Pub Date : 2020-12-31DOI: 10.33687/phytopath.009.03.3450
Hafiz M. Saqib, S. Chohan, M. Abid
Sunflower is an important oil seed crop of Pakistan, comprising 20% proteins and 38-45% oil contents. Alternaria leaf blight (ALB) caused by Alternaria alternata, is one of the devastating diseases of sunflower. Six different fungicides viz., difenoconazole, hexaconazole, azoxystrobin, dimethomorph + mancozeb, myclobutanil and Sulphur were tested at different concentrations (10, 20, 30 ppm) in laboratory and in greenhouse. Fungicides performed best in the laboratory were also investigated in greenhouse against Alternaria leaf blight of sunflower. In in vitro study, Hexaconazole showed 100 % growth inhibition of A. alternata at 30 ppm followed by 70% at 20 ppm and 62% at 10 ppm. Difenoconazole proved as the 2nd best fungicide with 77% fungal inhibition at 30 ppm, 75.8% at 20 ppm and 71% at 10 ppm. Azoxystrobin was the least effective fungicide with 24%, 28%, 34% fungal inhibition at 10, 20 and 30 ppm, respectively. Twelve cultivars of sunflower were screened against blight disease in pot experiment to check the fungicides at different level of susceptibility in greenhouse. Screening result showed that FH 702 was the highest susceptible variety with mean value 7.6. Greenhouse study of disease inhibition effect of fungicides also showed that hexaconazole fungicide produced the best results against A. alternata with 42% disease reduction in FH 702 cultivar and 25 % in FH 696 cultivar as compared to control (83%). The results showed that no fungicide provided full disease inhibition, so, further investigation is needed to find the new chemistry against blight disease of sunflower crop
{"title":"Chemical Management of Alternaria Leaf Blight of Sunflower","authors":"Hafiz M. Saqib, S. Chohan, M. Abid","doi":"10.33687/phytopath.009.03.3450","DOIUrl":"https://doi.org/10.33687/phytopath.009.03.3450","url":null,"abstract":"Sunflower is an important oil seed crop of Pakistan, comprising 20% proteins and 38-45% oil contents. Alternaria leaf blight (ALB) caused by Alternaria alternata, is one of the devastating diseases of sunflower. Six different fungicides viz., difenoconazole, hexaconazole, azoxystrobin, dimethomorph + mancozeb, myclobutanil and Sulphur were tested at different concentrations (10, 20, 30 ppm) in laboratory and in greenhouse. Fungicides performed best in the laboratory were also investigated in greenhouse against Alternaria leaf blight of sunflower. In in vitro study, Hexaconazole showed 100 % growth inhibition of A. alternata at 30 ppm followed by 70% at 20 ppm and 62% at 10 ppm. Difenoconazole proved as the 2nd best fungicide with 77% fungal inhibition at 30 ppm, 75.8% at 20 ppm and 71% at 10 ppm. Azoxystrobin was the least effective fungicide with 24%, 28%, 34% fungal inhibition at 10, 20 and 30 ppm, respectively. Twelve cultivars of sunflower were screened against blight disease in pot experiment to check the fungicides at different level of susceptibility in greenhouse. Screening result showed that FH 702 was the highest susceptible variety with mean value 7.6. Greenhouse study of disease inhibition effect of fungicides also showed that hexaconazole fungicide produced the best results against A. alternata with 42% disease reduction in FH 702 cultivar and 25 % in FH 696 cultivar as compared to control (83%). The results showed that no fungicide provided full disease inhibition, so, further investigation is needed to find the new chemistry against blight disease of sunflower crop","PeriodicalId":36106,"journal":{"name":"International Journal of Phytopathology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81286309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-28DOI: 10.33687/phytopath.009.03.3417
H. Arshad, J. A. Khan, K. Saleem, S. S. Alam, S. T. Sahi
Bacterial leaf blight (BLB) is one of the most damaging diseases of rice in Asia and annually incurring significant yield loss to rice production in Pakistan. Management of disease required the information of BLB incidence and severity in basmati and non-basmati rice areas. The current study presented the observation of BLB disease incidence and severity in 19 major rice growing districts of Punjab. In this study, 9 Basmati growing and 10 non-basmati rice growing districts were surveyed from September to October in 2009, 2010, 2012, and 2013. Rice fields near to roadside, research stations and adjoining farmer fields were preferred for the survey. Each halt was after 10 km on the route depending upon the crop intensity. The general appearance of the field was observed for the absence or presence of BLB disease symptoms. The incidence of BLB was recorded as a percentage of plants infected in a field on a visual basis. For each field, 4 plants were observed at 5 points/hill along the diagonal transect for disease symptoms. The data of severity was recorded as the percentage of leaf area infected out of the total leaf area. Among the districts with basmati rice, the mean incidence of BLB was maximum in Gujranwala, Sheikhupura and Hafizabad followed by Mandi Bahauddin and Gujrat. A similar pattern of disease severity was observed in the basmati rice belt with maximum BLB mean severity in Gujranwala, Sheikhupura and Hafizabad having most of the field with a severity scale of 9. Overall, the disease trend showed that both the incidence and the severity were higher in 2010, 2012 and 2013 in the basmati rice belt. The ten districts, comprising of mostly non-basmati rice varieties showed relatively less BLB incidence and severity compared to basmati rice districts. The maximum mean incidence of 20-25% was observed in Faisalabad, Chiniot and Sahiwal in at least one year of the rice season. None of the field with BLB disease symptoms was observed in districts Okara, Khanewal and Bahawalpur during the 2012 and 2013 rice season. Maximum disease severity of mean value 3 was observed in Sahiwal during 2009 while the rest of the districts showed less than 2 mean severity during all rice growing season. Overall, in non-basmati rice districts, no specific trend of disease incidence and severity was apparent, however, the disease was present in very low magnitude or absent during the surveyed years. The information from this study is helpful in the selection of variety for basmati and non-basmati districts of Punjab and the adoption of appropriate disease management strategies.
{"title":"Bacterial Leaf Blight (BLB) Disease Incidence and Severity in Basmati and Non-Basmati Rice Growing Areas of Punjab, Pakistan","authors":"H. Arshad, J. A. Khan, K. Saleem, S. S. Alam, S. T. Sahi","doi":"10.33687/phytopath.009.03.3417","DOIUrl":"https://doi.org/10.33687/phytopath.009.03.3417","url":null,"abstract":"Bacterial leaf blight (BLB) is one of the most damaging diseases of rice in Asia and annually incurring significant yield loss to rice production in Pakistan. Management of disease required the information of BLB incidence and severity in basmati and non-basmati rice areas. The current study presented the observation of BLB disease incidence and severity in 19 major rice growing districts of Punjab. In this study, 9 Basmati growing and 10 non-basmati rice growing districts were surveyed from September to October in 2009, 2010, 2012, and 2013. Rice fields near to roadside, research stations and adjoining farmer fields were preferred for the survey. Each halt was after 10 km on the route depending upon the crop intensity. The general appearance of the field was observed for the absence or presence of BLB disease symptoms. The incidence of BLB was recorded as a percentage of plants infected in a field on a visual basis. For each field, 4 plants were observed at 5 points/hill along the diagonal transect for disease symptoms. The data of severity was recorded as the percentage of leaf area infected out of the total leaf area. Among the districts with basmati rice, the mean incidence of BLB was maximum in Gujranwala, Sheikhupura and Hafizabad followed by Mandi Bahauddin and Gujrat. A similar pattern of disease severity was observed in the basmati rice belt with maximum BLB mean severity in Gujranwala, Sheikhupura and Hafizabad having most of the field with a severity scale of 9. Overall, the disease trend showed that both the incidence and the severity were higher in 2010, 2012 and 2013 in the basmati rice belt. The ten districts, comprising of mostly non-basmati rice varieties showed relatively less BLB incidence and severity compared to basmati rice districts. The maximum mean incidence of 20-25% was observed in Faisalabad, Chiniot and Sahiwal in at least one year of the rice season. None of the field with BLB disease symptoms was observed in districts Okara, Khanewal and Bahawalpur during the 2012 and 2013 rice season. Maximum disease severity of mean value 3 was observed in Sahiwal during 2009 while the rest of the districts showed less than 2 mean severity during all rice growing season. Overall, in non-basmati rice districts, no specific trend of disease incidence and severity was apparent, however, the disease was present in very low magnitude or absent during the surveyed years. The information from this study is helpful in the selection of variety for basmati and non-basmati districts of Punjab and the adoption of appropriate disease management strategies.","PeriodicalId":36106,"journal":{"name":"International Journal of Phytopathology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83023525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-07DOI: 10.33687/phytopath.008.03.2996
Yanmin Zhu, M. Saltzgiver
Plant resistance responses to pathogen infection involve massive transcriptional reprograming and widespread redirection of cellular pathways to adjust the plant from growth to defense. Transcription factors (TFs) function at the major regulating points of gene expression, and specific TFs are known to play crucial roles in plant defense activation. Molecular defense activation in apple root from infection by oomycete necrotrophic pathogen Pythium ultimum, a primary component in a pathogen complex inciting apple replant disease, has not been investigated in detail. Base on previous transcriptome analyses, members of apple WRKY gene family have been identified as the primary candidates in regulating defense response in apple root. Among them, MdWRKY33, an orthologue of AtWRKY33 in apple genome, demonstrated as a highly-expressed WRKY with genotype-specific induction patterns during P. ultimum infection. The sequence features of MdWRKY33 and its tissue-specific expression, as well as its responses to abiotic and pharmacological treatments, added to the evidence for its functional roles in defense activation in apple root. In response to P. ultimum infection, MdWRKY33 was consistently upregulated in all eight tested apple rootstock genotypes at all timepoints. Between genotypes, the stronger induction patterns at the earlier stage of infection in resistant genotypes suggest its essential roles of contributing to apple root resistance, although plant resistance to necrotrophic pathogens is polygenetic quantitative resistance in nature. Transgenic manipulation of this gene is underway to provide more definitive functional identity in contributing to apple root resistance to P. ultimum infection
{"title":"Transcriptional Profiles of Mdwrky33 in Apple Root in Response to Infection by Pythium Ultimum, Abiotic Stresses and Chemical Treatments","authors":"Yanmin Zhu, M. Saltzgiver","doi":"10.33687/phytopath.008.03.2996","DOIUrl":"https://doi.org/10.33687/phytopath.008.03.2996","url":null,"abstract":"Plant resistance responses to pathogen infection involve massive transcriptional reprograming and widespread redirection of cellular pathways to adjust the plant from growth to defense. Transcription factors (TFs) function at the major regulating points of gene expression, and specific TFs are known to play crucial roles in plant defense activation. Molecular defense activation in apple root from infection by oomycete necrotrophic pathogen Pythium ultimum, a primary component in a pathogen complex inciting apple replant disease, has not been investigated in detail. Base on previous transcriptome analyses, members of apple WRKY gene family have been identified as the primary candidates in regulating defense response in apple root. Among them, MdWRKY33, an orthologue of AtWRKY33 in apple genome, demonstrated as a highly-expressed WRKY with genotype-specific induction patterns during P. ultimum infection. The sequence features of MdWRKY33 and its tissue-specific expression, as well as its responses to abiotic and pharmacological treatments, added to the evidence for its functional roles in defense activation in apple root. In response to P. ultimum infection, MdWRKY33 was consistently upregulated in all eight tested apple rootstock genotypes at all timepoints. Between genotypes, the stronger induction patterns at the earlier stage of infection in resistant genotypes suggest its essential roles of contributing to apple root resistance, although plant resistance to necrotrophic pathogens is polygenetic quantitative resistance in nature. Transgenic manipulation of this gene is underway to provide more definitive functional identity in contributing to apple root resistance to P. ultimum infection","PeriodicalId":36106,"journal":{"name":"International Journal of Phytopathology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80380175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-30DOI: 10.33687/phytopath.008.03.2945
M. A. Gaber, E. Wagih, M. Shehata, Magda M. Fahmy, H. Wahab
Botrytis cinerea is a necrotrophic plant pathogen that causes plenty of crop losses in Egypt and worldwide. Fifteen isolates of B. cinerea were collected from cabbage, pepper and lettuce grown in different locations in Egypt and subjected to investigation. Diversity in phenotypic, pathological and molecular characteristics was detected among isolates, leading to categorising them into four different groups. Molecular variation was demonstrated in all isolates by transposable elements (TEs) analyses. Four TE types, based on the presence or absence of two transposable elements, boty and flipper, were recognised among B. cinerea isolates in which transposa type (having both TE, boty + flipper) was predominant (40%), while only boty and only flipper types appeared with distribution values of 26.7 and 20%, respectively and vacuma type (Lacking both TEs) showed the lowest distribution value (13.3%). Furthermore, vacuma population demonstrated the lowest potential comparing to others. A correlation was found between TE type and virulence level of isolate, but no impact of TE type was observed on phenotypic characteristics of B. cinerea. The present study revealed a correlation between the TE type and the isolate virulence, but no correlation was observed between phenotypic characteristic/sensitivity to fenhexamid and TE type
{"title":"Detection and Characterization of Botrytis cinerea Isolates from Vegetables in Egypt","authors":"M. A. Gaber, E. Wagih, M. Shehata, Magda M. Fahmy, H. Wahab","doi":"10.33687/phytopath.008.03.2945","DOIUrl":"https://doi.org/10.33687/phytopath.008.03.2945","url":null,"abstract":"Botrytis cinerea is a necrotrophic plant pathogen that causes plenty of crop losses in Egypt and worldwide. Fifteen isolates of B. cinerea were collected from cabbage, pepper and lettuce grown in different locations in Egypt and subjected to investigation. Diversity in phenotypic, pathological and molecular characteristics was detected among isolates, leading to categorising them into four different groups. Molecular variation was demonstrated in all isolates by transposable elements (TEs) analyses. Four TE types, based on the presence or absence of two transposable elements, boty and flipper, were recognised among B. cinerea isolates in which transposa type (having both TE, boty + flipper) was predominant (40%), while only boty and only flipper types appeared with distribution values of 26.7 and 20%, respectively and vacuma type (Lacking both TEs) showed the lowest distribution value (13.3%). Furthermore, vacuma population demonstrated the lowest potential comparing to others. A correlation was found between TE type and virulence level of isolate, but no impact of TE type was observed on phenotypic characteristics of B. cinerea. The present study revealed a correlation between the TE type and the isolate virulence, but no correlation was observed between phenotypic characteristic/sensitivity to fenhexamid and TE type","PeriodicalId":36106,"journal":{"name":"International Journal of Phytopathology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79326261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-30DOI: 10.33687/phytopath.008.02.2965
Aneliya Etropolska, F. Lefort
In recent years, ‘Ca. P. prunorum’, the agent of ESFY was reported from several apricot orchards of Canton of Wallis, the main apricot production region in Switzerland (Genini and Ramel, 2004). The psyllid vector Cacopsylla pruni was also found in several locations in the Lake Geneva area (Ackermann et al., 2006). The presence of the disease and of its proven vector C. pruni at the eastern part of the Lake Geneva area, as well as the existing risk of dissemination of ESFY to other stone fruit orchards along the Lake Geneva are the reasons for which ESFY needs to be studied further. ESFY and its possible dissemination through C. pruni on the territory of Canton of Geneva, bordering France, has never been yet studied. In 2016, visual observations were conducted in several stone fruit orchards near Geneva. Plant material was obtained from peach trees, displaying some of the typical symptoms such premature leaf colouration, leaf-roll, tree decline (Sabaté et al., 2015), in the autumn, when the concentration of the phytoplasma in the upper parts of the trees is the highest. Phloem was prepared from branches and was extracted with a CTAB-based adapted protocol (Lefort and Douglas, 1999). PCR amplification of phytoplasma DNA was achieved with the universal primers: fP1/rP7 (Deng and Hiruki, 1991; Schneider et al., 1995). All positive samples were tested with the ESFY-specific non-ribosomal primers ECA1/ECA2 (Jarausch et al., 1998). Typical symptoms of ESFY, like premature leaf colouration, leaf yellowing with reddish edges, leaf-roll, severe chlorosis, die-back of top branches and partial or, complete decline of the trees (Figure 1) were found in a peach orchard (GPS coordinates: 46°15'17.4"N 6°12'40.7"E) located in the area of Collonge-Bellerive, close to Geneva city. Ten trees were sampled in this orchard. The presence of ‘Ca. P. prunorum’ was confirmed in two of them (Figure 2 and Figure 3). At the beginning of spring 2017, the monitoring of the ESFY symptoms in the infested orchard was resumed. Early bud break was found on the two infected trees and the infection was confirmed again by PCR (Figure 4 and Figure 5). The same symptoms were observed in many trees of this orchard, which correlated with the previous autumn observations. Trapping confirmed the presence of the insect vector Cacopsylla pruni (Bodnár et al., 2018) in the infected area. In order to understand more about the origin and the diversity of ESFY phytoplasma in this area, additional plant and insect samples will be analyzed. The correlation between symptoms and infected plants will be studied further. We report here for the first time on the occurrence of ‘Candidatus Phytoplasma prunorum’ (‘Ca. P. prunorum’) the agent of ESFY on the territory of Canton of Geneva.
近年来，“Ca。瑞士主要杏树产区瓦利斯州(Canton of Wallis)的几个杏园报道了ESFY的代理人prunorum (Genini and Ramel, 2004)。在日内瓦湖地区的几个地点也发现了木虱病媒仙人掌(Cacopsylla pruni) (Ackermann et al.， 2006)。在日内瓦湖地区东部地区存在这种疾病及其已证实的病媒普鲁尼梭菌，以及在日内瓦湖沿岸的其他核果果园存在ESFY传播的风险，这是需要进一步研究ESFY的原因。ESFY及其可能通过C. pruni在与法国接壤的日内瓦州境内传播的研究从未进行过。2016年，在日内瓦附近的几个核桃园进行了目视观察。从桃树获得的植物材料，在树木上部植物原体浓度最高的秋季，表现出一些典型的症状，如叶片过早变色、叶卷、树木下降(sabat et al.， 2015)。从树枝中提取韧皮部，并采用基于ctab的改进方案提取韧皮部(Lefort和Douglas, 1999)。采用通用引物fP1/rP7 (Deng and Hiruki, 1991;Schneider et al.， 1995)。所有阳性样本均用esfy特异性非核糖体引物ECA1/ECA2进行检测(Jarausch et al.， 1998)。ESFY的典型症状，如叶子过早变色、叶子泛黄且边缘偏红、叶卷、严重褪绿、顶部树枝枯死和树木部分或完全衰败(图1)，在靠近日内瓦市的Collonge-Bellerive地区的一个桃园(GPS坐标:46°15'17.4"N 6°12'40.7"E)中发现。在这个果园里采集了十棵树的样本。Ca的存在。其中2个果园确认为prunorum '(图2和图3)。2017年春初，恢复了对侵染果园ESFY症状的监测。两棵感染的树都出现了早芽，通过PCR再次证实了感染(图4和图5)。该果园的许多树都出现了相同的症状，这与之前秋季的观察结果相关。诱捕证实在感染区域存在昆虫媒介卡波西拉(Bodnár et al.， 2018)。为了进一步了解该地区ESFY植物原体的来源和多样性，将对更多的植物和昆虫样本进行分析。病征与病株之间的关系有待进一步研究。我们在此首次报道了' Candidatus Phytoplasma prunorum ' (' Ca。P. prunorum)是ESFY在日内瓦州境内的代理人。
{"title":"First report of Candidatus Phytoplasma prunorum, the European stone fruit yellows phytoplasma on peach trees on the territory of Canton of Geneva, Switzerland","authors":"Aneliya Etropolska, F. Lefort","doi":"10.33687/phytopath.008.02.2965","DOIUrl":"https://doi.org/10.33687/phytopath.008.02.2965","url":null,"abstract":"In recent years, ‘Ca. P. prunorum’, the agent of ESFY was reported from several apricot orchards of Canton of Wallis, the main apricot production region in Switzerland (Genini and Ramel, 2004). The psyllid vector Cacopsylla pruni was also found in several locations in the Lake Geneva area (Ackermann et al., 2006). The presence of the disease and of its proven vector C. pruni at the eastern part of the Lake Geneva area, as well as the existing risk of dissemination of ESFY to other stone fruit orchards along the Lake Geneva are the reasons for which ESFY needs to be studied further. ESFY and its possible dissemination through C. pruni on the territory of Canton of Geneva, bordering France, has never been yet studied. In 2016, visual observations were conducted in several stone fruit orchards near Geneva. Plant material was obtained from peach trees, displaying some of the typical symptoms such premature leaf colouration, leaf-roll, tree decline (Sabaté et al., 2015), in the autumn, when the concentration of the phytoplasma in the upper parts of the trees is the highest. Phloem was prepared from branches and was extracted with a CTAB-based adapted protocol (Lefort and Douglas, 1999). PCR amplification of phytoplasma DNA was achieved with the universal primers: fP1/rP7 (Deng and Hiruki, 1991; Schneider et al., 1995). All positive samples were tested with the ESFY-specific non-ribosomal primers ECA1/ECA2 (Jarausch et al., 1998). Typical symptoms of ESFY, like premature leaf colouration, leaf yellowing with reddish edges, leaf-roll, severe chlorosis, die-back of top branches and partial or, complete decline of the trees (Figure 1) were found in a peach orchard (GPS coordinates: 46°15'17.4\"N 6°12'40.7\"E) located in the area of Collonge-Bellerive, close to Geneva city. Ten trees were sampled in this orchard. The presence of ‘Ca. P. prunorum’ was confirmed in two of them (Figure 2 and Figure 3). At the beginning of spring 2017, the monitoring of the ESFY symptoms in the infested orchard was resumed. Early bud break was found on the two infected trees and the infection was confirmed again by PCR (Figure 4 and Figure 5). The same symptoms were observed in many trees of this orchard, which correlated with the previous autumn observations. Trapping confirmed the presence of the insect vector Cacopsylla pruni (Bodnár et al., 2018) in the infected area. In order to understand more about the origin and the diversity of ESFY phytoplasma in this area, additional plant and insect samples will be analyzed. The correlation between symptoms and infected plants will be studied further. We report here for the first time on the occurrence of ‘Candidatus Phytoplasma prunorum’ (‘Ca. P. prunorum’) the agent of ESFY on the territory of Canton of Geneva.","PeriodicalId":36106,"journal":{"name":"International Journal of Phytopathology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85537246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-30DOI: 10.33687/phytopath.008.02.2967
Hadeel M. M. Khalil Bagy, K. Abo-Elyousr
Bacterial spot disease caused by Xanthomonas axonopodis pv. vesicatoria is considered one of the major diseases of tomato crop worldwide. The objective of this paper was to study the effect of certain essential oils (EOs), lemongrass, oleum and thyme, on X. axonopodis pv. vesicatoria (PHYX14) for controlling bacterial spot disease in tomato plants. The tested three essential oils (EOs) showed antibacterial activity in vitro test at 1:10 concentration against the PHYX14.Thyme oil exhibited the highest inhibition against PHYX14 followed by lemongrass and finally oleum. Under greenhouse conditions, the effect of EOs on the bacterial spot of tomato was evaluated on tomato seedlings. Thyme oil exhibited the highest reducing of tomato bacterial spot followed oleum and then lemongrass. Results indicated that the application of the tested (EOs) to tomato plants two days after the infection caused the highest reduction of disease severity. While the application of oleum oil exhibited the highest induction of the oxidative enzymes, peroxidase (PO) and polyphenol enzyme (PPO). Also increased total phenolic contents of tomato leaves followed lemongrass and then thyme oil as compared by control. The application of EOs two days before the infection caused the highest induction of PO, PPO enzymes and total phenolic contents in tomato leaves than two days after the inoculation.
{"title":"Antibacterial activity of some essential oils on bacterial spot disease of tomato plant caused by Xanthomonas axonopodis pv. vesicatoria","authors":"Hadeel M. M. Khalil Bagy, K. Abo-Elyousr","doi":"10.33687/phytopath.008.02.2967","DOIUrl":"https://doi.org/10.33687/phytopath.008.02.2967","url":null,"abstract":"Bacterial spot disease caused by Xanthomonas axonopodis pv. vesicatoria is considered one of the major diseases of tomato crop worldwide. The objective of this paper was to study the effect of certain essential oils (EOs), lemongrass, oleum and thyme, on X. axonopodis pv. vesicatoria (PHYX14) for controlling bacterial spot disease in tomato plants. The tested three essential oils (EOs) showed antibacterial activity in vitro test at 1:10 concentration against the PHYX14.Thyme oil exhibited the highest inhibition against PHYX14 followed by lemongrass and finally oleum. Under greenhouse conditions, the effect of EOs on the bacterial spot of tomato was evaluated on tomato seedlings. Thyme oil exhibited the highest reducing of tomato bacterial spot followed oleum and then lemongrass. Results indicated that the application of the tested (EOs) to tomato plants two days after the infection caused the highest reduction of disease severity. While the application of oleum oil exhibited the highest induction of the oxidative enzymes, peroxidase (PO) and polyphenol enzyme (PPO). Also increased total phenolic contents of tomato leaves followed lemongrass and then thyme oil as compared by control. The application of EOs two days before the infection caused the highest induction of PO, PPO enzymes and total phenolic contents in tomato leaves than two days after the inoculation.","PeriodicalId":36106,"journal":{"name":"International Journal of Phytopathology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72637107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-30DOI: 10.33687/phytopath.008.02.2890
G. Downs, D. Upadhyay, S. Mandjiny, J. Frederick, L. Holmes
Entomopathogenic nematodes (in the genus Steinernema and Heterorhabditis) have been studied and successfully commercialized as biological control agents. These organisms are highly virulent and safe for the non-target environment, animals and humans. For at least 200 target species, the nematode-bacteria complex has the potential to become a mass-marketed agricultural biopesticide. However, before nematodes can be successfully integrated into the agricultural system as a regular-use, “go-to” biopesticide, it is necessary to develop economical manufacturing processes. There are several manufacturing platforms: in vitro solid fermentation; in vitro liquid fermentation; and in vivo production. This review presents an analysis of each approach and discusses the advantages and disadvantages relative to the cost of production, technical expertise required, and quality of the final product.
{"title":"Biological Control Technology Utilizing Heterorhabditis bacteriophora and Steinernema carpocapsae","authors":"G. Downs, D. Upadhyay, S. Mandjiny, J. Frederick, L. Holmes","doi":"10.33687/phytopath.008.02.2890","DOIUrl":"https://doi.org/10.33687/phytopath.008.02.2890","url":null,"abstract":"Entomopathogenic nematodes (in the genus Steinernema and Heterorhabditis) have been studied and successfully commercialized as biological control agents. These organisms are highly virulent and safe for the non-target environment, animals and humans. For at least 200 target species, the nematode-bacteria complex has the potential to become a mass-marketed agricultural biopesticide. However, before nematodes can be successfully integrated into the agricultural system as a regular-use, “go-to” biopesticide, it is necessary to develop economical manufacturing processes. There are several manufacturing platforms: in vitro solid fermentation; in vitro liquid fermentation; and in vivo production. This review presents an analysis of each approach and discusses the advantages and disadvantages relative to the cost of production, technical expertise required, and quality of the final product.","PeriodicalId":36106,"journal":{"name":"International Journal of Phytopathology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72815674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-30DOI: 10.33687/phytopath.008.02.2939
M. Nita, A. Atwal, Amanda Bly, Kara Lewallen
The growth and symptom development of two fungal species, Colletotrichum siamense, and C. fioriniae were examined using in vitro and in planta assays. In a plate assay, C. siamense grew fastest at 30 °C and at 25 °C, but C. fioriniae grew slower at 30 °C than at 25 °C. With apple inoculation assay, the mean lesion diameters at 30 °C were significantly larger (P ≤ 0.05) than that at 20 °C on a cultivar Ida Red for both fungal species. On the other hand, the mean lesion diameter on a cultivar Golden Delicious was significantly larger at 20 °C than at 30 °C for both fungal species. Therefore, the rate of lesion development was influenced not only by fungal species and incubation temperature but also by apple cultivar. In this study, cultivar ‘Ida red’ was found to be more susceptible to C. siamense under warm environmental condition. Although both species were able to grow at 10 °C in the plate assay, no disease symptoms were developed at 10 °C with the inoculation assay. Although the numbers of cultivar and fungal species are small, to our knowledge, this is the first report to describe potential interactive effect among Colletotrichum species, temperature, and apple cultivar on the rate of bitter rot symptom development.
{"title":"The growth rate of apple bitter rot lesion, caused by Colletotrichum spp., is affected by temperature, fungal species, and cultivar.","authors":"M. Nita, A. Atwal, Amanda Bly, Kara Lewallen","doi":"10.33687/phytopath.008.02.2939","DOIUrl":"https://doi.org/10.33687/phytopath.008.02.2939","url":null,"abstract":"The growth and symptom development of two fungal species, Colletotrichum siamense, and C. fioriniae were examined using in vitro and in planta assays. In a plate assay, C. siamense grew fastest at 30 °C and at 25 °C, but C. fioriniae grew slower at 30 °C than at 25 °C. With apple inoculation assay, the mean lesion diameters at 30 °C were significantly larger (P ≤ 0.05) than that at 20 °C on a cultivar Ida Red for both fungal species. On the other hand, the mean lesion diameter on a cultivar Golden Delicious was significantly larger at 20 °C than at 30 °C for both fungal species. Therefore, the rate of lesion development was influenced not only by fungal species and incubation temperature but also by apple cultivar. In this study, cultivar ‘Ida red’ was found to be more susceptible to C. siamense under warm environmental condition. Although both species were able to grow at 10 °C in the plate assay, no disease symptoms were developed at 10 °C with the inoculation assay. Although the numbers of cultivar and fungal species are small, to our knowledge, this is the first report to describe potential interactive effect among Colletotrichum species, temperature, and apple cultivar on the rate of bitter rot symptom development.","PeriodicalId":36106,"journal":{"name":"International Journal of Phytopathology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89307795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-30DOI: 10.33687/phytopath.008.02.2943
E. Wagih, H. Wahab, M. Shehata, Magda M. Fahmy, M. A. Gaber
Grey mold caused by Botrytis cinerea, is known to cause great losses in most vegetable and fruit crops. Fifty-one isolates of B. cinerea were collected from grape (BCG) and strawberry (BCS) grown in different Egyptian locations. Variation among isolates was demonstrated using fenhexamid resistance and genetic approaches. Isolates were classified into various pathogenic groups depending on their reactions towards lettuce leaves. Genetic variability was identified in all isolates using transposable elements (TEs) analysis which revealed either the presence or absence of boty and flipper transposons. Furthermore, TEs typing of B. cinerea isolates demonstrated four TE types, on the basis of TE distribution in B. cinerea populations, namely, transposa (having both boty and flipper), flipper (possessing only flipper), boty (having only boty), and vacuma (lacking both boty and flipper elements). Transposa type was predominant (43.1%) and both transposa and vacuma isolate types showed no specialization with respect to host plant or plant location, while flipper type revealed a geographical preference in (BCG) isolates. Pathogenicity was also correlated to TE type as isolates containing transposa type revealed some degree of correlation with virulence behaviour, suggesting that transposa populations have higher pathogenic potential as compared to vacuma ones. The sensitivity of sampled isolates was tested against fenhexamid as one of the most important botryticides. Sensitivity to fenhexamid was shown in all isolates from strawberry and grape, grown in different locations, with low EC50 values between 0.012-0.084 μg/ml. This finding provided a cue for effective usage of fenhexamid for grey mold management. The present work demonstrated a correlation between the distribution of TEs and some fungal features such as isolate source and virulence, but no correlation was found between morphological characteristics, TE type, and sensitivity to fenhexamid. Cluster analysis based on phylogenetic tree showed that the Egyptian isolates branched as a separate divergent group from the others retrieved from GenBank, reflecting the presence of sequence polymorphism between the current isolates of B. cinerea and those previously identified.
{"title":"Molecular and Pathological Variability Associated with Transposable Elements of Botrytis Cinerea Isolates Infecting Grape and Strawberry in Egypt","authors":"E. Wagih, H. Wahab, M. Shehata, Magda M. Fahmy, M. A. Gaber","doi":"10.33687/phytopath.008.02.2943","DOIUrl":"https://doi.org/10.33687/phytopath.008.02.2943","url":null,"abstract":"Grey mold caused by Botrytis cinerea, is known to cause great losses in most vegetable and fruit crops. Fifty-one isolates of B. cinerea were collected from grape (BCG) and strawberry (BCS) grown in different Egyptian locations. Variation among isolates was demonstrated using fenhexamid resistance and genetic approaches. Isolates were classified into various pathogenic groups depending on their reactions towards lettuce leaves. Genetic variability was identified in all isolates using transposable elements (TEs) analysis which revealed either the presence or absence of boty and flipper transposons. Furthermore, TEs typing of B. cinerea isolates demonstrated four TE types, on the basis of TE distribution in B. cinerea populations, namely, transposa (having both boty and flipper), flipper (possessing only flipper), boty (having only boty), and vacuma (lacking both boty and flipper elements). Transposa type was predominant (43.1%) and both transposa and vacuma isolate types showed no specialization with respect to host plant or plant location, while flipper type revealed a geographical preference in (BCG) isolates. Pathogenicity was also correlated to TE type as isolates containing transposa type revealed some degree of correlation with virulence behaviour, suggesting that transposa populations have higher pathogenic potential as compared to vacuma ones. The sensitivity of sampled isolates was tested against fenhexamid as one of the most important botryticides. Sensitivity to fenhexamid was shown in all isolates from strawberry and grape, grown in different locations, with low EC50 values between 0.012-0.084 μg/ml. This finding provided a cue for effective usage of fenhexamid for grey mold management. The present work demonstrated a correlation between the distribution of TEs and some fungal features such as isolate source and virulence, but no correlation was found between morphological characteristics, TE type, and sensitivity to fenhexamid. Cluster analysis based on phylogenetic tree showed that the Egyptian isolates branched as a separate divergent group from the others retrieved from GenBank, reflecting the presence of sequence polymorphism between the current isolates of B. cinerea and those previously identified.","PeriodicalId":36106,"journal":{"name":"International Journal of Phytopathology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87986844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-30DOI: 10.33687/PHYTOPATH.008.01.2899
M. Khalil, Abdulqawi A. A. Alqadasi
Currently, plant parasitic nematodes (PPN) especially root knot nematodes, Meloidogyne spp. have been found involved in the global losses of tomato crops. The most employed tactic for managing PPN in Africa is non-fumigant nematicides. Recently, in Egypt abamectin was recorded as a new tool to control PPN. Thus, two pot experiments were conducted to evaluate the potential of abamectin and certain non-fumigant nematicides namely; oxamyl and ethoprophos at two different formulations (granular and liquid) against southern root knot nematode (Meloidogyne incognita) on tomato plants under greenhouse conditions. Results revealed the granular formulations of ethoprophos and oxamyl, in addition to abamectin, showed the same significance (P≤0.05) in suppressing tomato soil population and root galls of M. incognita, during both experiments. However, liquid formulations of ethoprophos and oxamyl gave relatively less decreasing in soil population and root galls. On the other hand, all applied treatments improved plant growth criteria ranging from 36.92 to 126.44% in shoot dry weight and from 31.25 to 137.50% in root dry weight for both experiments.
{"title":"Potential of non-fumigant nematicides at different formulations against southern root-knot nematode (Meloidogyne incognita) on tomato plants","authors":"M. Khalil, Abdulqawi A. A. Alqadasi","doi":"10.33687/PHYTOPATH.008.01.2899","DOIUrl":"https://doi.org/10.33687/PHYTOPATH.008.01.2899","url":null,"abstract":"Currently, plant parasitic nematodes (PPN) especially root knot nematodes, Meloidogyne spp. have been found involved in the global losses of tomato crops. The most employed tactic for managing PPN in Africa is non-fumigant nematicides. Recently, in Egypt abamectin was recorded as a new tool to control PPN. Thus, two pot experiments were conducted to evaluate the potential of abamectin and certain non-fumigant nematicides namely; oxamyl and ethoprophos at two different formulations (granular and liquid) against southern root knot nematode (Meloidogyne incognita) on tomato plants under greenhouse conditions. Results revealed the granular formulations of ethoprophos and oxamyl, in addition to abamectin, showed the same significance (P≤0.05) in suppressing tomato soil population and root galls of M. incognita, during both experiments. However, liquid formulations of ethoprophos and oxamyl gave relatively less decreasing in soil population and root galls. On the other hand, all applied treatments improved plant growth criteria ranging from 36.92 to 126.44% in shoot dry weight and from 31.25 to 137.50% in root dry weight for both experiments.","PeriodicalId":36106,"journal":{"name":"International Journal of Phytopathology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78423929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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