scholarly journals First Report of Phytophthora capsici Causing Wilting and Root and Crown Rot on Capsicum annuum (Bell Pepper) in Ecuador

Plant Disease ◽  
2020 ◽  
Vol 104 (7) ◽  
pp. 2032-2032 ◽  
Author(s):  
Jefferson Bertin Vélez-Olmedo ◽  
Luis Saltos ◽  
Liliana Corozo ◽  
Bianca Samay Bonfim ◽  
Sergio Vélez-Zambrano ◽  
...  
Keyword(s):  
Capsicum Annuum ◽  
Phytophthora Capsici ◽  
Bell Pepper ◽  
Crown Rot ◽  
First Report ◽  
Root And Crown Rot

scholarly journals First Report of Phytophthora capsici Infection on Bell Peppers (Capsicum annuum L.) from Punjab, Pakistan

2018 ◽  
Vol 7 (1) ◽  
pp. 51-51
Author(s):  
Sajjad Hyder ◽  
Muhammad Inam-ul-Haq ◽  
Raees Ahmed ◽  
Amjad S. Gondal ◽  
Nida Fatima ◽  
...  
Keyword(s):  
Capsicum Annuum ◽  
Irrigation System ◽  
Phytophthora Capsici ◽  
Bell Pepper ◽  
Fluorescent Light ◽  
Phytophthora Blight ◽  
Seedling Mortality ◽  
Canal Irrigation ◽  
First Report ◽  
Capsicum Annuum L

Bell pepper (Capsicum annuum L.) is one of the extensively cultivated vegetable crop in Punjab, Pakistan. During two years of field surveys, February-November 2016-17, damping off and blight symptoms were observed. Average seedling mortality was recorded as 18.7% while yield loss due to blight was estimated 32 to 41% at mature stages. Maximum blight infection was recorded from the areas frequently flooded with canal irrigation system. At early stages, lesions were noticed on stem portions at soil line level while at crop maturity stages blight symptoms were noted. Leaves were blanched and wilted while fruits were covered with white mold. Masses of sporangia were evident on and inside the infected fruits under humid conditions. A total of twelve isolates were recovered from infected root, stem and fruit portions on rye agar media (Caten and Jinks, 1968) incubated at 25oC under fluorescent light. Papillated sporangia were averaged 42 ± 2.6 X 27 ± 1.7 μm in size (range 27 - 52 × 23 - 36 μm). Oospores were produced on 20% V8 agar and were spherical 22 ± 1.4 μm in diameter (range 14 to 27 μm) while average pedicels length was recorded as 58 ± 12.5 μm (range 13 to 120 μm). These observations were similar to those described for P. capsici (Cocoa, 1988). DNA was extracted using Cetyl Trimethylammonium Bromide (CTAB) method and the internal transcribed spacer regions (ITS1 and ITS2) were amplified by polymerase chain reaction (White et al., 1990). The amplicons were purified and sequenced in both directions (GenBank Accession No. MF322868 and MF322869). BLAST analysis revealed these isolates showed 99% identity with ITS sequences of Phytophthora capsici (KM369964 and KU518782). Pathogenicity assay was performed on healthy bell pepper seedlings with five repeats. Soil was flooded with 20ml sporangial suspension (1 x 103 sporangia/ml) in pots containing seedlings while 5ml suspension was sprayed until run off on mature plants (Hyder et al., 2018). A set of uninoculated seedlings was used as control. Pots were kept in dew chamber for 10-20 days at 25±2 oC. Seedling mortality was observed five days after inoculation while at later stage plants develop brown-to-black stem lesions with white mycelial growth on leaves. These symptoms were identical to the P. capsici infections in field. Consistent re-isolations of P. capsici confirm its association with the disease. To our knowledge, this is the first report of Phytophthora blight on bell pepper from Pakistan

scholarly journals First Report of Crown and Root Rot Caused by Phytophthora capsici on Hydroponically Grown Cucumbers in Norway

Plant Disease ◽  
2008 ◽  
Vol 92 (7) ◽  
pp. 1138-1138 ◽  
Author(s):  
M. L. Herrero ◽  
M. B. Brurberg ◽  
A. Hermansen
Keyword(s):  
Mating Type ◽  
Phytophthora Capsici ◽  
Crown Rot ◽  
Yield Reduction ◽  
Cox1 Gene ◽  
Pathogenicity Test ◽  
Internal Transcribed Spacer Region ◽  
First Report ◽  
Leaf Stage ◽  
Root And Crown Rot

In December 2004, symptoms of root and crown rot were observed on cucumbers (Cucumis sativus L.) in a greenhouse in Norway. Cucumbers were the only crop of the greenhouse that used rockwool as a growing substrate in a hydroponical system. The first symptoms were detected in propagation material. One week after planting, symptoms of root and crown rot were observed and approximately 10% of the plants died. Later, losses of 50% in some greenhouses were observed. A yield reduction as much as 65% was estimated in the winter period (January and February). The two main cucumber cultivars planted were Armada and Lopez. In February 2005, Phytophthora capsici (Leonian) (1) was isolated on potato dextrose agar from a sample of cv. Lopez. The isolate produced deciduous, papillate sporangia (occasionally with two or three papilla) and pedicels that were sometimes longer than the sporangia. Sequencing of amplicons of the internal transcribed spacer region (ITS) rDNA and of the mitochondrial cytochrome c oxidase subunit 1 (Cox1) gene (2) confirmed the identification. Three isolates collected through 2005 from the same greenhouse were crossed with tester strains of P. cryptogea. Formation of oogonia and amphigynous antheridia was always observed in crosses with mating type A2; thus, all isolates were the A1 mating type. All three isolates grew well at 35°C and did not produce chlamydospores. A pathogenicity test was performed with one isolate of P. capsici. Four plants of cucumber cvs. Indira and Jessica were grown in a growth chamber at 24°C. Plants at the two-leaf stage were drenched with 20 ml of a zoospore suspension of 106 zoospores per ml per plant. After 18 days, all plants of both cultivars developed symptoms of crown rot or wilted and died. P. capsici was reisolated from inoculated plants of both cultivars. The pathogenicity test was repeated in the same way, but in a greenhouse with temperatures that ranged between 18 and 29°C. In addition, four plants of both cultivars at the four-leaf stage were inoculated with a suspension of 105 zoospores per ml. After 1 week, all plants developed crown rot or were irreversibly wilted, independently of the plant age or the zoospore concentration. To our knowledge, this is the first report of P. capsici in Norway. References: (1) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. The American Phytopathological Society St. Paul MN, 1996. (2) L. P. N. M. Kroon et al. Phytopathology 94:613, 2004.

scholarly journals Interactions of Phytophthora capsici with Resistant and Susceptible Pepper Roots and Stems

2015 ◽  
Vol 105 (10) ◽  
pp. 1355-1361 ◽  
Author(s):  
Amara R. Dunn ◽  
Christine D. Smart
Keyword(s):  
Green Fluorescent Protein ◽  
Host Resistance ◽  
Fluorescent Protein ◽  
Phytophthora Capsici ◽  
Bell Pepper ◽  
Crown Rot ◽  
Root And Crown Rot ◽  
Green Fluorescent ◽  
Secondary Roots ◽  
New Cultivars

Using host resistance is an important strategy for managing pepper root and crown rot caused by Phytophthora capsici. An isolate of P. capsici constitutively expressing a gene for green fluorescent protein was used to investigate pathogen interactions with roots, crowns, and stems of Phytophthora-susceptible bell pepper ‘Red Knight’, Phytophthora-resistant bell pepper ‘Paladin’, and Phytophthora-resistant landrace Criollos de Morelos 334 (CM-334). In this study, the same number of zoospores attached to and germinated on roots of all cultivars 30 and 120 min postinoculation (pi), respectively. At 3 days pi, significantly more secondary roots had necrotic lesions on Red Knight than on Paladin and CM-334 plants. By 4 days pi, necrotic lesions had formed on the taproot of Red Knight but not Paladin or CM-334 plants. Although hyphae were visible in the crowns and stems of all Red Knight plants observed at 4 days pi, hyphae were observed in crowns of only a few Paladin and in no CM-334 plants, and never in stems of either resistant cultivar at 4 days pi. These results improve our understanding of how P. capsici infects plants and may contribute to the use of resistant pepper cultivars for disease management and the development of new cultivars.

scholarly journals First Report of Neopestalotiopsis clavispora Causing Root and Crown Rot on Strawberry in Italy

Plant Disease ◽  
2019 ◽  
Vol 103 (11) ◽  
pp. 2959-2959 ◽  
Author(s):  
G. Gilardi ◽  
F. Bergeretti ◽  
M. L. Gullino ◽  
A. Garibaldi
Keyword(s):  
Crown Rot ◽  
First Report ◽  
Root And Crown Rot

scholarly journals First Report of Phytophthora citrophthora on Penstemon barbatus in Italy

Plant Disease ◽  
2006 ◽  
Vol 90 (9) ◽  
pp. 1260-1260 ◽  
Author(s):  
A. Garibaldi ◽  
D. Bertetti ◽  
D. Minerdi ◽  
M. L. Gullino
Keyword(s):  
Its Region ◽  
The United States ◽  
Phytophthora Species ◽  
Crown Rot ◽  
Pathogenicity Test ◽  
Phytophthora Citrophthora ◽  
First Report ◽  
Blastn Analysis ◽  
Root And Crown Rot ◽  
Pathogenicity Tests

Penstemon barbatus (Cav.) Roth (synonym Chelone barbata), used in parks and gardens and sometimes grown in pots, is a plant belonging to the Scrophulariaceae family. During the summers of 2004 and 2005, symptoms of a root rot were observed in some private gardens located in Biella Province (northern Italy). The first symptoms resulted in stunting, leaf discoloration followed by wilt, root and crown rot, and eventually, plant death. The diseased tissue was disinfested for 1 min in 1% NaOCl and plated on a semiselective medium for Oomycetes (4). The microorganism consistently isolated from infected tissues, grown on V8 agar at 22°C, produced hyphae with a diameter ranging from 4.7 to 5.2 μm. Sporangia were papillate, hyaline, measuring 43.3 to 54.4 × 26.7 to 27.7 μm (average 47.8 × 27.4 μm). The papilla measured from 8.8 to 10.9 μm. These characteristics were indicative of a Phytophthora species. The ITS region (internal transcribed spacer) of rDNA was amplified using primers ITS4/ITS6 (3) and sequenced. BLASTn analysis (1) of the 800 bp obtained showed a 100% homology with Phytophthora citrophthora (R. & E. Sm.) Leonian. The nucleotide sequence has been assigned GenBank Accession No. DQ384611. For pathogenicity tests, the inoculum of P. citrophthora was prepared by growing the pathogen on autoclaved wheat and hemp kernels (2:1) at 25°C for 20 days. Healthy plants of P. barbatus cv. Nano Rondo, 6 months old, were grown in 3-liter pots (one plant per pot) using a steam disinfested substrate (peat/pomix/pine bark/clay 5:2:2:1) in which 200 g of kernels per liter of substrate were mixed. Noninoculated plants served as control treatments. Three replicates were used. Plants were maintained at 15 to 20°C in a glasshouse. The first symptoms, similar to those observed in the gardens, developed 21 days after inoculation, and P. citrophthora was consistently reisolated from infected plants. Noninoculated plants remained healthy. The pathogenicity test was carried out twice with similar results. A nonspecified root and crown rot of Penstemon spp. has been reported in the United States. (2). To our knowledge, this is the first report of P. citrophthora on P. barbatus in Italy as well as in Europe. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997 (2) F. E. Brooks and D. M. Ferrin. Plant Dis. 79:212, 1995. (3) D. E. L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997. (4) H. Masago et al. Phytopathology 67:425, 1977.

scholarly journals First Report of Mesocriconema sphaerocephalum (Taylor, 1936) Loof, 1989 Associated with Bell Pepper (Capsicum annuum) in Egypt

2020 ◽  
Vol 19 (1) ◽  
pp. 19-28
Author(s):  
Zafar Handoo ◽  
Mihail Kantor ◽  
Mostafa Hammam ◽  
Moawad Mohamed ◽  
Mahfouz Abdel Gawad
Keyword(s):  
Capsicum Annuum ◽  
Bell Pepper ◽  
First Report

scholarly journals First report of Fusarium commune causing root and crown rot on maize in Italy

Plant Disease ◽  
2021 ◽  
Author(s):  
Monica Mezzalama ◽  
Vladimiro Guarnaccia ◽  
Ilaria Martino ◽  
Giulia Tabome ◽  
Maria Lodovica GULLINO
Keyword(s):  
Plant Disease ◽  
Tap Water ◽  
Morphological Characteristics ◽  
Plant Diseases ◽  
Crown Rot ◽  
Conidial Suspension ◽  
Fusarium Spp ◽  
First Report ◽  
Root And Crown Rot ◽  
Pathogenicity Tests

Maize (Zea mays L.) is a cereal crop of great economic importance in Italy; production is currently of 62,587,469 t, with an area that covers 628,801 ha, concentrated in northern Italy (ISTAT 2020). Fusarium species are associated with root and crown rot causing failures in crop establishment under high soil moisture. In 2019 maize seedlings collected in a farm located in San Zenone degli Ezzelini (VI, Italy) showed root and crown rot symptoms with browning of the stem tissues, wilting of the seedling, and collapsing due to the rotting tissues at the base of the stem. The incidence of diseased plants was approximately 15%. Seedlings were cleaned thoroughly from soil residues under tap water. Portions (about 3-5 mm) of tissue from roots and crowns of the diseased plants were cut and surface disinfected with a water solution of NaClO at 0.5% for 2 minutes and rinsed in sterile H20. The tissue fragments were plated on Potato Dextrose Agar (PDA) amended with 50 mg/l of streptomycin sulfate and incubated for 48-72 hours at 25oC. Over the 80 tissue fragments plated, 5% were identified as Fusarium verticillioides, 60% as Fusarium spp., 35% developed saprophytes. Fusarium spp. isolates that showed morphological characteristics not belonging to known pathogenic species on maize were selected and used for further investigation while species belonging to F. oxysporum were discarded. Single conidia of the Fusarium spp. colonies were cultured on PDA and Carnation Leaf Agar (CLA) for pathogenicity tests, morphological and molecular identification. The colonies showed white to pink, abundant, densely floccose to fluffy aerial mycelium. Colony reverse showed light violet pigmentation, in rings on PDA. On CLA the isolates produced slightly curved macronidia with 3 septa 28.1 - 65.5 µm long and 2.8-6.3 µm wide (n=50). Microconidia were cylindrical, aseptate, 4.5 -14.0 µm long and 1.5-3.9 µm wide (n=50). Spherical clamydospores were 8.8 ± 2.5 µm size (n=30), produced singly or in pairs on the mycelium, according to the description by Skovgaard et al. (2003) for F. commune. The identity of two single-conidia strains was confirmed by sequence comparison of the translation elongation factor-1α (tef-1α), and RNA polymerase II subunit (rpb2) gene fragments (O’Donnell et al. 2010). BLASTn searches of GenBank, and Fusarium-ID database, using the partial tef-1α (MW419921, MW419922) and rpb2 (MW419923, MW419924) sequences of representative isolate DB19lug07 and DB19lug20, revealed 99% identity for tef-1α and 100% identity to F. commune NRRL 28387(AF246832, AF250560). Pathogenicity tests were carried out by suspending conidia from a 10-days old culture on PDA in sterile H2O to 5×104 CFU/ml. Fifty seeds were immersed in 50 ml of the conidial suspension of each isolate for 24 hours and in sterile water (Koch et al. 2020). The seeds were drained, dried at room temperature, and sown in trays filled with a steamed mix of white peat and perlite, 80:20 v/v, and maintained at 25°C and RH of 80-85% for 14 days with 12 hours photoperiod. Seedlings were extracted from the substrate, washed under tap water, and observed for the presence of root and crown rots like the symptoms observed on the seedlings collected in the field. Control seedlings were healthy and F. commune was reisolated from the symptomatic ones and identified by resequencing of tef-1α gene. F. commune has been already reported on maize (Xi et al. 2019) and other plant species, like soybean (Ellis et al. 2013), sugarcane (Wang et al. 2018), potato (Osawa et al. 2020), indicating that some attention must be paid in crop rotation and residue management strategies. To our knowledge this is the first report of F. commune as a pathogen of maize in Italy. References Ellis M L et al. 2013. Plant Disease, 97, doi: 10.1094/PDIS-07-12-0644-PDN. ISTAT. 2020. http://dati.istat.it/Index.aspx?QueryId=33702. Accessed December 28, 2020. Koch, E. et al. 2020. Journal of Plant Diseases and Protection. 127, 883–893 doi: 10.1007/s41348-020-00350-w O’Donnell K et al. 2010. J. Clin. Microbiol. 48:3708. https://doi.org/10.1128/JCM.00989-10 Osawa H et al. 2020. Journal of General Plant Pathology, doi.org/10.1007/s10327-020-00969-5. Skovgaard K 2003. Mycologia, 95:4, 630-636, DOI: 10.1080/15572536.2004.11833067. Wang J et al. 2018. Plant Disease, 102, doi/10.1094/PDIS-07-17-1011-PDN Xi K et al. 2019. Plant Disease, 103, doi/10.1094/PDIS-09-18-1674-PDN

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