07060669909501209","DOIUrl":"https://doi.org/10.1080/07060669909501209","url":null,"abstract":"The genetics of resistance in wheat (Triticum aestivum L.) to loose smut caused by Ustilago tritici (Pers.) Rostr. is not well understood. In this study the inheritance of loose smut resistance was studied in two androgenetically derived doubled haploid populations and two inbred random head-to-row populations. The loose smut resistant experimental wheat line HY377 was crossed with the loose smut susceptible line L8474-D1 and the resistant line SC8021V2. Androgenetically derived doubled haploid populations and F4-derived random inbred line populations were produced from each of the crosses HY377/L8474-D1 and HY377/SC8021V2. Lines derived from each cross were grown in the growth room and inoculated with individual and a mixture of races of loose smut. The segregation of resistance between HY377 and L8474-D1 to races T2, T10, T19, and T39 in both doubled haploid and random inbred line populations fit the expected ratio for a single major gene. The same populations inoculated to race T15 showed a different d...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78764645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-06-01DOI: 10.1080/07060669909501199
R. Utkhede, E. Hogue
The influence of ground cover with fall rye, perennial rye grass, oats, canola, quack grass, and timothy grass on percent mortality and disease severity ratings of phytophthora crown and root rot of apple trees was determined over five years under orchard conditions in the Okanagan Valley of British Columbia. Fall rye and perennial rye grass significantly (P = 0.05) reduced the disease compared with the hand-weeded control. There were no significant differences in the percent tree mortality among the timothy grass, quack grass, oats, canola, and the hand-weeded control treatments. These results indicate that use of fall rye or perennial rye grass as a ground cover will reduce the incidence of phytophthora crown and root rot of apple trees planted in sandy soils of nurseries or orchards where the disease is present and conditions are sufficiently wet.
{"title":"INFLUENCE OF GROUND COVER ON DEVELOPMENT OF PHYTOPHTHORA CROWN AND ROOT ROT OF APPLE TREES","authors":"R. Utkhede, E. Hogue","doi":"10.1080/07060669909501199","DOIUrl":"https://doi.org/10.1080/07060669909501199","url":null,"abstract":"The influence of ground cover with fall rye, perennial rye grass, oats, canola, quack grass, and timothy grass on percent mortality and disease severity ratings of phytophthora crown and root rot of apple trees was determined over five years under orchard conditions in the Okanagan Valley of British Columbia. Fall rye and perennial rye grass significantly (P = 0.05) reduced the disease compared with the hand-weeded control. There were no significant differences in the percent tree mortality among the timothy grass, quack grass, oats, canola, and the hand-weeded control treatments. These results indicate that use of fall rye or perennial rye grass as a ground cover will reduce the incidence of phytophthora crown and root rot of apple trees planted in sandy soils of nurseries or orchards where the disease is present and conditions are sufficiently wet.","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73307506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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