scholarly journals Development of a PCRRFLP method to distinguish species within the Ilyonectria macrodidyma complex

2014 ◽  
Vol 67 ◽  
pp. 151-156 ◽  
Author(s):  
M.A. Outram ◽  
E.E. Jones ◽  
M.V. Jaspers ◽  
H.J. Ridgway

Species within the Ilyonectria macrodidyma complex are known plant pathogens and several are implicated as the causal agents of black foot disease of grapevines The seven species within the complex can be identified by DNA sequencing of the histone H3 gene In this study a PCRRFLP method to identify the species was developed In silico digestion of the 500 bp histone H3 amplimer using MnlI showed that it could identify Ilyonectria sp 1 Ilyonectria sp 2 I alcacerensis and I macrodidyma Subsequent in silico digestion with Hinf1 identified I estremocensis I novozelandica and I torresensis The PCRRFLP was validated using a collection of 40 I macrodidyma complex isolates that had been recovered from symptomatic grapevines Ilyonectria macrodidyma I novozelandica and I torresensis were detected in that collection Intraspecific polymorphism was only detected in I torresensis This method provides a rapid procedure for identifying individual species of the I macrodidyma species complex

Plant Disease ◽  
2014 ◽  
Vol 98 (4) ◽  
pp. 567-567 ◽  
Author(s):  
R. F. dos Santos ◽  
E. Blume ◽  
M. F. B. Muniz ◽  
S. M. Steckling ◽  
G. W. Burtet ◽  
...  

Since 1999, the decline of American grapevines (Vitis labrusca L.) has been common in Rio Grande do Sul, Brazil (1). In August 2012, V. labrusca with black foot symptoms were collected in vineyards in the Serra Gaúcha Region. Symptomatic plants had low vigor, vascular lesions, delayed budding, and decline and death of vines. Symptomatic roots had necrotic lesions and reduced biomass. Fungal isolations were made from necrotic root and crown fragments (own-rooted cultivar) on potato dextrose agar (PDA) medium amended with 0.5 g L–1 streptomycin sulfate. Putative colonies of “Cylindrocarpon” pauciseptatum Schroers & Crous were obtained from single macroconidia isolations. Two isolates were used to confirm the identity of isolated colonies: Cy12UFSM and Cy13UFSM. After incubation in the dark for 10 days at 20°C, the isolated mycelial colonies, which were cottony white to felty in texture, became dark orange to brown. Both isolates produced chlamydospores in chains at 40 days. Chlamydospores of Cy12UFSM and Cy13UFSM were 9 to 12 μm and 5 to 11.5 μm in diameter. Sporodochia formation on carnation leaf agar (CLA) medium was observed after 30 days. To encourage development of conidia, the isolates were grown on spezieller nährstoffarmer agar (SNA) medium for five weeks at 20°C with addition of two pieces of 1 cm2 filter paper. Microconidia of Cy12UFSM were 4 to 8.5 × 3.5 to 5 μm and those of Cy13UFSM were 3.5 to 7.5 × 3 to 5 μm. Macroconida were predominantly 3-septate (Cy12UFSM was 36 to 45 × 7.5 to 9 μm and Cy13UFSM was 30 to 38 × 7.5 to 8 μm), but 1-, 2- septate macroconidia were observed. The sizes of the three spore types and colony morphology for our isolates were similar to those described by Schroers et al. (3) for “C.” pauciseptatum. To further confirm the identity of Cy12UFSM and Cy13UFSM, multi-gene DNA sequence analysis (rDNA-ITS, β-tubulin, and histone H3) was conducted using primer pairs ITS1 and ITS4 (4), Bt2a and Bt2b, and H3-1a and H3-1b (2), which amplify the ITS1-5.8S rRNA-ITS2 genes, part of the β-tubulin gene, and the histone H3 gene, respectively. Sequences of these three regions had 99, 99, and 97% similarity with references sequences of “C.” pauciseptatum (isolate Cy238; accessions ITS [JF735307]; β-tubulin [JF735435], and histone H3 [JF735582], respectively). To evaluate pathogenicity, 4-month-old rooted cuttings of V. labrusca cv. Bordô were inoculated with two isolates by immersing them in a conidial suspension (106 conidia ml–1) for 60 min. Ten single-vine replicates were used for each isolate, and 10 water-inoculated vines were included as controls. Thirty days after inoculation, vines were re-inoculated with 40 ml of a 106 conidia ml–1 suspension to ensure root infection. After 4 months, the inoculated plants had reduced root mass relative to controls (39.18% for Cy12UFSM and 18.27% for Cy13UFSM). Inoculated plants also had root and crown necrosis, vascular lesions, shoot decline, and vine mortality (60 and 80% mortality for Cy12UFSM and Cy13UFSM, respectively). All water-inoculated control plants remained symptomless. The fungi Cy12UFSM and Cy13UFSM were re-isolated from infected woody tissues, confirming Koch's postulates. To our knowledge, this is the first report of “C.” pauciseptatum associated with black foot disease of grapevine in Brazil, which may potentially impact the sustainability of grapevine nurseries and vineyard productivity. References: (1) L. R. Garrido et al. Fitopatol. Brasil. 29:548, 2004. (2) N. L. Glass et al. Appl. Environ. Microbiol. 61:1323, 1995. (3) H. J. Schoers et al. Mycol. Res. 112:82, 2008. (4) T. J. White et al. Amplification Pages 315-322 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.


Plant Disease ◽  
2014 ◽  
Vol 98 (9) ◽  
pp. 1277-1277 ◽  
Author(s):  
D. S. Akgül ◽  
N. G. Savaş ◽  
S. Önder ◽  
S. Özben ◽  
S. Kaymak

Soil-borne fungal diseases have become an important problem in grapevine nurseries of the Aegean region (western Turkey) in recent years. Reduced vigor, black vascular streaking in basal ends, blackish-sunken necrotic root lesions, and young vine death were observed in 15 grapevine nurseries of Manisa city in May 2011 and 2012. To determine the causal agents, symptomatic young grapevine (Vitis vinifera cv. Sultana 7) plants (grafted on 1103 Paulsen) were collected from nurseries (8 to 10 plants from each). Symptomatic basal end tissues were surface disinfested with 95% ethanol and flame sterilized. The internal tissues were plated onto potato dextrose agar amended with tetracycline (0.01%). Campylocarpon-like fungi were isolated (with 37.9% isolation frequency) from only one nursery (corresponding to 6.7% of all surveyed nurseries). Fungal colonies were incubated for 21 days in the dark to induce sporulation. Fungal colonies produced cottony aerial mycelium and turned chocolate-brown to dark brown on PDA. Abundant macroconidia were observed at branched conidiophores on long and cylindrical phialides. Microconidia were not observed. Macroconidia were generally 2 to 4 septate, cylindrical and slightly curved, with the following dimensions: 2 septate: 33.5 to 40.7 × 6.1 to 7.6 μm (mean: 35.9 × 6.8 μm), 3 septate: 36.2 to 43.4 × 6.6 to 8.3 μm (mean: 37.3 × 7.6 μm), and 4 septate: 48.9 to 53.5 × 7.6 to 8.3 μm (mean: 50.7 × 8.0 μm). Fifty macroconidia were measured. Morphologically, the isolates resembled the published description of Campylocarpon fasciculare Schroers, Halleen & Crous (2,4). For molecular identification, fungal DNA was extracted from mycelium and ribosomal DNA fragments (ITS1, 5.8S ITS2 rDNA), β-tubulin, and histone H3 genes, amplified with ITS 4-5, Bt 2a-2b, and H3 1a-1b primers (3,5), and sequenced. Sequences were compared with those deposited in GenBank. The isolate (MBAi45CL) showed 99% similarity with Campylocarpon fasciculare isolates AY677303 (ITS), AY377225 (β-tubulin), and JF735502 (histone H3). The DNA sequences were deposited into GenBank under accessions KJ573392, KJ573393, and KJ573394 for ITS, β-tubulin, and Histone H3 genes, respectively. To fulfill Koch's postulates, pathogenicity tests were conducted under greenhouse conditions on own-rooted grapevines (Vitis vinifera) cv. Sultana 7. Plants were removed from the rooting bench and the roots were slightly trimmed and submerged in a 107 ml–1 conidial suspension of the isolate for 60 min (5). After inoculation, the rooted cuttings were planted in 1-liter bags containing a mixture of soil, peat, and sand (2:1:1, v/v/v), and maintained in the greenhouse (24°C. 16/8-h day/night, 75% RH). Ten plants were inoculated with the isolate and five plants were submerged in sterile distilled water (control). After 4 months, young vines were examined for vascular discoloration, reduced root biomass, blackish lesions, and recovery of fungal isolates. The experiment was repeated twice. Blackish-brown discoloration of xylem vessels and necrosis in the basal ends was visible in the inoculated plants but not in the control plants. The pathogen was successfully re-isolated from 69.1% of the inoculated plants. This report is important for the new studies aiming at black foot disease control in Turkey viticulture. References: (1) A. Cabral et al. Phytopathol. Mediterr. 51:340, 2012. (2) P. Chaverri et al. Stud. Mycol. 68:67, 2011. (3) N. L. Glass and G. C. Donaldson. Appl. Environ. Microbiol. 61:1323, 1995. (4) F. Halleen et al. Stud. Mycol. 50:431, 2004. (5) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.


Plant Disease ◽  
2014 ◽  
Vol 98 (1) ◽  
pp. 156-156 ◽  
Author(s):  
R. F. dos Santos ◽  
E. Blume ◽  
M. F. B. Muniz ◽  
L. I. Heckler ◽  
G. Finger ◽  
...  

Cultivated grapevine (Vitis labrusca and V. vinifera) is of considerable economic importance to the Brazilian fruit industry for both fresh market consumption and for the production of wines, sparkling beverages, and juices. Black foot disease is caused by fungi of the genera Ilyonectria P. Chaverri & C. Salgado (anamorph: Cylindrocarpon Wollew.), Campylocarpon Halleen, Schroers & Crous, and Cylindrocladiella Boesew. In 2012, 4- to 40-year-old grapevines (Vitis spp.) showing reduced vigor, vascular lesions, necrotic root lesions, delayed budding, vine decline, and death were collected from seven locations at Rio Grande do Sul state, Brazil. Fungal isolations were made from root fragments and crown lesions (at least 2 cm above the bottom) on potato dextrose agar (PDA) medium added with 0.5 g L–1 streptomycin sulfate. Eight isolates were obtained and identified on the basis of morphological features and multi-gene analysis (rDNA-ITS, β-tubulin, and histone H3) as Ilyonectria macrodidyma (Halleen, Schroers & Crous) P. Chaverri & C. Salgado. One representative isolate (Cy5UFSM) was used for more detailed morphological and molecular characterization, and pathogenicity confirmation. When incubated in the dark at 20°C for 7 to 10 days, colonies of felty straw-colored mycelium (3) 4.79 cm diameter on average were observed. No sporodochia or other fruiting bodies were produced on carnation leaf agar (CLA) medium after 30 days. Microconidia that were produced after 5 weeks on spezieller nährstoffarmer agar (SNA) medium with addition of two pieces of 1 cm2 filter paper showed ovoid and ellipsoid shape (6.4 × 3.6 μm) and one-septate macroconidia (17.3 × 4.1 μm). To confirm the species, primer pairs ITS1 and ITS4 (4); Bt2a and Bt2b; and H3-1a and H3-1b (2) were used to amplify the ITS1-5.8S rRNA-ITS2, part of the β-tubulin and histone H3 genes, respectively. Sequences of these three regions showed 99, 100, and 100% of homology with I. macrodidyma, respectively. To confirm pathogenicity, 4-month-old rooted cuttings of V. labrusca cv. Bordô were inoculated by immersing them in a conidial suspension of the isolate (106 conidia ml–1) for 60 min (1). Thirty days later, inoculation was performed again by drenching the crown with 40 ml of 106 conidia ml–1 suspension to ensure infection of the roots. In the control treatment, plants were inoculated with sterile distilled water. Plants inoculated with I. macrodidyma showed necrosis of the leaf ribs, reduction in root mass, root and crown necrosis, browning of vessels, drying of shoots, and death. I. macrodidyma was re-isolated from the crown necrosis and vascular lesions, confirming Koch's postulates. To our knowledge, this is the first report of I. macrodidyma associated with black foot disease of grapevine in Brazil, which poses considerable threat to the industry unless management options are realized. References: (1) A. Cabral et al. Phytopathol. Mediterr. 51:340, 2012. (2) N. L. Glass et al. Appl. Environ. Microbiol. 61:1323, 1995. (3) R. W. Rayner. A Mycological Colour Chart. Commonwealth Mycological Institute and British Mycological Society, 1970. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.


Diversity ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 218 ◽  
Author(s):  
Jessica Sánchez ◽  
Paola Iturralde ◽  
Alma Koch ◽  
Cristina Tello ◽  
Dennis Martinez ◽  
...  

Andean blackberry (Rubus glaucus Benth) plants from the provinces of Tungurahua and Bolivar (Ecuador) started showing symptoms of black foot disease since 2010. Wilted plants were sampled in both provinces from 2014 to 2017, and fungal isolates were obtained from tissues surrounding necrotic lesions in the cortex of the roots and crown. Based on morphological characteristics and DNA sequencing of histone 3 and the translation elongation factor 1α gene, isolates were identified as one of seven species, Ilyonectria vredehoekensis, Ilyonectria robusta, Ilyonectria venezuelensis, Ilyonectria europaea, Dactylonectria torresensis, or Dactylonectria novozelandica. Pathogenicity tests with isolates from each species, excluding I. europaea and D. novozelandica whose isolates were lost due to contamination, confirmed that the four species tested can produce black foot disease symptoms in Andean blackberry. This is the first report of Dactylonectria and Ilyonectria species causing black foot disease of Andean blackberry.


1998 ◽  
Vol 8 (2) ◽  
pp. 187 ◽  
Author(s):  
H. Jenny Su ◽  
Yueliang Leon Guo ◽  
Ming-Derg Lai ◽  
Jin-ding Huang ◽  
Yawen Cheng ◽  
...  

2009 ◽  
Vol 157 (10) ◽  
pp. 642-645 ◽  
Author(s):  
Hamid Mohammadi ◽  
Sandra Alaniz ◽  
Zia Banihashemi ◽  
Josep Armengol

Plant Disease ◽  
2006 ◽  
Vol 90 (12) ◽  
pp. 1481-1484 ◽  
Author(s):  
Elsa Petit ◽  
Walter Douglas Gubler

We examined the influence of an arbuscular-mycorrhizal fungus, Glomus intraradices (INVAM CA 501), on black foot disease caused by the fungus Cylindrocarpon macrodidymum on Vitis rupestris cv. St. George under controlled conditions. Mycorrhizal or nonmycorrhizal grape rootings were inoculated with the pathogen. Eight months following inoculation with the pathogen, we evaluated disease severity, vine growth, and mycorrhizal colonization. Mycorrhizal plants developed significantly less leaf and root symptoms than nonmycorrhizal plants (P = 0.04 and P < 0.0001, respectively). Only nonmycorrhizal grape rootings inoculated with the pathogen had significantly less dry root and leaf weights compared with the noninoculated control (P = 0.0021 and P = 0.0017, respectively). Mycorrhizal colonization was high (48.3% for the noninfected control and 54.5% for plants infected with C. macrodidymum) and not significantly affected by inoculation with C. macrodidymum (P = 0.2256). Thus, V. rupestris preinoculated with G. intraradices were less susceptible to black foot disease than nonmycorrhizal plants. Results from this study suggest that preplant applications of G. intraradices may help prevent black foot disease in the nursery and in the vineyard.


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