Loofah [Luffa acutangula (L.) Roxb.] is grown in some regions of Asia, Africa and the Americas. This vegetable is well known for its high nutritional and medicinal value. Loofah plants showing typical symptoms of phytoplasma infection, such as witches’ broom, fruit deformation, flower proliferation and phyllody were observed in a commercial field in Sinaloa, Mexico, in January 2015. Nineteen symptomatic

Plasmodiophora brassicae causes clubroot on Brassica vegetables and canola around the world. A diverse assemblage of new pathotypes have been identified on canola in the Canadian province of Alberta since 2012, but the pathotypes present in the rest of Canada have not been assessed in detail in recent years. Brassica vegetable and canola fields in Ontario were surveyed for clubroot in 2017–2019. The

Symptoms of ringspots and vein-clearing were observed on wasabi (Wasabia japonica (Miq) Matsum) plants in three greenhouses in British Columbia during 2017. Ten indicator plant species, including four Nicotiana species, were inoculated with sap extracts from symptomatic leaves; after 4–11 days, necrotic lesions developed on all plants. Transmission electron microscopy revealed rod-shaped virions, 250–300 nm

Restrictions about the use of chemicals have limited the availability of control measures against plant-parasitic nematodes. The search for more sustainable approaches has focused the attention on biological control agents, such as Trichoderma species. In recent years, there has been a growing interest in the use of biopolymers for a wide range of applications. These polysaccharide-based compounds

Gray blight, caused by Pestalotiopsis-like species, is one of the most serious diseases in tea [Camellia sinensis (L.) O. Kuntze] production. In this study, eight Pestalotiopsis isolates obtained from diseased tea leaves collected in Chongqing, China were identified as P. chamaeropis Maharachch, K.D. Hyde & Crous. Pestalotiopsis chamaeropis as a causal agent of tea gray blight disease was clearly distinguished

(2020). Alberta Regional Meeting, 2019 / Réunion régionale de l’Alberta, 2019. Canadian Journal of Plant Pathology: Vol. 42, No. 3, pp. 445-452.

(2020). Atlantic regional meeting, 2019/Réunion régionale de l'Atlantique, 2019. Canadian Journal of Plant Pathology: Vol. 42, No. 3, pp. 453-457.

(2020). Southwestern Ontario regional meeting, 2019/Réunion régionale sud-ouest de l’Ontario, 2019. Canadian Journal of Plant Pathology: Vol. 42, No. 3, pp. 465-467.

Stemphylium leaf blight (SLB), caused by Stemphylium vesicarium (Wallr.) E.G. Simmons, has become an important disease of onion (Allium cepa L.) in Ontario, Canada, and the northeastern USA in recent years. The disease presents as elongated lesions on the leaves and severe leaf dieback. The effect on yield is unclear, but the extensive leaf dieback limits uptake of sprout inhibitors that are applied

Ornamental production systems are complicated to manage due to the many species and genera that may be grown and handled together on a single production site. Ornamentals are threatened by various phytopathogenic fungi in greenhouse and field production. Among these, Botrytis cinerea is one of the most notorious pathogens of ornamentals, specifically cut flowers. B. cinerea is responsible for causing

Smutted Bermudagrass (Cynodon dactylon L.) plants with diseased spikelets and completely deformed inflorescences covered with black teliospores were collected from five locations at the borders of plantations in Kafr El-Sheikh province, Egypt, in April 2018. The fungus was isolated from infected plants and identified as Ustilago cynodontis (Passerini) Henn. based on its cultural and morphological characteristics

Clubroot, a soil-borne disease caused by the obligate parasite Plasmodiophora brassicae Woronin, is a threat to canola (Brassica napus L.) production in western Canada. Genetic resistance represents the most effective tool to manage this disease. However, given the rapid spread of clubroot and the emergence of new virulent pathotypes of P. brassicae, it is important to accelerate the resistance breeding

Symptoms of partially bleached and completely white heads were observed in a triticale (× Triticosecale) cultivar ‘BARI Triticale 1ʹ in the research plots at the Regional Agricultural Research Station, Jashore, Bangladesh, during April 2019. Foliar symptoms with elliptical or eye-shaped lesions were also found on plant leaves. The main intention of this study was to isolate and identify the causal

Abstract Cannabis (Cannabis sativa L., marijuana) plants grown under greenhouse or controlled environments with symptoms of leaf yellowing, leaf necrosis and defoliation were observed during 2018–2019. Additional symptoms included crown rot and internal browning or blackening of the pith tissues. Stock (mother) plants as well as plants in the vegetative and flowering stages of 15 cannabis strains (genotypes)

The structure and diversity of wild grass spike-inhabiting Fusarium communities are not well understood. Fifteen common, non-cultivated grasses were surveyed across two years, regions, and land uses for spike-dwelling Fusarium spp. Eleven fungal species were identified from 857 isolates, including two, F. camptoceras and F. lactis, not recorded previously in New York state or on grass hosts. Species

Abstract Fusarium oxysporum causes root browning and crown infection on marijuana (Cannabis sativa L.) plants, resulting in stunted growth, yellowing of leaves, and plant death. Pathogen presence and diversity were assessed in samples of diseased crowns, stems, pith tissues and roots from five commercial production facilities in British Columbia and Ontario. PCR of the elongation factor (EF-1 α) region

Phytoplasmas are a major liming factor to the growth and production of many plant species worldwide. Most studies have used the conserved 16S rRNA gene for phytoplasma identification and classification. The efficiency of the tuf and secA genes length in the characterization of phytoplasmas was evaluated by designing universal primers to amplify the long and short tuf (740 bp and 414 bp) and secA (1232

Rhizomania is one of the most damaging and widespread diseases in the major sugar beet (Beta vulgaris L. subsp. vulgaris) growing regions worldwide. The causal agent, Beet necrotic yellow vein virus, is transmitted by a plasmodiophorid vector, Polymyxa betae Keskin. In this study, the inhibition of BNYVV multiplication was evaluated, under field conditions, in six sugar beet transgenic events generated

Fusarium species cause various diseases of tomato, the most common being vascular wilt and cortical rots. A study was carried out to characterize Fusarium spp. found in the stems of wilted tomato plants from farms in Mwea West Sub-county, Kirinyaga County, Kenya. Isolates were collected from tomato stems showing vascular discolouration. One hundred and one isolates of Fusarium spp. were obtained and

Root-knot nematodes are responsible for substantial losses in rice production. These parasites are difficult to control, particularly in flooded fields, which require carefully designed strategies to avoid contamination of water bodies. This study investigated whether biotic and abiotic elicitors can induce resistance to the root-knot nematode Meloidogyne graminicola in rice plants. An initial screening

Black rot, caused by Xanthomonas campestris pv. campestris (Pammel) Dowson (Xcc), is a devastating disease of cruciferous crops worldwide and a threat to the economic production of Brassica oleracea L. in China. Strategies to control this disease are limited. In addition, knowledge of the molecular mechanisms of pathogenicity and host resistance are still only poorly understood. In this study, we performed

Hybrid wheat shows promise to increase yield potential, but many questions remain about the hybrid system. One of the most important is how hybrids will perform in terms of diseases such as Fusarium head blight (FHB). It is unknown if a hybrid produced from a resistant by susceptible cross will express acceptable resistance levels. This experiment tested hybrids produced from four resistant parents

Abstract In two glasshouse experiments, colonization of potato (Solanum tuberosum L.) plants by the bacterial pathogens Dickeya solani and Pectobacterium parmentieri was studied after leaf infection. Leaves, whether or not artificially wounded, were spray-inoculated with various densities of green-fluorescent protein tagged strains of the pathogens, avoiding contamination of soil during inoculation

Powdery mildew on wasabi (Wasabia japonica (Miq.) Matsumura)plants reduces photosynthesis and severe infections can result in chlorosis and defoliation, resulting in reduced yields. Erysiphe cruciferarum Opiz ex L. Junell was confirmed as the causal agent using sequence analysis of the ITS1-5.8 S-ITS2 region, along with conidial and conidiophore morphology. To evaluate reduced-risk management options

Common bean (Phaseolus vulgaris L.) can be affected by several viral diseases, including golden mosaic caused by the Bean golden mosaic virus (BGMV). When infected by BGMV, bean plants undergo major physiological changes, leading to a reduction or complete loss of productivity. This study aimed to evaluate and compare seven bean cultivars and lineages, as well as the legume calopo (Calopogonium mucunoides

Clubroot of canola (Brassica napus L.), caused by Plasmodiophora brassicae Woronin, has spread to more than 3000 fields in Alberta, Canada, since it was first identified in 2003, but the disease had not been reported in the Peace Country Region in the northwest of the province. In 2017, 21 cases of clubroot were found in Big Lakes County, the southeastern-most district in this region. In 2018, an additional

This study aimed to evaluate the antifungal activity of oregano and clove essential oils and their main components (thymol, carvacrol and eugenol) against Penicillium digitatum, as well as against isolates of Penicillium italicum and Geotrichum candidum resistant to imazalil or guazatine, respectively. In vitro tests were conducted by a direct contact method on potato dextrose agar medium. The results

Abstract The objective of this study was to assess harvested dried inflorescences (buds) of cannabis (Cannabis sativa L., marijuana) for fungal presence and diversity. Samples from drying rooms of three licenced facilities in British Columbia were tested repeatedly during 2017–2019. A swab method was used, wherein sterile cotton swabs were gently swabbed over bud surfaces and directly streaked onto

(2020). British Columbia regional meeting, 2019 / Réunion régionale de la Colombie-Britannique, 2019. Canadian Journal of Plant Pathology: Vol. 42, No. 3, pp. 458-464.

Brown spot, caused by Septoria glycines Hemmi, is a highly prevalent foliar disease of soybean (Glycine max (L.) Merr.). Despite its wide distribution, the development of Septoria brown spot and its relationship with yield reduction remain poorly characterized. In this study, we conducted replicated multi-location inoculated field trials to characterize the disease development and evaluated the relationship

Downy mildew caused by Plasmopara viticola is a devastating disease of grapes. Four formae speciales have been identified in the pathogen, with P. viticola f. sp. aestivalis and P. viticola f. sp. riparia responsible for epidemics in eastern Canada. The objective of this study was to evaluate the effect of temperature on zoospore release from sporangia and the aggressiveness of these two formae speciales

In 2014, 2000 plants showing root rot symptoms were collected from 200 commercial soybean (Glycine max L.) fields in South Dakota, USA. One thousand one hundred thirty fungal isolates obtained from the samples were identified as Fusarium species by morphology and sequencing of the translation elongation factor 1-alpha gene. Fifty-one percent were F. graminearum, 30.0% were F. acuminatum, 8.0% belonged

Apple replant disease (ARD) occurs frequently in old orchards and is an important disease that limits apple production in China. Fusarium oxysporum is one of the causal agents of ARD and its pathogenic mechanism is still unclear. To explore the potential pathogenesis-related genes of this pathogen, a T-DNA insertion library of F. oxysporum HS2 was constructed via optimized Agrobacterium tumefaciens-mediated

Stem rust, caused by Puccinia graminis, is a catastrophic disease that has and continues to cause yield losses in barley, oat, and wheat crops worldwide. Use of host resistance genes is the most economic, efficient, and environmentally best method to control the disease. Resistance genes have been incorporated into most commercial cultivars and have been effective, for races in the North American populations

Powdery mildew, caused by Podosphaera xanthii (U. Braun & Shishkoff), is a widespread disease on greenhouse cucumber in many countries, including Canada. The efficacy of seven biological or chemical products to manage powdery mildew was evaluated. These included Rhapsody® (Bacillus subtilis Ehrenberg strain QST 713), Microflora PROTM (B. subtilis, Bacillus amyloliquefaciens Priest et al., Bacillus

Fusarium solani and F. tricinctum are important root rot pathogens of soybean in the northern Great Plains of North America. The role of temperature on their growth was investigated in vitro at temperatures between 0 to 35ºC, while disease development in the soybean cultivar ‘Barnes’ was tested at 15°C, 20°C, 25°C and 30°C using several methods over 1 to 4 weeks. All experiments were conducted in a

(2020). Correction. Canadian Journal of Plant Pathology. Ahead of Print.

Setosphaeria turcica causes Northern corn leaf blight (NCLB). In this study, 92 isolates of S. turcica were collected from naturally infected corn fields at 57 sites within China to determine physiological race composition and genetic diversity. Based on the reaction of differential hosts, isolates were divided into 14 physiological races (0, 1, 2, 12, 3, 13, 23, N, 1N, 2N, 3N, 13N, 23N, 123N). Races

Several virus diseases cause damage to Vitis vinifera L., but information on their incidence and impact on hybrid cultivars is scarce, particularly under cool-climate conditions. In Nova Scotia (NS), the wine industry is based predominantly on interspecific hybrid cultivars. To understand the occurrence of major grapevine viruses in NS, surveys were conducted in 2016, 2017 and 2018. A total of 965

A severe branch dieback and canker was observed on black walnut (Juglans nigra L.) in Yili county, Xinjiang, China, during the spring and summer, 2016. A fungus was consistently isolated from infected branches. Pathogenicity tests showed that the fungus could infect branches, and produced the same symptoms under artificial inoculation conditions as those observed in the field. The fungus was identified

The presence of well-defined and depressed circular leaf spots, dark in their core and surrounded by a light brown dim halo, was observed on Dendrobium nobile plants in the municipality of Ixtaczoquitlán, state of Veracruz, Mexico, in 2019. Colletotrichum isolates were consistently obtained from symptomatic plants of D. nobile. The morphological characteristics of these isolates resembled each other

Root rot is a concern in the pea growing areas of Canada and elsewhere in the world, since it can cause significant yield loss. Fusarium spp. are considered major pea root rot pathogens. In this study, the pathogenicity and host range of Fusarium species collected from earlier surveys of commercial pea fields in Alberta were evaluated. Forty-five isolates belonging to six Fusarium species were selected

A shift to larger farms, bigger equipment and reduced crop diversity has been occurring in North American agriculture for many years. This has resulted in an increased reliance on genetic resistance and pesticides because much of the pest reduction from natural biological control (ecosystem services) associated with crop rotation and biological diversity has been lost. This shift has contributed to

Wheat leaves infected with Puccinia triticina, the causal agent of wheat leaf rust, were collected from across Canada in 2014. From these leaves, 102 single-pustule isolates were recovered and tested for virulence on 16 standard differential wheat lines, with 28 unique virulence phenotypes found. The most common were TBDG (16.7%), TBBG (13.7%), MLPS and TNBG (both at 7.8%). Most isolates (95) originated

Blackleg, caused by Leptosphaeria maculans, is a serious disease on canola or rapeseed in Canada, Australia and Europe. Disease levels have increased in western Canada recently and additional tools are needed to improve blackleg management. Seed treatment can be a cost-effective approach against blackleg, but there is currently no registered seed-treatment product targeting aboveground blackleg infection

Wild soybean (Glycine soja) is the ancestor of cultivated soybean (Glycine max). Soybean mosaic virus (SMV) is an important pathogen affecting soybean production worldwide. The effect of exogenous salicylic acid (SA) application on the disease resistance of wild soybean plants infected with SMV is still unclear. In this study, we determined the SA content; reactive oxygen species (ROS) content; lipid

Hosta virus X (HVX) is the most economically significant virus infecting hosta (Hosta spp.) plants worldwide, and has been reported from North America, Europe, Asia and Oceania. In May 2019, various viral-like disease symptoms were observed on hosta plants in a park in Harbin City in Northeast China, and infection by HVX was confirmed by small RNA sequencing, RT-PCR and electron microscopy. The infectivity

Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is an important disease in China. In this study, airborne spore concentrations were monitored using spore samplers and real-time PCR during 2013– 2015 at three locations in Gangu, Gansu province of China. The effects of meteorological variables on spore concentration were analyzed and models were developed for forecasting dynamics

Soybean (Glycine max) is an annual leguminous plant that has been cultivated in China for over 4500 years. During a survey conducted in 2018, collar rot was observed in soybean crops in Zhangzhou, Fujian Province, China. The disease first appeared as water-soaked lesions on the surface of the stems, followed by the development of large decayed areas with abundant white mycelium. A fungus was isolated

Clubroot is an important root disease of canola/oilseed rape (Brassica napus L.) caused by Plasmodiophora brassicae. To cope with the emergence of new virulent pathotypes of P. brassicae that threaten canola production in western Canada, there is a need to identify novel sources of resistance for breeding programmes. In the present study, a series of nine B. napus genotypes, from different geographic

(2020). Outstanding Young Scientist Award. Canadian Journal of Plant Pathology: Vol. 42, No. 1, pp. 144-145.

The abaca (Musa textilis Nee) is an important fibre crop in the Philippines. Its fibre yield and quality is severely impacted by two potyviruses, namely, banana bract mosaic virus (BBrMV) and sugarcane mosaic virus (SCMV). A multiplex RT-PCR assay was developed for the simultaneous detection of these two RNA viruses in abaca. Primer sets were designed to amplify fragments of BBrMV coat protein (743 bp)

Fusarium head blight (FHB) and the associated mycotoxin deoxynivalenol (DON) negatively impact the wheat industry worldwide. In North America, FHB is mainly caused by Fusarium graminearum sensu stricto. The purpose of this study was to evaluate, under storage conditions, the expression of the DON biosynthetic gene trichodiene synthase (Tri5) of F. graminearum in grain of hard red winter wheat cultivars

In recent years, there has been an increase in the frequency of Cercospora beticola (Sacc.), the cause of Cercospora leaf spot (CLS) in sugarbeet (Beta vulgaris L.), isolates with demethylase inhibitor (DMI) and quinone outside inhibitor (QoI) fungicide resistance collected from commercial fields in Michigan, USA and Ontario, Canada. This study evaluated sensitivity distributions of C. beticola populations

(2020). Outstanding Research AwardThe Canadian Phytopathological SocietyPrix Excellence en rechercheLa Société canadienne de phytopathologie. Canadian Journal of Plant Pathology: Vol. 42, No. 1, pp. 146-148.

(2020). Outstanding Research AwardThe Canadian Phytopathological Society Prix Excellence en rechercheLa Société canadienne de phytopathologie. Canadian Journal of Plant Pathology: Vol. 42, No. 1, pp. 142-143.

(2020). FellowThe Canadian Phytopathological SocietyMembre associéLa Société canadienne de phytopathologie. Canadian Journal of Plant Pathology: Vol. 42, No. 1, pp. 140-141.

Passiflora edulis plants with typical symptoms of begomovirus infection, including leaf curling and dark green, swollen veins, were discovered in Yunnan province, China. The full-length viral components and satellite molecules of the infected P. edulis plants were obtained by enrichment of circular DNA by rolling circle amplification, restriction enzyme digestion, cloning and DNA sequencing. The viral

Anthracnose was observed on postharvest avocados (Persea americana) in a commercial market in Jinju, South Korea, in 2019. Symptoms included soft rot and sunken lesions leaking necrotic fluid. Orange conidial masses were observed on the outer surfaces of these unappealing avocados. Colletotrichum fungi producing grey to olive colonies with orange conidial masses were consistently recovered from the

Aphanomyces euteiches is an important root pathogen of several legume and forage crops worldwide. Disease management is challenging due to resilient oospores that can persist in the soil for long periods of time. Several research groups are working towards incorporating disease resistance into crop cultivars involving large-scale disease resistance screening and, for some crops, the use of molecular