scholarly journals A Specific and Sensitive Method for the Detection of Colletotrichum lindemuthianum in Dry Bean Tissue

Plant Disease ◽  
2007 ◽  
Vol 91 (10) ◽  
pp. 1271-1276 ◽  
Author(s):  
Yong-Yan Chen ◽  
R. L. Conner ◽  
C. L. Gillard ◽  
G. J. Boland ◽  
C. Babcock ◽  
...  

To facilitate early diagnosis and improve control of bean anthracnose, a rapid, specific, and sensitive polymerase chain reaction (PCR)-based method was developed to detect the causal agent, Colletotrichum lindemuthianum, in bean (Phaseolus vulgaris) seed. Based on sequence data of the rDNA region consisting of the 5.8S gene and internal transcribed spacers (ITS) 1 and 2 of four C. lindemuthianum races and 17 Colletotrichum species downloaded from GenBank, five forward primers were designed and evaluated for their specificity. Among them, one forward primer was selected for use in combination with ITS4 to specifically detect C. lindemuthianum. A 461-bp specific band was amplified from the genomic DNA template of 16 representative isolates of C. lindemuthianum, but not from 58 representative isolates of 17 other Colletotrichum species or 10 bean pathogens. Moreover, to enhance the sensitivity of detection, nested PCR was applied, which allowed the detection of as little as 10 fg of C. lindemuthianum genomic DNA and 1% infected seed powder, which was mixed with 99% healthy seed powder. The diagnostic analysis can be completed within 24 h, compared with about 2 weeks required for culturing. Furthermore, this method can be performed and interpreted by personnel with no specialized taxonomic expertise.

Plant Disease ◽  
1997 ◽  
Vol 81 (1) ◽  
pp. 71-76 ◽  
Author(s):  
N. Ntahimpera ◽  
H. R. Dillard ◽  
A. C. Cobb ◽  
R. C. Seem

Three tillage practices—chiseling, rototilling, and moldboard plowing—were evaluated in 1993 and 1994 to determine their impact on initial disease development, distribution, and progression over time in a field of the susceptible kidney bean cultivar Horizon. The tillage treatments were administered in the spring in a field infested in 1992 with the bean anthracnose pathogen, Colletotrichum lindemuthianum race β. Initial disease incidence was highest in the chiseled plots, where more bean debris was left on the surface than in the other treatments. Significantly higher final disease incidence and area under the disease progress curve (AUDPC) occurred in the chiseled plots than in the rototilled and moldboard plowed plots. There was a significant correlation (r = 0.75) between the percentage of debris left on the surface and subsequent disease incidence on pods in the field. Anthracnose incidence or severity in the field was highly correlated with disease incidence on harvested pods (r values ranged between 0.87 and 0.98). Results from the ordinary runs analysis showed that anthracnose occurred randomly within the field early in the season, indicating that initial inoculum was from bean debris within the field. Later in the season, plant-to-plant spread resulted in a more clustered distribution of diseased plants.


2012 ◽  
Vol 721 ◽  
pp. 85-91 ◽  
Author(s):  
Yu Kyung Tak ◽  
Won Young Kim ◽  
Min Jung Kim ◽  
Eunyoung Han ◽  
Myun Soo Han ◽  
...  

Plant Disease ◽  
2001 ◽  
Vol 85 (2) ◽  
pp. 220-225 ◽  
Author(s):  
H. K. Lee ◽  
J. P. Tewari ◽  
T. K. Turkington

A polymerase chain reaction (PCR)-based diagnostic assay was developed to detect Rhynchosporium secalis, the barley scald fungus, in barley seed. Species-specific primers were designed based on sequence data of a region consisting of the 5.8S RNA gene and internal transcribed spacers 1 and 2 of R. secalis. The sequenced regions showed 100% homology between the two R. secalis isolates and 93% homology between R. secalis and R. orthosporum. Five sets of synthesized oligonucleotide primers were tested for their specificity using 29 isolates of R. secalis of diverse geographic origins and from different barley cultivars. In addition, DNA extracts from 22 species of microbes either taxonomically related to or from the same niche as R. secalis were tested as negative controls. Among five sets of primers, a primer set, RS8 and RS9, was selected for use in detecting R. secalis because it amplified a 264-bp fragment from the DNA of all R. secalis isolates but not the DNA from other species used for validation of the specificity of this primer set. This primer set was also used to detect R. secalis in barley seed and successfully amplified the predicted size of the DNA fragment in the infected material. PCR detection of as little as 1 to 10 pg of R. secalis DNA was possible. The method described here requires 1 day for completion, compared to 10 days required for the cultural method.


Plant Disease ◽  
2002 ◽  
Vol 86 (5) ◽  
pp. 562-562 ◽  
Author(s):  
L. E. del Río ◽  
R. S. Lamppa ◽  
P. L. Gross

Dry bean (Phaseolus vulgaris L. cv. Pintoba) plants showing typical anthracnose symptoms were observed in three commercial fields in North Dakota (Towner, Steele, and Pembina counties) in July 2001. Disease incidence in all fields ranged from 5 to 20%. The fungus was isolated from leaves and pods on potato dextrose agar and identified as Colletotrichum lindemuthianum (Sacc. & Magnus) Lams.-Scrib. (3). Pathogenicity and race identification were determined on a set of 12 standard differentials (2). Three isolates, one from each county, were grown for 7 days in Mathur's medium. Spores were suspended in water and Tween 80 (0.1% vol/vol) and adjusted to 106 spores per ml. Thirty 2-week-old seedlings of each differential were inoculated with each isolate on the adaxial side of the primary leaves using a Paasche airbrush. Inoculated plants were incubated in moist chambers for 5 days at 20°C under 14 h of fluorescent light and then moved back to the greenhouse. Disease reaction was assessed 3 days later. Isolates of C. lindemuthianum races 7 and 73 obtained from J. Kelly (Michigan State University) were used as positive controls. Inoculations were repeated once. All three North Dakota isolates and the positive control for race 73 produced sporulating lesions on the differentials ‘Michelite’, ‘Cornell 49242’, and ‘Mexico 222’. No lesions were observed in the other differentials. An unidentified anthracnose race retrieved from a single plant in 1982 constitutes the first report of the presence of anthracnose in North Dakota (4). In 1992, Michigan breeding materials infected with race 73 were planted in North Dakota (1); upon detection, the infected plants were destroyed and the fields quarantined. The epidemics observed in the 2001 season, developed in sites distant from the places where the Michigan materials were planted and have been associated with a single seed source. To our knowledge, the presence of anthracnose race 73 reported here constitutes the first report of anthracnose in commercial dry bean fields in North Dakota. References: (1) J. D. Kelly et al. Plant Dis. 78:892, 1994. (2) M. A. Pastor-Corrales. Phytopathology 81:694, 1991. (3) B. C. Sutton, The Coelomycetes, CAB International, Wallingford, Oxon, UK, 1980. (4) J. R. Venette and P. A. Donald. Bean Improv. Coop. 26:24, 1983.


2012 ◽  
Vol 92 (1) ◽  
pp. 109-118 ◽  
Author(s):  
C. L. Gillard ◽  
N. K. Ranatunga ◽  
R. L. Conner

Gillard, C. L., Ranatunga, N. K. and Conner, R. L. 2012. The effect of foliar fungicide application timing on the control of dry bean anthracnose. Can. J. Plant Sci. 92: 109–118. Anthracnose caused by Colletotrichum lindemuthianum is a major disease of dry bean (Phaseolus vulgaris L.), reducing seed quality and yield. A study carried out in 2005 and 2006 at Exeter, ON, and at Morden, MB, determined that a sequential application of fungicide at the correct time is crucial for the effective management of the disease. The effect of the fungicides azoxystrobin and pyraclostrobin at four single foliar application timings at 5th trifoliolate (A), 1st flower (B), full flower (C) and 10 d after full flower (D) and at three sequential timings (A+C, B+C, and B+D) were evaluated under low and high disease pressure conditions. Data were collected on leaf vein and pod infection, plant maturity, dockage, pick, seed weight, yield and return on investment. Results were analyzed using analysis of variance (ANOVA) and contrast comparisons were carried out for various treatment combinations. Differences between the two fungicides for leaf symptoms were not apparent under low disease pressure, but occurred early in plant development under high disease pressure. Pyraclostrobin-treated plots produced a higher yield under high disease pressure and better quality seeds at both high and low disease pressure conditions. A single fungicide application at the A timing gave higher yield under low disease pressure, while timings B and C gave a higher yield under high disease pressure. A sequential application often provided greater anthracnose control and improved yield and seed quality, compared with single application timings. For the sequential application timings, the highest yields occurred at the A+C timing under low disease pressure, and at the A+C or B+C timing under high disease pressure.


1993 ◽  
Vol 69 (03) ◽  
pp. 217-220 ◽  
Author(s):  
Jonathan B Rosenberg ◽  
Peter J Newman ◽  
Michael W Mosesson ◽  
Marie-Claude Guillin ◽  
David L Amrani

SummaryParis I dysfibrinogenemia results in the production of a fibrinogen molecule containing a functionally abnormal γ-chain. We determined the basis of the molecular defect using polymerase chain reaction (PCR) to amplify the γ-chain region of the Paris I subject’s genomic DNA. Comparative sequence analysis of cloned PCR segments of normal and Paris I genomic DNA revealed only an A→G point mutation occurring at nucleotide position 6588 within intron 8 of the Paris I γ-chain gene. We examined six normal individuals and found only normal sequence in this region, indicating that this change is not likely to represent a normal polymorphism. This nucleotide change leads to a 45 bp fragment being inserted between exons 8 and 9 in the mature γparis I chain mRNA, and encodes a 15 amino acid insert after γ350 [M-C-G-E-A-L-P-M-L-K-D-P-C-Y]. Alternative splicing of this region from intron 8 into the mature Paris I γ-chain mRNA also results after translation into a substitution of S for G at position γ351. Biochemical studies of 14C-iodoacetamide incorporation into disulfide-reduced Paris I and normal fibrinogen corroborated the molecular biologic predictions that two additional cysteine residues exist within the γpariS I chain. We conclude that the insertion of this amino acid sequence leads to a conformationallyaltered, and dysfunctional γ-chain in Paris I fibrinogen.


2020 ◽  
Vol 100 (1) ◽  
pp. 40-55 ◽  
Author(s):  
Robert L. Conner ◽  
Greg J. Boland ◽  
Chris L. Gillard ◽  
Yongyan Chen ◽  
Xuechan Shan ◽  
...  

Anthracnose, caused by the fungus Colletotrichum lindemuthianum (Sacc. & Magnus) Briosi & Cavara, is one of the most destructive diseases of dry bean (Phaseolus vulgaris L.) in the world. Between 2005 and 2015, commercial fields of dry beans in Manitoba and Ontario were surveyed to determine the frequency of occurrence of races of the anthracnose fungus. Throughout the study, race 73 was most prevalent in Manitoba and Ontario. However, three anthracnose races not previously reported in Canada also were identified. These three new races and four previously identified anthracnose races were used to screen 52 dry bean cultivars, as well as a mung bean and azuki bean cultivar from Ontario, for their seedling reactions to determine their patterns of race resistance. The dry bean cultivars were classified into a total of 19 resistance spectra based on the pattern of seedling reactions to the seven anthracnose races. The most common resistance spectrum was susceptible to the majority of the anthracnose races and no cultivar was resistant to all of the races. Many bean cultivars produced intermediate anthracnose ratings to races 31 and 105 and tests of 16 dry bean cultivars against those races indicated that all cultivars with intermediate ratings to a specific race were segregating in their seedling reactions and none of the cultivars produced plants with only intermediate anthracnose severity ratings. This study provides new information on the anthracnose reactions of common bean cultivars in Canada, which should be useful for the development of new bean cultivars with durable resistance.


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