{"title":"Occurrence and virulence of Puccinia recondita in Canada in 1979","authors":"D. J. Samborski","doi":"10.1080/07060668109501354","DOIUrl":"https://doi.org/10.1080/07060668109501354","url":null,"abstract":"In 1984, wheat leaf rust, caused by Puccinia recondita, was first observed in Manitoba on June 25. However, dry conditions in much of western Canada limited rust development and the disease did not damage wheat in 1984. Identification of races from leaf rust survey samples was carried out with 19 backcross lines, each with a single gene for resistance. Lines with genes Lr19, Lr21, Lr25, and Lr29and line T6 × PI58548 were resistant to all survey samples tested. Sixteen isolates from Manitoba were virulent on adult plants of Benito which has genes Lr1, Lr2a, Lr12, and Lr13. Virulence on gene Lr16 occurred in 17% of the isolates from Manitoba and greenhouse tests with 15 of these isolates showed that they were virulent on adult plants with gene Lrl3. Virulence on a line with gene Lr26 and on the cultivar Tobari occurred at a low level in the rust population. Virulence patterns of isolates from eastern Canada were similar to those observed in recent years. Fifty-nine virulence combinations were identified, us...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85423667","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}
{"title":"Sensitive detection of banana bunchy top and faba bean necrotic yellows viruses from infected leaves, in vitro tissue cultures, and viruliferous aphids using polymerase chain reaction","authors":"A. Shamloul, A. Hadidi, M. Madkour, K. Makkouk","doi":"10.1080/07060669909501168","DOIUrl":"https://doi.org/10.1080/07060669909501168","url":null,"abstract":"DNA primers for banana bunchy top virus (BBTV) and for faba bean necrotic yellows virus (FBNYV) were constructed based on the nucleotide sequence of DNA component 1 of each virus that contains the viral putative replicase gene. Three pairs of primers for each virus were utilized for standard polymerase chain reaction (PCR) or immunocapture (IC) PCR amplification. DNA fragments of 439, 446, and 476 bp were amplified from extracts of BBTV-infected banana leaves, in vitro tissue culture, and viruliferous aphids. DNA fragments of 487, 931, and 1002 bp from extracts of FBNYV-infected faba bean plants and viruliferous vectors were also amplified. The amplified DNA fragments were identified by size, nucleotide sequence, and (or) hybridization analysis. Virus-specific DNA fragments were absent from amplified extracts of uninfected banana and faba bean tissues as well as from non-viruliferous aphids. The nucleotide sequence of the PCR-amplified major portion (923 nucleotides) of BBTV DNA component 1 of an Egyptian...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81416864","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}
{"title":"Detection of cucumber mosaic cucumovirus in weed species: a cautionary report on nonspecific reactions in ELISA","authors":"E. Sikora, M. Andrianifahanana, John F. Murphy","doi":"10.1080/07060669909501169","DOIUrl":"https://doi.org/10.1080/07060669909501169","url":null,"abstract":"The reliability of enzyme-linked immunosorbent assay (ELISA) to detect cucumber mosaic cucumovirus (CMV) coat protein (CP) in three weed species (Taraxacum officinale, Gnaphalium obtusifolium, and Conyza canadensis) was compared with other detection methods, including Western blot analysis and a bioassay. Analysis of extracts prepared from these species by double antibody sandwich (DAS) ELISA yielded high absorbance values (A4O5nm) that were indicative of CMV concentrations of purified CMV standards of greater than 50 mg/mL. However, results from an ELISA procedure designed such that no viral antigen should be detected suggested that the strong ELISA absorbance values were nonspecific reactions with material(s) in the weed extracts. These findings were substantiated when no CMV CP was detected by Western blot analysis or infectious CMV was detected in bioassays involving inoculation of extracts onto an indicator host (Cucurbita pepo ‘Crookneck’ (squash)). In both DAS ELISA and indirect ELISA procedures, t...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90644661","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}
{"title":"Movement and distribution of tomato spotted wilt virus in resistant and susceptible accessions of Capsicum spp.","authors":"S. Soler, M. Díez, S. Roselló, F. Nuez","doi":"10.1080/07060669909501167","DOIUrl":"https://doi.org/10.1080/07060669909501167","url":null,"abstract":"Resistant Capsicum chinense accessions PI-152225 and PI-159236 and the susceptible cultivar ‘Negral’ of Capsicum annuum were used in three experiments to characterize the resistance to tomato spotted wilt virus (TSWV) in these materials. In the first experiment viral movement in the whole plant was studied at two growth stages (2- and 4-leaf stage). In the second experiment the movement within the inoculated leaf was analysed at three growth stages (2-, 3-, and 4-leaf stage). Two techniques were used in this assay: double antibody sandwich – enzyme-linked immunosorbent assay (DAS–ELISA) and direct tissue blotting (DTB). In the latter experiment viral accumulation in different types of samples was evaluated by DAS–ELISA. The DTB technique showed that viral movement within the inoculated leaf is restricted in the resistant plants. The inoculated area was not totally infected in resistant accessions and slower viral movement within the inoculated area was observed. Detection of weak ELISA positives in inocul...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91071964","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}
{"title":"Residual efficacy of Typhula phacorrhiza as a biocontrol agent of grey snow mold on creeping bentgrass","authors":"T. Hsiang, C. Wu, S. Cook","doi":"10.1080/07060669909501175","DOIUrl":"https://doi.org/10.1080/07060669909501175","url":null,"abstract":"Isolates of the biocontrol fungus Typhula phacorrhiza were evaluated in field tests over a 5-year period for suppression of grey snow mold caused by Typhula incarnata and Typhula ishikariensis. Of the hundreds of T. phacorrhiza isolates collected from across southern Ontario in the spring of 1994, 42 were cultured on mixed grains and applied in the late fall to creeping bentgrass (Agrostis palustris) at a rate of 200 g/m2 (4 x 105 cfu/m2) along with inocula of T. incarnata or T. ishikariensis at 10 g/m2 (2 x 104 cfu/m2). In late fall of each year from 1995 to 1998, T. incarnata and T. ishikariensis were reapplied to the same plots, but not T. phacorrhiza. Plots were rated for disease after snowmelt in each year from 1995 to 1999. During the first three years, high positive correlations of winter injury were found between the suppression trials, with several isolates showing significant control of grey snow mold. By the fourth year after inoculation, suppression of snow mold in plots treated with the most ...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85453670","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}
{"title":"Histology of quantitative resistance in flax to the flax rust fungus (Melampsora lini)","authors":"A. Kowalska, R. Niks","doi":"10.1080/07060669909501171","DOIUrl":"https://doi.org/10.1080/07060669909501171","url":null,"abstract":"Macroscopical and histological research is useful to characterize quantitative resistance. Analysis of histological components of the resistance to the flax rust fungus (Melampsora lini) was carried out on seedlings of seven flax (Linum usitatissimum) accessions: five fibre flax accessions with various levels of quantitative resistance and two near-isogenic lines of linseed with gene K or NI. Flax seedlings were inoculated with uredospores. Collected leaves of the flax accessions were stained with Chlorazol Black E. It was found that in the pathosystem flax - M. lini, a lower number of pustules (lower infection frequency) on quantitatively resistant accessions did not result from mechanisms acting before stomatal penetration by the fungus. Reduced infection frequency was associated with increased rates of early abortion of the rust fungus but rates of this abortion were not large enough to explain the low infection frequency on the quantitatively resistant accessions Afganistan and Solido. In both of the ...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81565816","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}
{"title":"Reaction of wild crucifers to Leptosphaeria maculans, the causal agent of blackleg of crucifers","authors":"C. -. Chen, G. Séguin-Swartz","doi":"10.1080/07060669909501172","DOIUrl":"https://doi.org/10.1080/07060669909501172","url":null,"abstract":"Cotyledons, leaves, and stems of the wild crucifers Arabidopsis thaliana, Diplotaxis muralis, Diplotaxis tenuifolia, and Raphanus raphanistrum and cotyledons and leaves of Sisymbrium loeselii were inoculated with pycnidiospores of an aggressive isolate of Leptosphaeria maculans, the cause of blackleg of crucifers. All species except R. raphanistrum expressed a high level of resistance to L. maculans; the resistance was characterized by rapid cell death, tissue browning, and lignin deposition. In R. raphanistrum, the reaction of cotyledons and leaves ranged from a hypersensitive-like response to extensive tissue collapse and necrosis comparable to that observed in susceptible Brassica napus cv. Westar; stem tissue of R. raphanistrum, however, was highly resistant to L. maculans. The fungus was recovered from necrotic cotyledon and leaf tissue of all the wild crucifers 10 and 20 days postinoculation, respectively, and from stem tissue of D. muralis around the point of inoculation 40 days postinoculation.","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82517293","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}
{"title":"Reduction of potato scab, Verticillium wilt, and nematodes by soymeal and meat and bone meal in two Ontario potato fields.","authors":"G. Lazarovits, K. Conn, J. Potter","doi":"10.1080/07060669909501170","DOIUrl":"https://doi.org/10.1080/07060669909501170","url":null,"abstract":"Soymeal (SM) and meat and bone meal (MBM) were incorporated into soil to a depth of 15 cm at a rate of 37 t/ha at two commercial potato (Solatium tuberosum) fields in Ontario in the spring of 1996. The incidence of verticillium wilt and potato scab, the population of plant parasitic nematodes, and the soil chemistry and microbiology were monitored in three subsequent crops of potatoes in 1996-1998. Verticillium dahliae microsclerotia (MS) were buried in the soil immediately after incorporation of the amendments, both in the field and in a concurrent laboratory assay using soil from the field placed in test tubes, and the viability of the MS was determined 4 weeks later. Both treatments reduced the incidence of verticillium wilt, potato scab, and the nematode population to near zero levels in 1996. Reduced disease levels were still evident in the 1997 crop, but by 1998, disease levels were equal to or higher than those in the control treatments. Nematode numbers remained below control levels for the 3 year...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79717962","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}
{"title":"Severity of late blight tuber infection caused by US-1 and US-8 genotypes of Phytophthora infestans in 12 potato cultivars","authors":"M. Medina, H. W. Platt, R. Peters","doi":"10.1080/07060669909501176","DOIUrl":"https://doi.org/10.1080/07060669909501176","url":null,"abstract":"Twelve potato cultivars (cvs. AC-Novachip, Atlantic, Chieftain, Kennebec, Ranger Russet, Red Pontiac, Russet Burbank, Russet Norkotah, Shepody, Snowden, Superior, and Yukon Gold) were assessed for their response to inoculation with isolates of US-l and to US-8 genotypes of Phytophthora infestans. All cultivars (with the exception of cv. Yukon Gold) developed significantly more surface necrosis due to US-8 (20% to 87% surface area necrosis) than US-l (13% to 46% necrosis). Penetration into the tuber tissue, measured as average depth of interior necrosis of stem, side, and eye regions, also revealed significant differences in the ability of the two genotypes to become established in internal tuber tissues. The cvs. AC-Novachip, Kennebec, Red Pontiac, Russet Burbank, and Russet Norkotah were penetrated more deeply by US-8 than US-l. The other cultivars were penetrated equally by isolates of both genotypes of the pathogen. These results indicate that introduced US-8 populations of P. infestans are more aggres...","PeriodicalId":9607,"journal":{"name":"Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77355382","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}