scholarly journals Susceptibility of four grapevine rootstocks to Cylindrocladiella parva

2013 ◽  
Vol 66 ◽  
pp. 249-253 ◽  
Author(s):  
D.S. Brown ◽  
M.V. Jaspers ◽  
H.J. Ridgway ◽  
C.J. Barclay ◽  
E.E. Jones
Keyword(s):  
Dry Weight ◽  
Conidial Suspension ◽  
Sterile Water ◽  
Rooted Cuttings ◽  
Root Dry Weight ◽  
Shoot Dry Weight ◽  
Foot Disease ◽  
Black Foot ◽  
Black Foot Disease

The susceptibility of four common grapevine rootstocks (10114 Schwarzmann 5C and Riparia Gloire) to Cylindrocladiella parva (black foot disease) infection was assessed in a pot experiment The roots of 4monthold callused rooted cuttings were wounded in situ and inoculated with 50 ml C parva conidial suspension (106/ml) or sterile water (controls) After 6 months of growth shoot dry weight was significantly higher for control plants (242 g) than for those inoculated with C parva (165 g) but did not differ between rootstock varieties Root dry weight was not significantly affected by C parva inoculation but root dry weight of 10114 was significantly higher than other rootstocks Incidence and severity of trunk infection were significantly affected by rootstock variety being lowest in rootstock 10114 plants than other rootstocks None of the rootstocks tested was resistant to this pathogen

scholarly journals The relative susceptibility of grapevine rootstocks to black foot disease is dependent on inoculum pressure

2021 ◽  
Vol 74 (1) ◽  
pp. 62-69
Author(s):  
Carolyn Bleach ◽  
Hayley J. Ridgway ◽  
Marlene V. Jaspers ◽  
E. Eirian Jones
Keyword(s):  
Disease Incidence ◽  
Dry Weight ◽  
Relative Susceptibility ◽  
Shoot Dry Weight ◽  
Foot Disease ◽  
Pathogen Populations ◽  
Inoculation Treatment ◽  
Black Foot ◽  
Black Foot Disease ◽  
Inoculum Pressure

Black foot disease of grapevines is a major economic issue for the viticulture industry worldwide. The disease is mainly associated with a complex of pathogen species within the genera Dactylonectria and Ilyonectria. The susceptibility of six grapevine rootstock cultivars to black foot disease under field conditions was assessed. Callused rootstocks of 101-14, 5C, 420A, Riparia Gloire, Schwarzmann and 3309C were planted into soil containing low natural pathogen populations or inoculated with isolates representing the species diversity in New Zealand. Disease incidence, disease severity and dry weight accumulation were assessed after 8 months of growth. Root and shoot dry weights were not significantly affected by inoculation treatment, but differed among rootstock cultivars, with cultivar 420A having the lowest root and shoot dry weight, cultivar 3309C having the largest shoot dry weight and cultivar 5C the largest root dry weight. The relative susceptibility of rootstocks differed significantly depending on whether they were grown under low natural inoculum pressure or a higher pressure in artificially inoculated soil. Schwarzmann and Riparia Gloire rootstock cultivars were the least susceptible under natural low inoculum pressure, but were the most susceptible in inoculated soil. In contrast, 5C was one of the most susceptible under low inoculum levels but was the least susceptible under high pathogen pressure. The result of the study indicate that black foot pathogen inoculum levels in soil affect the relative susceptibility of grapevine rootstocks to infection, and may have implications for the selection of rootstocks for planting.

scholarly journals First Report of Ilyonectria robusta Associated with Black Foot Disease of Grapevine in Southern Brazil

Plant Disease ◽  
2014 ◽  
Vol 98 (6) ◽  
pp. 845-845 ◽  
Author(s):  
R. F. dos Santos ◽  
E. Blume ◽  
G. B. P. da Silva ◽  
M. Lazarotto ◽  
L. E. Scheeren ◽  
...  
Keyword(s):  
Reference Sequence ◽  
Commonwealth Mycological Institute ◽  
Conidial Suspension ◽  
Southern Brazil ◽  
Vitis Labrusca ◽  
Rooted Cuttings ◽  
First Report ◽  
Foot Disease ◽  
Black Foot ◽  
Black Foot Disease

In August 2012, symptoms of black foot disease were observed on 21-year-old grapevines (Vitis labrusca cv. Bordô; own-rooted cultivar) at Nova Pádua city, Rio Grande do Sul state, Brazil. Symptomatic plants showed reduced vigor, vascular lesions, decline and death of vines, and necrotic lesions on roots. Isolation of fungi associated with necrotic root tissue was made on potato dextrose agar (PDA) medium containing 0.5 g L−1 streptomycin sulfate. Cultures were incubated at 25°C for 7 days in darkness, and single-spore cultures were obtained from the colonies emerging from the diseased tissue. For morphological characterization, cultures were transferred to PDA and spezieller nährstoffarmer agar (SNA) medium with addition of two pieces of 1 cm2 filter paper. One representative isolate (Cy9UFSM) was used for morphological and molecular characterization and pathogenicity confirmation. After 10 days growth on PDA at 20°C in the dark, colonies were umber to chestnut in color (3), appeared cottony to felty in texture, and sporulated profusely. After 5 weeks on SNA and under dark conditions at 20°C, cultures formed macroconidia predominantly on simple conidiophores, 1 to 3 septate, with both ends slightly rounded. Macroconidia varied in size depending on the number of cells as follows: one-septate (23-) 27.7 (-31) × (4.5-) 5.8 (-7) μm; two-septate (26-) 30.1 (-34) × (5-) 5.6 (-6) μm; and three-septate (24-) 31.2 (-35) × (5-) 5.8 (-6.5) μm. Microconidia were observed and did not have a visible hilum (6-) 11.2 (-17) × (3.5-) 4.2 (-5) μm (n = 30 observations per structure). Brown, thick-walled globose to subglobose chlamydospores were produced abundantly on PDA, (8.5-) 13.8 (-17) μm. To confirm the species, primer pairs H3-1a and H3-1b (2) were used to amplify a portion the histone H3 gene. Sequence of this region showed 98% similarity with a reference sequence for Ilyonectria robusta (A.A. Hildebr.) A. Cabral & Crous (GenBank Accession No. JF735530). Thus, both morphological and molecular criteria supported identification of the strain as I. robusta. This isolate was deposited in GenBank as accession KF633172. To confirm pathogenicity, 4-month-old rooted cuttings of Vitis labrusca cv. Bordô were inoculated by immersing roots in a conidial suspension (106 ml−1) for 60 min. After inoculation, the cuttings were planted in 1-L bags containing commercial substrate (MecPlant). Thirty days later, each plant was re-inoculated by applying 40 ml of a conidial suspension (106 ml−1) to the commercial substrate. Ten single-vine replicates were used for each isolate, and 10 water-inoculated vines were included as controls. After 4 months, the inoculated plants showed a 22.5% reduction of root mass, with root and crown necrosis, browning of vessels, and 20% mortality. Control plants treated with water remained symptomless. The fungus was re-isolated from blackened tissue of wood from the basal end of rooted cuttings, thereby satisfying Koch's postulates. I. robusta was first associated with black foot disease of grapevine in Portugal in 2012 (1). To our knowledge, this is the first report in southern Brazil of I. robusta associated with black foot disease of grapevine. References: (1) A. Cabral et al. Mycol. Prog. 11:655, 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.

scholarly journals First Report of Campylocarpon fasciculare Causing Black Foot Disease of Grapevine in Turkey

Plant Disease ◽  
2014 ◽  
Vol 98 (9) ◽  
pp. 1277-1277 ◽  
Author(s):  
D. S. Akgül ◽  
N. G. Savaş ◽  
S. Önder ◽  
S. Özben ◽  
S. Kaymak
Keyword(s):  
Vitis Vinifera ◽  
Dna Sequences ◽  
Histone H3 ◽  
Conidial Suspension ◽  
Water Control ◽  
Western Turkey ◽  
Foot Disease ◽  
Black Foot ◽  
Black Foot Disease ◽  
Β Tubulin

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.

scholarly journals Growth of `October Glory' Red Maple in Multiple Locations in the Southeast

HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 594F-594
Author(s):  
J.L. Sibley ◽  
J.M. Ruter ◽  
D.J. Eakes
Keyword(s):  
Dry Weight ◽  
First Year ◽  
Limited Information ◽  
Red Maple ◽  
Rooted Cuttings ◽  
Root Dry Weight ◽  
Shoot Dry Weight ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Single Location

Limited information exists for container production of red maple cultivars. The objective of this study was to evaluate first-year growth of container-grown `October Glory' at 3 locations with disparate climates in Georgia and Alabama (Tifton, Ga., Blairsville, Ga., and Auburn, Ala.). Rooted cuttings were planted in 9.2-L containers in one location in the same substrate in April 1995. Trees were transported to each location in mid-June and irrigated from overhead risers at 1.3 cm/day for 6 months until dormant, then transported to a single location for harvest. Despite weather differences among locations, final heights were not different (Blairsville 59.8 cm; Auburn 53.0 cm; and Tifton 60.2 cm). Shoot diameter increase and shoot dry weight was greatest at Tifton (8.4 mm, 17.5 g), least at Blairsville (6.3 mm, 9.2 g), with Auburn similar to both locations (6.8 mm, 12.2 g). Root dry weight and root: shoot ratio was greater in Tifton (17.2 g, 0.97) than Blairsville 14.9 g, 0.51) and Auburn (7.0 g, 0.64).

scholarly journals First Report of “Cylindrocarpon” pauciseptatum Associated with Black Foot Disease of Grapevine in Brazil

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 ◽  
...  
Keyword(s):  
Histone H3 ◽  
Vascular Lesions ◽  
Conidial Suspension ◽  
First Report ◽  
Rdna Its ◽  
Foot Disease ◽  
Histone H3 Gene ◽  
Black Foot ◽  
Black Foot Disease ◽  
Β Tubulin

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.

scholarly journals First Report of Ilyonectria macrodidyma Associated with Black Foot Disease of Grapevine in Brazil

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 ◽  
...  
Keyword(s):  
Histone H3 ◽  
Vascular Lesions ◽  
Commonwealth Mycological Institute ◽  
Conidial Suspension ◽  
Fresh Market ◽  
First Report ◽  
Foot Disease ◽  
Black Foot ◽  
Black Foot Disease ◽  
Β Tubulin

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.

Response of Taxus times media var. densiformis to inoculation with arbuscular mycorrhizal fungi

1998 ◽  
Vol 28 (1) ◽  
pp. 150-153
Author(s):  
J N Gemma ◽  
R E Koske ◽  
E M Roberts ◽  
S Hester
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Glomus Intraradices ◽  
Arbuscular Mycorrhizal ◽  
Dry Weight ◽  
Root Systems ◽  
Stem Diameter ◽  
Rooted Cuttings ◽  
Shoot Dry Weight ◽  
Mycorrhizal Plants

Rooted cuttings of Taxus times media var. densiformis Rehd. were inoculated with the arbuscular mycorrhizal fungi Gigaspora gigantea (Nicol. & Gerd.) Gerd. & Trappe or Glomus intraradices Schenck and Smith and grown for 9-15 months in a greenhouse. At the completion of the experiments, leaves of inoculated plants contained significantly more chlorophyll (1.3-4.1 times as much) than did noninoculated plants. In addition, mycorrhizal plants had root systems that were significantly larger (1.3-1.4 times) and longer (1.7-2.1 times) than nonmycorrhizal plants, and they possessed significantly more branch roots (1.3-2.9 times). No differences in stem diameter and height or shoot dry weight were evident at the end of the experiments, although the number of buds was significantly greater in the cuttings inoculated with G. intraradices after 15 months.

The effect of barley yellow dwarf virus on early plant growth in ryegrass (Lolium spp.)

1989 ◽  
Vol 40 (2) ◽  
pp. 293 ◽  
Author(s):  
DR Eagling ◽  
RJ Sward ◽  
GM Halloran
Keyword(s):  
Leaf Area ◽  
Growth Rates ◽  
Barley Yellow Dwarf Virus ◽  
Dry Weight ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Root Dry Weight ◽  
Shoot Dry Weight ◽  
Barley Yellow Dwarf ◽  
Yellow Dwarf Virus

Measurements were made on the effect of barley yellow dwarf virus (BYDV) infection on the early growth of four commercial cultivars of ryegrass (Lolium spp.) under two different temperatures (24�C and 16�C). At 24'C, BYDV infection was associated with reduced root dry weight (30-40%) in all cultivars; the effect of infection on shoot dry weight and leaf area was variable. At 16�C, the effect of BYDV infection was variable, being associated with increases in root dry weight, shoot dry weight, and leaf area in one cultivar (Grasslands Ariki) and decreases in another (Victorian). In two other cultivars, root dry weight, shoot dry weight and leaf area were not significantly affected (P>0.05) by infection with BYDV.At 24�C, the reductions in root dry weight associated with BYDV infection were not concomitant with reductions in the root relative growth rates. Up to at least 28 days after inoculation (46-50 days after germination) reductions in root dry weight were associated with both aphid-feeding damage and virus infection. Experiments with the cultivar Victorian, showed that shoot dry weight was not significantly affected (P>0.05) by feeding with viruliferous (BYDV) or non-viruliferous aphids (Rhopalosiphum padi L.). At 16�C, changes in root and shoot dry weight were associated with changes in the root and shoot relative growth rates.

scholarly journals Dactylonectria and Ilyonectria Species Causing Black Foot Disease of Andean Blackberry (Rubus Glaucus Benth) in Ecuador

Diversity ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 218 ◽  
Author(s):  
Jessica Sánchez ◽  
Paola Iturralde ◽  
Alma Koch ◽  
Cristina Tello ◽  
Dennis Martinez ◽  
...  
Keyword(s):  
Elongation Factor ◽  
Morphological Characteristics ◽  
Translation Elongation ◽  
Disease Symptoms ◽  
Histone 3 ◽  
Dactylonectria Torresensis ◽  
Pathogenicity Tests ◽  
Foot Disease ◽  
Black Foot ◽  
Black Foot Disease

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.

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