Rhizoctonia stem canker and black scurf are among the most important diseases associated with pot... more Rhizoctonia stem canker and black scurf are among the most important diseases associated with potato (Solanum tuberosum L.) cultivation worldwide. Pathogenicity test of 19 isolates of Rhizoctonia solani Kühn obtained from four governorates in Syria revealed that isolates varied in their ability to cause disease with the isolate Rh15 being the most virulent in the development of the disease on potato plant under artificial infection. The relative susceptibility of seven commercial and local potato cultivars against R. solani was tested. The evaluation was based on black scurf severity and the negative impact of the disease on plant growth and expected effect on yield. The tested cultivars showed variable degrees of black scurf severity and consequent plant growth, but no completely immune cultivars were observed. Based on disease index (DI), potato varieties 'Agria', 'Ultra' and 'Labella' were highly susceptible to the disease; 'Spunta' was moderately resistant whereas 'Everest' was the most tolerant. Infection of the most susceptible cultivar "Afamia" resulted in the death of a large number of seedlings, large and deep canker on stems, with no formation of new tubers. Although 'Synergy' was moderately susceptible, and the black scurf incidence was higher than that of 'Everest' and 'Spunta', the loss of tubers weight was not significant compared to the previous two cultivars. The results suggested that use of tolerant and moderately resistant cultivars in Syria may help in reducing the development of black scurf on potatoes.
Archives of Phytopathology and Plant Protection, Oct 26, 2021
Abstract Crown and root rot of wheat is considered as one of the most damaging diseases, resultin... more Abstract Crown and root rot of wheat is considered as one of the most damaging diseases, resulting in significant yield losses in different regions worldwide. The aim of this study was to isolate and identify Fusarium species associated with crown rot of wheat in Syrian coastal areas. Ten Fusarium isolates were recovered from crowns and roots of durum wheat plants (var. Cham5), showing typical symptoms, collected from five different sites in coastal Tartous province. Based on morphological characteristics, 7 isolates were identified as F. incarnatum (syn. F. semitectum), and 3 isolates were F. solani. The sequencing of a partial TEF1-α gene of two representative isolates of these two species confirmed the morphological identification. Phylogenetic tree of partial TEF1-α gene showed a clear separation between the two species and high genetic similarity of Syrian and reference isolates. Up to our knowledge, this is the first report of F. incarnatum and F. solani infecting the roots and crowns of wheat in Syria.
Hamzeh, S., W. Naffaa and M.F. Azmeh. 2022. Occurrence of the Hyperparasite Ampelomyces quisquali... more Hamzeh, S., W. Naffaa and M.F. Azmeh. 2022. Occurrence of the Hyperparasite Ampelomyces quisqualis on Golovinomyces neosalviae (Erysiphaceae), Causal Agent of Powdery Mildew on Common Sage (Salvia officinalis). Arab Journal of Plant Protection, 40(2): 158-163. https://doi.org/10.22268/AJPP-040.2.158163 Ampelomyces quisqualis, the oldest mycoparasite of powdery mildew (PM), has been widely studied due to its potential in biocontrol. Many strains of this hyperparasite have been experimented worldwide and some of them were successfully applied for biocontrol, but others have been less efficient. No previous identification of Ampelomyces strains has been done in Syria, but some isolates were morphologically identified in the coastal region. There was no indication of Ampelomyces occurrence in any other location in Syria. During this three years survey (2019–2021), 73 plant samples were collected from five governorates, including coastal and southern regions in Syria. Ampelomyces pycnidi...
Powdery mildew caused by Erysiphe necator, is one of the most economically damaging diseases of g... more Powdery mildew caused by Erysiphe necator, is one of the most economically damaging diseases of grapevine throughout the world. This study aimed to identify the mating types of this pathogen in Syria using molecular markers. Three DNA extraction methods: Promega Kit, phenol chloroform isoamyl alcohol (PCI) and SDS were compared. The amount and quality of DNAs obtained by the SDS method were suitable for PCR amplification and other molecular assays. PCR amplification using specific primers (Uncin 144 and Uncin 511) was performed and the expected amplicon of 300-400 bp was obtained from 29 isolates of E. necator collected from different geographical locations and from different grapevine cultivars. Results obtained showed that E. necator may cause atypical symptoms similar to those of downy mildew, in some grapevine cultivars according to the environmental conditions and training system used. Isolates of E. necator were classified into four groups according to geographical locations a...
Abou Al-Fadil T., Naffaa W., Abou Fakher T., Muzher B. and Amer H. 2010. Apple Stem Canker Diseas... more Abou Al-Fadil T., Naffaa W., Abou Fakher T., Muzher B. and Amer H. 2010. Apple Stem Canker Disease in Sweida: the Causal Fungus and the Susceptibility of Some Apple Varieties to the Disease. Arab Journal of Plant Protection. 28(1), 16-19. Efforts to identify the causal organism of apple stem canker were carried out. Samples were taken from 25 apple trees showing symptoms of stem canker at five different geographical locations of Daher Al jabal area in Sweida to isolate and identify the causal organism. Results showed that more than 90% of the isolates were Alternaria alternate (Fries) Keissler. This pathogen was able to induce canker symptoms on stems of 12 apple varieties under artificial inoculation conditions. Isolates from different geographical sites differed in their pathogenicity. Apple varieties tested showed also significant differences in their susceptibility to the disease. Wealthy double red and Starking delicious varieties were the least susceptible, while Golden lody was the most susceptible to Alternaria canker disease.
Crown and collar rot of apple trees is a destructive and widespread disease in most areas of the ... more Crown and collar rot of apple trees is a destructive and widespread disease in most areas of the world. Surveys have been done to describe disease symptoms, estimate the disease incidence, and identify the pathogens associated with this disease in southern Syria. Disease incidence was 0.08 – 10 % in most studied sites, only in Alroom location it was up to 14.7 % in 2014 and 17.8 % in 2015, with average of 11.8 %. Symptoms included small pale green leaves, sparse foliage, and a reddish-brown discoloration of inner bark of the infected area at the base of infected tree. The isolated fungi belonged to genera and form genera Phytophthora, Rosellinia, Rhizoctonia, Phialophora, Acremonium, Pestalotiopsis, Cylindrocarpon and Verticillium. Phytophthora was isolated from all infected trees, and was the most frequent pathogen (53.7 % of total isolates). Phytophthora isolates recovered from crown cankers of apple were identified as P. cactorum (91.5 %) and P. cambivora (8.5 %). The results of ...
Anise (Pimpinella anisum L.) is an important medicinal spice plant that belongs to the family Api... more Anise (Pimpinella anisum L.) is an important medicinal spice plant that belongs to the family Apiaceae. Anise seeds are rich in essential oils and this is a reason why anise production in Serbia has increased over the last decade. During a routine health inspection on anise seeds collected from three localities in the province of Vojvodina (Mošorin, Veliki Radinci and Ostojićevo) during 2012 and 2013, it was found out that Fusarium spp. were a commonly observed fungi. The presence of Fusarium fungion the seed samples ranged from 3.75-13.75%. The aim of this study was to isolate and identify the strains of Fusarium species present on anise seed samples as it is necessary that commercially used anise seeds are completely free of Fusarium. Based on morphological, microscopic characteristics and a molecular identification by sequencing of TEF gene, the presence of the following species was confirmed on the anise seeds: F. tricinctum, F. proliferatum, F. equiseti, F. oxysporum, F. spor...
The isolation of bacteria was carried out from samples of straw and chicken manure, compost at va... more The isolation of bacteria was carried out from samples of straw and chicken manure, compost at various stages of the composting process and casing soil used for growing button mushrooms. A preliminary screening of 108 bacterial isolates for antagonistic activity against Trichoderma aggressivum f. europaeum showed that 23 tested isolates inhibited mycelial growth of the pathogenic fungus. Further screening with four indicator isolates of fungi revealed that all 23 bacterial isolates inhibited the growth of T. aggressivum f. europaeum, T. harzianum and T. koningii, while only 13 isolates inhibited the growth of T. atroviride. T. aggressivum f. europaeum proved to be the most sensitive, with many bacterial isolates generating a high percentage of growth inhibition. Only two bacterial isolates (B-129 and B-268) were successful in inhibiting the growth of all 4 tested pathogens. All 23 bacterial isolates were characterized as Gram-positive and catalase-positive and were subjected to mole...
The main aims of this study were to determine the overwintering form and the primary inoculum ofE... more The main aims of this study were to determine the overwintering form and the primary inoculum ofErysiphe necator,the causal agent of grapevine powdery mildew in southern Syria. Eleven vineyards located at five different geographical sites were visited every week from March to November in 2014 and 2015. The results of field and histopathological studies showed thatE. necatorsurvived as mycelium in dormant grapevine buds during the winter season. The first flag shoots were observed shortly after bud break in spring. The number of flag shoots varied greatly according to vineyards, cultivars and years, being present on 27.4 to 61.9% of the grapevines in 2014, and on 5.2 to 40% of the grapevines in 2015. The percentage of flag shoots on the same grapevine also varied according to the year, cultivar and location. It was between 4.3 to 9.4% in 2014, and 2.1 to 3.6% in 2015. The disease was observed only on Balady and Black cultivars. Conidia were released from the second week of May to ear...
Fifteen isolates of fungal endophytes of grasses were studied for their ability to metabolize dif... more Fifteen isolates of fungal endophytes of grasses were studied for their ability to metabolize different sources of carbon and nitrogen. These endophytes had been isolated from 12 different species of Poaceae and included Clavicipitaceae with or without a teleomorph (genera Epichloë and Neotyphodium, respectively) and species belonging to the genus Acremonium sensu stricto (Acremonium chilense-like). Pectin and cellulose as carbon sources and tryptophan and methionine as nitrogen sources appeared to support poorly the growth of most isolates. Hexoses, disaccharides, complex nitrogen sources, asparagine, and glutamine supported growth of all isolates. The isolates of genus Neotyphodium were characterized by limited growth whatever the substrate, the inhibition of their growth by high concentrations of glucose and fructose, and their inability to assimilate pentoses (xylose, arabinose) and nitrates. The isolates of genus Epichloë showed better growth than those of the previous group an...
Rhizoctonia stem canker and black scurf are among the most important diseases associated with pot... more Rhizoctonia stem canker and black scurf are among the most important diseases associated with potato (Solanum tuberosum L.) cultivation worldwide. Pathogenicity test of 19 isolates of Rhizoctonia solani Kühn obtained from four governorates in Syria revealed that isolates varied in their ability to cause disease with the isolate Rh15 being the most virulent in the development of the disease on potato plant under artificial infection. The relative susceptibility of seven commercial and local potato cultivars against R. solani was tested. The evaluation was based on black scurf severity and the negative impact of the disease on plant growth and expected effect on yield. The tested cultivars showed variable degrees of black scurf severity and consequent plant growth, but no completely immune cultivars were observed. Based on disease index (DI), potato varieties 'Agria', 'Ultra' and 'Labella' were highly susceptible to the disease; 'Spunta' was moderately resistant whereas 'Everest' was the most tolerant. Infection of the most susceptible cultivar "Afamia" resulted in the death of a large number of seedlings, large and deep canker on stems, with no formation of new tubers. Although 'Synergy' was moderately susceptible, and the black scurf incidence was higher than that of 'Everest' and 'Spunta', the loss of tubers weight was not significant compared to the previous two cultivars. The results suggested that use of tolerant and moderately resistant cultivars in Syria may help in reducing the development of black scurf on potatoes.
Archives of Phytopathology and Plant Protection, Oct 26, 2021
Abstract Crown and root rot of wheat is considered as one of the most damaging diseases, resultin... more Abstract Crown and root rot of wheat is considered as one of the most damaging diseases, resulting in significant yield losses in different regions worldwide. The aim of this study was to isolate and identify Fusarium species associated with crown rot of wheat in Syrian coastal areas. Ten Fusarium isolates were recovered from crowns and roots of durum wheat plants (var. Cham5), showing typical symptoms, collected from five different sites in coastal Tartous province. Based on morphological characteristics, 7 isolates were identified as F. incarnatum (syn. F. semitectum), and 3 isolates were F. solani. The sequencing of a partial TEF1-α gene of two representative isolates of these two species confirmed the morphological identification. Phylogenetic tree of partial TEF1-α gene showed a clear separation between the two species and high genetic similarity of Syrian and reference isolates. Up to our knowledge, this is the first report of F. incarnatum and F. solani infecting the roots and crowns of wheat in Syria.
Hamzeh, S., W. Naffaa and M.F. Azmeh. 2022. Occurrence of the Hyperparasite Ampelomyces quisquali... more Hamzeh, S., W. Naffaa and M.F. Azmeh. 2022. Occurrence of the Hyperparasite Ampelomyces quisqualis on Golovinomyces neosalviae (Erysiphaceae), Causal Agent of Powdery Mildew on Common Sage (Salvia officinalis). Arab Journal of Plant Protection, 40(2): 158-163. https://doi.org/10.22268/AJPP-040.2.158163 Ampelomyces quisqualis, the oldest mycoparasite of powdery mildew (PM), has been widely studied due to its potential in biocontrol. Many strains of this hyperparasite have been experimented worldwide and some of them were successfully applied for biocontrol, but others have been less efficient. No previous identification of Ampelomyces strains has been done in Syria, but some isolates were morphologically identified in the coastal region. There was no indication of Ampelomyces occurrence in any other location in Syria. During this three years survey (2019–2021), 73 plant samples were collected from five governorates, including coastal and southern regions in Syria. Ampelomyces pycnidi...
Powdery mildew caused by Erysiphe necator, is one of the most economically damaging diseases of g... more Powdery mildew caused by Erysiphe necator, is one of the most economically damaging diseases of grapevine throughout the world. This study aimed to identify the mating types of this pathogen in Syria using molecular markers. Three DNA extraction methods: Promega Kit, phenol chloroform isoamyl alcohol (PCI) and SDS were compared. The amount and quality of DNAs obtained by the SDS method were suitable for PCR amplification and other molecular assays. PCR amplification using specific primers (Uncin 144 and Uncin 511) was performed and the expected amplicon of 300-400 bp was obtained from 29 isolates of E. necator collected from different geographical locations and from different grapevine cultivars. Results obtained showed that E. necator may cause atypical symptoms similar to those of downy mildew, in some grapevine cultivars according to the environmental conditions and training system used. Isolates of E. necator were classified into four groups according to geographical locations a...
Abou Al-Fadil T., Naffaa W., Abou Fakher T., Muzher B. and Amer H. 2010. Apple Stem Canker Diseas... more Abou Al-Fadil T., Naffaa W., Abou Fakher T., Muzher B. and Amer H. 2010. Apple Stem Canker Disease in Sweida: the Causal Fungus and the Susceptibility of Some Apple Varieties to the Disease. Arab Journal of Plant Protection. 28(1), 16-19. Efforts to identify the causal organism of apple stem canker were carried out. Samples were taken from 25 apple trees showing symptoms of stem canker at five different geographical locations of Daher Al jabal area in Sweida to isolate and identify the causal organism. Results showed that more than 90% of the isolates were Alternaria alternate (Fries) Keissler. This pathogen was able to induce canker symptoms on stems of 12 apple varieties under artificial inoculation conditions. Isolates from different geographical sites differed in their pathogenicity. Apple varieties tested showed also significant differences in their susceptibility to the disease. Wealthy double red and Starking delicious varieties were the least susceptible, while Golden lody was the most susceptible to Alternaria canker disease.
Crown and collar rot of apple trees is a destructive and widespread disease in most areas of the ... more Crown and collar rot of apple trees is a destructive and widespread disease in most areas of the world. Surveys have been done to describe disease symptoms, estimate the disease incidence, and identify the pathogens associated with this disease in southern Syria. Disease incidence was 0.08 – 10 % in most studied sites, only in Alroom location it was up to 14.7 % in 2014 and 17.8 % in 2015, with average of 11.8 %. Symptoms included small pale green leaves, sparse foliage, and a reddish-brown discoloration of inner bark of the infected area at the base of infected tree. The isolated fungi belonged to genera and form genera Phytophthora, Rosellinia, Rhizoctonia, Phialophora, Acremonium, Pestalotiopsis, Cylindrocarpon and Verticillium. Phytophthora was isolated from all infected trees, and was the most frequent pathogen (53.7 % of total isolates). Phytophthora isolates recovered from crown cankers of apple were identified as P. cactorum (91.5 %) and P. cambivora (8.5 %). The results of ...
Anise (Pimpinella anisum L.) is an important medicinal spice plant that belongs to the family Api... more Anise (Pimpinella anisum L.) is an important medicinal spice plant that belongs to the family Apiaceae. Anise seeds are rich in essential oils and this is a reason why anise production in Serbia has increased over the last decade. During a routine health inspection on anise seeds collected from three localities in the province of Vojvodina (Mošorin, Veliki Radinci and Ostojićevo) during 2012 and 2013, it was found out that Fusarium spp. were a commonly observed fungi. The presence of Fusarium fungion the seed samples ranged from 3.75-13.75%. The aim of this study was to isolate and identify the strains of Fusarium species present on anise seed samples as it is necessary that commercially used anise seeds are completely free of Fusarium. Based on morphological, microscopic characteristics and a molecular identification by sequencing of TEF gene, the presence of the following species was confirmed on the anise seeds: F. tricinctum, F. proliferatum, F. equiseti, F. oxysporum, F. spor...
The isolation of bacteria was carried out from samples of straw and chicken manure, compost at va... more The isolation of bacteria was carried out from samples of straw and chicken manure, compost at various stages of the composting process and casing soil used for growing button mushrooms. A preliminary screening of 108 bacterial isolates for antagonistic activity against Trichoderma aggressivum f. europaeum showed that 23 tested isolates inhibited mycelial growth of the pathogenic fungus. Further screening with four indicator isolates of fungi revealed that all 23 bacterial isolates inhibited the growth of T. aggressivum f. europaeum, T. harzianum and T. koningii, while only 13 isolates inhibited the growth of T. atroviride. T. aggressivum f. europaeum proved to be the most sensitive, with many bacterial isolates generating a high percentage of growth inhibition. Only two bacterial isolates (B-129 and B-268) were successful in inhibiting the growth of all 4 tested pathogens. All 23 bacterial isolates were characterized as Gram-positive and catalase-positive and were subjected to mole...
The main aims of this study were to determine the overwintering form and the primary inoculum ofE... more The main aims of this study were to determine the overwintering form and the primary inoculum ofErysiphe necator,the causal agent of grapevine powdery mildew in southern Syria. Eleven vineyards located at five different geographical sites were visited every week from March to November in 2014 and 2015. The results of field and histopathological studies showed thatE. necatorsurvived as mycelium in dormant grapevine buds during the winter season. The first flag shoots were observed shortly after bud break in spring. The number of flag shoots varied greatly according to vineyards, cultivars and years, being present on 27.4 to 61.9% of the grapevines in 2014, and on 5.2 to 40% of the grapevines in 2015. The percentage of flag shoots on the same grapevine also varied according to the year, cultivar and location. It was between 4.3 to 9.4% in 2014, and 2.1 to 3.6% in 2015. The disease was observed only on Balady and Black cultivars. Conidia were released from the second week of May to ear...
Fifteen isolates of fungal endophytes of grasses were studied for their ability to metabolize dif... more Fifteen isolates of fungal endophytes of grasses were studied for their ability to metabolize different sources of carbon and nitrogen. These endophytes had been isolated from 12 different species of Poaceae and included Clavicipitaceae with or without a teleomorph (genera Epichloë and Neotyphodium, respectively) and species belonging to the genus Acremonium sensu stricto (Acremonium chilense-like). Pectin and cellulose as carbon sources and tryptophan and methionine as nitrogen sources appeared to support poorly the growth of most isolates. Hexoses, disaccharides, complex nitrogen sources, asparagine, and glutamine supported growth of all isolates. The isolates of genus Neotyphodium were characterized by limited growth whatever the substrate, the inhibition of their growth by high concentrations of glucose and fructose, and their inability to assimilate pentoses (xylose, arabinose) and nitrates. The isolates of genus Epichloë showed better growth than those of the previous group an...
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