Y. O. Masheti, J. W. Muthomi, W. M. Muiru, E. E. Arunga, P. Gepts
This research addresses the presence of Elsinoë phaseoli in Kenya, where information on the biology of this pathogen remains scarce. Employing a multifaceted approach, the study demonstrates the steps taken to isolate, identify, and characterize E. phaseoli as the pathogen responsible for scab on common bean. Field observations confirmed scab symptoms, particularly the prominent pod lesions. Elsinoë phaseoli was isolated from common bean using a targeted streaking method on older acervulus-bearing lesions. Morphological examinations revealed a notable diversity within E. phaseoli colonies, consistent with the characteristics of the genus. Molecular identification through ITS-rDNA sequencing confirmed isolate AscoSK1 obtained in this study as belonging to E. phaseoli, offering a robust species differentiation method. Assessing conidium production required the implementation of five different culture methods. An adaptation of the Scheper et al. (2013) method yielded the highest quantity of conidia from 25 colonies spaced at 1 cm apart, with a conidial yield of 5.0 × 106 conidia per 9-cm-diameter Petri dish. A higher conidial yield was attained after the colonies were pre-incubated on potato dextrose agar in the dark at room temperature for 28 days, followed by a transfer to corn meal agar for an additional 2 days at 20°C. This emphasizes the pivotal influence of incubation duration and pre-culture conditions on the process. This research provides insights into the biology of E. phaseoli and introduces an improved method for enhancing in vitro sporulation of the pathogen, setting groundwork for future research and handling.
{"title":"Identification of Elsinoë phaseoli causing bean scab in Kenya and evaluation of sporulation using five adapted techniques","authors":"Y. O. Masheti, J. W. Muthomi, W. M. Muiru, E. E. Arunga, P. Gepts","doi":"10.1111/jph.13343","DOIUrl":"https://doi.org/10.1111/jph.13343","url":null,"abstract":"<p>This research addresses the presence of <i>Elsinoë phaseoli</i> in Kenya, where information on the biology of this pathogen remains scarce. Employing a multifaceted approach, the study demonstrates the steps taken to isolate, identify, and characterize <i>E. phaseoli</i> as the pathogen responsible for scab on common bean. Field observations confirmed scab symptoms, particularly the prominent pod lesions. <i>Elsinoë phaseoli</i> was isolated from common bean using a targeted streaking method on older acervulus-bearing lesions. Morphological examinations revealed a notable diversity within <i>E. phaseoli</i> colonies, consistent with the characteristics of the genus. Molecular identification through ITS-rDNA sequencing confirmed isolate AscoSK1 obtained in this study as belonging to <i>E. phaseoli</i>, offering a robust species differentiation method. Assessing conidium production required the implementation of five different culture methods. An adaptation of the Scheper et al. (2013) method yielded the highest quantity of conidia from 25 colonies spaced at 1 cm apart, with a conidial yield of 5.0 × 10<sup>6</sup> conidia per 9-cm-diameter Petri dish. A higher conidial yield was attained after the colonies were pre-incubated on potato dextrose agar in the dark at room temperature for 28 days, followed by a transfer to corn meal agar for an additional 2 days at 20°C. This emphasizes the pivotal influence of incubation duration and pre-culture conditions on the process. This research provides insights into the biology of <i>E. phaseoli</i> and introduces an improved method for enhancing in vitro sporulation of the pathogen, setting groundwork for future research and handling.</p>","PeriodicalId":16843,"journal":{"name":"Journal of Phytopathology","volume":"172 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jph.13343","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141430207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cléia Santos Cabral, Alessandro Da Costa Freire Gandara, Fabiana Helena Silva Ribeiro Martins, Elenice Alves Barboza, Maurício Rossato, Ailton Reis
Castor bean (Ricinus communis) is a crop of great economic importance in Brazil. It is used for producing oil used in the manufacture of cosmetics and biodiesel. The genus Phytophthora contains pathogens with a wide range of host plants, including ornamentals, fruit and vegetable crops. Among the symptoms induced by Phytophthora species are collar and root rot. This study aimed to identify Phytophthora species causing collar and root rot in castor bean seedlings in the Federal District and test their pathogenicity. Samples of symptomatic plants were collected in four satellite cities in Distrito Federal, Brazil. Fourteen isolates were obtained, and they were initially identified through the morphology of reproductive structures. The isolates were subjected to molecular characterization using phylogeny of the sequences from the ITS region and the Cytochrome Oxidase II gene. Ten isolates of the pathogen were tested for pathogenicity on seedlings of two castor bean accessions and species known to be hosts of P. nicotianae. The isolates were identified as P. nicotianae (12 isolates) and P. palmivora (two isolates). In the pathogenicity test, all isolates were capable of causing disease in castor beans. The isolates of P. nicotianae and P. palmivora varied in pathogenicity to other plant species. This is the first report of P. nicotianae causing collar and root rot in castor bean in the Central-West Region of Brazil. It is also the first report of P. palmivora causing diseases in castor beans in South America.
蓖麻(Ricinus communis)是巴西一种具有重要经济价值的作物。它被用来生产用于制造化妆品和生物柴油的油。Phytophthora 属包含的病原体寄主植物范围很广,包括观赏植物、水果和蔬菜作物。疫霉菌引起的症状包括领腐病和根腐病。本研究旨在确定在联邦区导致蓖麻秧苗出现领腐和根腐病的疫霉菌种,并测试其致病性。研究人员在巴西联邦区的四个卫星城市采集了有症状的植物样本。获得了 14 个分离株,并通过生殖结构的形态进行了初步鉴定。利用 ITS 区域和细胞色素氧化酶 II 基因序列的系统进化对分离物进行了分子鉴定。对 10 个病原体分离物进行了致病性测试,测试对象是两个蓖麻品种的幼苗,以及已知为烟碱蓖麻菌宿主的物种。经鉴定,这些分离物分别为尼古丁 P.(12 个分离物)和棕榈 P.(2 个分离物)。在致病性试验中,所有分离物都能导致蓖麻发病。P. nicotianae 和 P. palmivora 分离物对其他植物物种的致病性各不相同。这是首次报道 P. nicotianae 在巴西中西部地区引起蓖麻领腐病和根腐病。这也是 P. palmivora 在南美洲引起蓖麻病害的首次报道。
{"title":"Phytophthora species causing root and crown rot on castor bean (Ricinus communis) in Brazil","authors":"Cléia Santos Cabral, Alessandro Da Costa Freire Gandara, Fabiana Helena Silva Ribeiro Martins, Elenice Alves Barboza, Maurício Rossato, Ailton Reis","doi":"10.1111/jph.13337","DOIUrl":"https://doi.org/10.1111/jph.13337","url":null,"abstract":"<p>Castor bean (<i>Ricinus communis</i>) is a crop of great economic importance in Brazil. It is used for producing oil used in the manufacture of cosmetics and biodiesel. The genus <i>Phytophthora</i> contains pathogens with a wide range of host plants, including ornamentals, fruit and vegetable crops. Among the symptoms induced by <i>Phytophthora</i> species are collar and root rot. This study aimed to identify <i>Phytophthora</i> species causing collar and root rot in castor bean seedlings in the Federal District and test their pathogenicity. Samples of symptomatic plants were collected in four satellite cities in Distrito Federal, Brazil. Fourteen isolates were obtained, and they were initially identified through the morphology of reproductive structures. The isolates were subjected to molecular characterization using phylogeny of the sequences from the ITS region and the Cytochrome Oxidase II gene. Ten isolates of the pathogen were tested for pathogenicity on seedlings of two castor bean accessions and species known to be hosts of <i>P. nicotianae</i>. The isolates were identified as <i>P. nicotianae</i> (12 isolates) and <i>P. palmivora</i> (two isolates). In the pathogenicity test, all isolates were capable of causing disease in castor beans. The isolates of <i>P. nicotianae</i> and <i>P. palmivora</i> varied in pathogenicity to other plant species. This is the first report of <i>P. nicotianae</i> causing collar and root rot in castor bean in the Central-West Region of Brazil. It is also the first report of <i>P. palmivora</i> causing diseases in castor beans in South America.</p>","PeriodicalId":16843,"journal":{"name":"Journal of Phytopathology","volume":"172 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141430205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Meltem Avan, Eslam Mohamed Albastawisi, Yağmur Doğa Levent, Sevgi İşlek, Recep Kotan
Postharvest diseases in fruits result in significant losses in the agricultural sector. Among these, green mould, caused by Penicillium digitatum, poses a considerable threat to citrus fruits. This study evaluated the potential of Bacillus amyloliquefaciens strain TV-17C as a biological control agent for managing green mould in oranges. Various concentrations of TV-17C in aqueous suspension were applied to naturally infected orange fruits in the packinghouse at two locations (Hatay and Mersin provinces), while the chemical fungicide fludioxonil 230 SC served as a positive control. The application of B. amyloliquefaciens TV-17C at the dosage of 250 mL 100 L−1 reduced green mould incidence by 90.3% and 89.8% in Hatay and Mersin provinces, respectively. Similarly, fludioxonil 230 SC displayed an efficacy of 91.4% in reducing disease incidence. In summary, this study underscores the potential of B. amyloliquefaciens TV-17C as an efficient biocontrol agent against green mould in oranges. Moreover, a positive correlation between higher concentrations and enhanced efficacy was evident. These findings hold promise for the adoption of sustainable disease management practices in the postharvest citrus industry.
{"title":"Evaluation of Bacillus amyloliquefaciens TV-17C as a potential biocontrol agent for controlling postharvest Penicillium digitatum on orange","authors":"Meltem Avan, Eslam Mohamed Albastawisi, Yağmur Doğa Levent, Sevgi İşlek, Recep Kotan","doi":"10.1111/jph.13345","DOIUrl":"https://doi.org/10.1111/jph.13345","url":null,"abstract":"<p>Postharvest diseases in fruits result in significant losses in the agricultural sector. Among these, green mould, caused by <i>Penicillium digitatum</i>, poses a considerable threat to citrus fruits. This study evaluated the potential of <i>Bacillus amyloliquefaciens</i> strain TV-17C as a biological control agent for managing green mould in oranges. Various concentrations of TV-17C in aqueous suspension were applied to naturally infected orange fruits in the packinghouse at two locations (Hatay and Mersin provinces), while the chemical fungicide fludioxonil 230 SC served as a positive control. The application of <i>B. amyloliquefaciens</i> TV-17C at the dosage of 250 mL 100 L<sup>−1</sup> reduced green mould incidence by 90.3% and 89.8% in Hatay and Mersin provinces, respectively. Similarly, fludioxonil 230 SC displayed an efficacy of 91.4% in reducing disease incidence. In summary, this study underscores the potential of <i>B. amyloliquefaciens</i> TV-17C as an efficient biocontrol agent against green mould in oranges. Moreover, a positive correlation between higher concentrations and enhanced efficacy was evident. These findings hold promise for the adoption of sustainable disease management practices in the postharvest citrus industry.</p>","PeriodicalId":16843,"journal":{"name":"Journal of Phytopathology","volume":"172 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141430204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The impact of eight pesticides on the transmission of Tomato leaf curl virus (ToLCV) by the whitefly, Bemisia tabaci Gennadius to tomato, Lycopersicon esculentum (Miller), was studied in the field using a randomized block design. Differences in performance were anticipated because these eight insecticides comprise distinct mechanism of action including both contact and systemic. Increased insecticide efficacy is necessary, particularly in regions with conducive weather conditions that support a healthy whitefly population, to effectively manage the population. There is a need to vary the insecticides used in order to reduce the emergence of resistance in the whitefly population due to the extensive usage of a single mechanism of action for whitefly control. The foliar spray of insecticides was done when first incidence of whitefly was noticed in the field with 15 days of interval. The studies on effect of different insecticides in the management of ToLCV disease through the controlling whitefly population, we evaluated that Chlorantraniliprole 8.8% + Thiomethaxam 17.5% SC was effective in sustaining the yield by reducing the incidence of disease and whitefly population during both the years followed by Spirotetramat 11.01% + Imidacloprid 11.01% SC, Thiamethoxam 12.6% + Lambda cyhalothrin 9.5% ZC and Cyantraniliprole 10.26% OD, respectively.
{"title":"Efficacy assessment of different insecticides for control of whitefly against tomato leaf curl disease","authors":"Someshree Mane, Pravin Khaire, Ashwini Kumar, Tanaji Narute","doi":"10.1111/jph.13340","DOIUrl":"https://doi.org/10.1111/jph.13340","url":null,"abstract":"<p>The impact of eight pesticides on the transmission of Tomato leaf curl virus (ToLCV) by the whitefly, <i>Bemisia tabaci</i> Gennadius to tomato, <i>Lycopersicon esculentum</i> (Miller), was studied in the field using a randomized block design. Differences in performance were anticipated because these eight insecticides comprise distinct mechanism of action including both contact and systemic. Increased insecticide efficacy is necessary, particularly in regions with conducive weather conditions that support a healthy whitefly population, to effectively manage the population. There is a need to vary the insecticides used in order to reduce the emergence of resistance in the whitefly population due to the extensive usage of a single mechanism of action for whitefly control. The foliar spray of insecticides was done when first incidence of whitefly was noticed in the field with 15 days of interval. The studies on effect of different insecticides in the management of ToLCV disease through the controlling whitefly population, we evaluated that Chlorantraniliprole 8.8% + Thiomethaxam 17.5% SC was effective in sustaining the yield by reducing the incidence of disease and whitefly population during both the years followed by Spirotetramat 11.01% + Imidacloprid 11.01% SC, Thiamethoxam 12.6% + Lambda cyhalothrin 9.5% ZC and Cyantraniliprole 10.26% OD, respectively.</p>","PeriodicalId":16843,"journal":{"name":"Journal of Phytopathology","volume":"172 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141425009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pablo H. Teixeira, Renan C. Lima, Trazilbo J. Paula Jr., José Eustáquio S. Carneiro, Heder Braun, Júlia E. A. Silva, Rogério F. Vieira
In a previous study, common bean (Phaseolus vulgaris L.) genotypes were selected in the field for reactions to white mould (WM), caused by Sclerotinia sclerotiorum. These genotypes, along with the resistant control A195, were then evaluated in both field and greenhouse (straw test) conditions. The results showed that field trials effectively identified high-yielding WM-resistant genotypes for dry-irrigated conditions. Here we challenge the results of this study with new data and methodology by conducting six sprinkler-irrigated trials from 2015 to 2017 with five genotype groups (G). Three groups comprised genotypes previously studied: G1, seven partially resistant; G4, two intermediately resistant; and G5, three susceptible. G2 consisted of four lines selected for partial resistance in the current study. The resistant control group, G3, comprised the genotypes A195, G122, Cornell605, and Ouro Branco. WM was absent (one trial), or pressure was either low/moderate (two trials) or moderate/high (three trials). The average seed yield ranged from 2207 (G3) to 3178 kg/ha (G1). The contrast G1, G2 versus G3 was nonsignificant for incidence and severity index, indicating that genotypes selected for resistance in the field were as resistant as the resistant control genotypes. Additionally, the groups selected for resistance yielded 43% more and produced 33% less sclerotia weight compared with the control group. Our results reinforce the effectiveness of selecting WM-resistant genotypes using beans originally bred for purposes other than WM-resistance, specifically targeting dry-irrigated areas. Furthermore, our results suggest that the use of genotypes selected for partial resistance reduces inoculum levels in the soil.
{"title":"Strategy to identify common beans with resistance to white mould for dry-irrigated areas: Additional evidence","authors":"Pablo H. Teixeira, Renan C. Lima, Trazilbo J. Paula Jr., José Eustáquio S. Carneiro, Heder Braun, Júlia E. A. Silva, Rogério F. Vieira","doi":"10.1111/jph.13335","DOIUrl":"https://doi.org/10.1111/jph.13335","url":null,"abstract":"<p>In a previous study, common bean (<i>Phaseolus vulgaris</i> L.) genotypes were selected in the field for reactions to white mould (WM), caused by <i>Sclerotinia sclerotiorum</i>. These genotypes, along with the resistant control A195, were then evaluated in both field and greenhouse (straw test) conditions. The results showed that field trials effectively identified high-yielding WM-resistant genotypes for dry-irrigated conditions. Here we challenge the results of this study with new data and methodology by conducting six sprinkler-irrigated trials from 2015 to 2017 with five genotype groups (G). Three groups comprised genotypes previously studied: G1, seven partially resistant; G4, two intermediately resistant; and G5, three susceptible. G2 consisted of four lines selected for partial resistance in the current study. The resistant control group, G3, comprised the genotypes A195, G122, Cornell605, and Ouro Branco. WM was absent (one trial), or pressure was either low/moderate (two trials) or moderate/high (three trials). The average seed yield ranged from 2207 (G3) to 3178 kg/ha (G1). The contrast G1, G2 versus G3 was nonsignificant for incidence and severity index, indicating that genotypes selected for resistance in the field were as resistant as the resistant control genotypes. Additionally, the groups selected for resistance yielded 43% more and produced 33% less sclerotia weight compared with the control group. Our results reinforce the effectiveness of selecting WM-resistant genotypes using beans originally bred for purposes other than WM-resistance, specifically targeting dry-irrigated areas. Furthermore, our results suggest that the use of genotypes selected for partial resistance reduces inoculum levels in the soil.</p>","PeriodicalId":16843,"journal":{"name":"Journal of Phytopathology","volume":"172 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141326737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. M. Oliveira, E. A. Pozza, L. L. Belan, M. L. O. Freitas, V. M. Tedardi
Bacterial halo blight (BHB), caused by Pseudomonas coronafaciens pv. garcae (Pcg), is one of the most significant diseases affecting coffee trees worldwide, resulting in considerable damage and notable losses within coffee production systems. Further research into the epidemiology and aetiology of BHB in coffee plants is essential for developing effective management strategies. Understanding the efficiency of each inoculation methodology in inducing symptoms is crucial for advancing this research. Therefore, this study aimed to assess the efficiency of seven Pcg inoculation methods using five concentrations to enhance the highest BHB intensity. The experimental design was a complete randomized block design in a factorial (7 × 5) variance analysis with four replications. The first three pairs of leaves of coffee seedlings of the cultivar Catuaí Vermelho IAC-99 were inoculated and evaluated for the incidence and severity of BHB. The inoculation methods of Pcg by injury provided higher BHB AUDPCI and AUDPCS values. Among these, the inoculum injection and multi-needle wounding at inoculum concentrations of 1.6 × 109 CFU mL−1 demonstrated higher disease intensity.
{"title":"Efficiency of inoculation methods for the assessment of bacterial halo blight in coffee seedlings","authors":"J. M. Oliveira, E. A. Pozza, L. L. Belan, M. L. O. Freitas, V. M. Tedardi","doi":"10.1111/jph.13336","DOIUrl":"https://doi.org/10.1111/jph.13336","url":null,"abstract":"<p>Bacterial halo blight (BHB), caused by <i>Pseudomonas coronafaciens</i> pv. <i>garcae</i> (Pcg), is one of the most significant diseases affecting coffee trees worldwide, resulting in considerable damage and notable losses within coffee production systems. Further research into the epidemiology and aetiology of BHB in coffee plants is essential for developing effective management strategies. Understanding the efficiency of each inoculation methodology in inducing symptoms is crucial for advancing this research. Therefore, this study aimed to assess the efficiency of seven Pcg inoculation methods using five concentrations to enhance the highest BHB intensity. The experimental design was a complete randomized block design in a factorial (7 × 5) variance analysis with four replications. The first three pairs of leaves of coffee seedlings of the cultivar Catuaí Vermelho IAC-99 were inoculated and evaluated for the incidence and severity of BHB. The inoculation methods of Pcg by injury provided higher BHB AUDPCI and AUDPCS values. Among these, the inoculum injection and multi-needle wounding at inoculum concentrations of 1.6 × 10<sup>9</sup> CFU mL<sup>−1</sup> demonstrated higher disease intensity.</p>","PeriodicalId":16843,"journal":{"name":"Journal of Phytopathology","volume":"172 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141326738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elenice Alves Barboza, Luiz Henrique Rocha Lopes, Carmen Lidia Amorim Pires-Zottarelli, Cléia Santos Cabral, Willie Anderson dos Santos Vieira, Maurício Rossato, Fabiana Helena Silva Ribeiro, Ailton Reis
Pythium tracheiphilum is a narrow host range oomycete first described infecting lettuce in Italy. Subsequently, the pathogen was reported in many other countries. From 2015 to 2019, Pythium isolates were recovered from lettuce plants with symptoms of leaf rot, wilting and vascular necrosis, collected from commercial fields in different rural localities of Brasilia-DF, Brazil. The isolates were identified as P. tracheiphilum based on morphological and molecular genetic analysis. Pathogenicity tests conducted with four P. tracheiphilum isolates confirmed that the isolates were pathogenic to detached leaves of a loose-hearted lettuce cultivar. This is the first report of P. tracheiphilum infecting lettuces in Brazil.
Pythium tracheiphilum 是一种寄主范围很窄的卵菌,最早出现在意大利的莴苣上。随后,许多其他国家也报道了这种病原体。2015 年至 2019 年期间,从巴西巴西利亚联邦区(Brasilia-DF)不同农村地区的商品田中采集到的具有叶片腐烂、枯萎和维管束坏死症状的莴苣植株中回收了腐霉菌分离株。根据形态学和分子遗传学分析,这些分离物被鉴定为 P. tracheiphilum。对 4 个 P. tracheiphilum 分离物进行的致病性试验证实,这些分离物对松心莴苣品种的脱落叶片具有致病性。这是巴西首次报道 P. tracheiphilum 感染莴苣。
{"title":"Pythium tracheiphilum causing leaf rot and wilting in lettuce in Brasília-DF, Brazil","authors":"Elenice Alves Barboza, Luiz Henrique Rocha Lopes, Carmen Lidia Amorim Pires-Zottarelli, Cléia Santos Cabral, Willie Anderson dos Santos Vieira, Maurício Rossato, Fabiana Helena Silva Ribeiro, Ailton Reis","doi":"10.1111/jph.13334","DOIUrl":"https://doi.org/10.1111/jph.13334","url":null,"abstract":"<p><i>Pythium tracheiphilum</i> is a narrow host range oomycete first described infecting lettuce in Italy. Subsequently, the pathogen was reported in many other countries. From 2015 to 2019, <i>Pythium</i> isolates were recovered from lettuce plants with symptoms of leaf rot, wilting and vascular necrosis, collected from commercial fields in different rural localities of Brasilia-DF, Brazil. The isolates were identified as <i>P. tracheiphilum</i> based on morphological and molecular genetic analysis. Pathogenicity tests conducted with four <i>P. tracheiphilum</i> isolates confirmed that the isolates were pathogenic to detached leaves of a loose-hearted lettuce cultivar. This is the first report of <i>P. tracheiphilum</i> infecting lettuces in Brazil.</p>","PeriodicalId":16843,"journal":{"name":"Journal of Phytopathology","volume":"172 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141326739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fusarium oxysporum f.sp. conglutinans (FOC) causes yellow wilt, a serious cabbage disease. This fungal species is composed of many strains within two pathotypes. In this study, the inhibitory effect of essential oils of six aromatic and medicinal plants (oregano, thyme, clove, cinnamon, lemongrass, litsea) at multiple concentrations on eight FOC isolates of different origins was investigated. Our results showed that oregano essential oil had the greatest inhibitory effect. The tested essential oils could be divided into three clusters according to the similar content of their main components (oregano and thyme, clove and cinnamon, lemongrass, and litsea), which correlated to some extent with their inhibitory effects on FOC. The tested isolates also differed in their response to the studied essential oils. The differences within FOC races were more important than between races, and the sensitivity of isolates against essential oils seemed to be more related to the geographical origin of the isolates, rather than to their race affiliation.
{"title":"Diversity in the growth response of isolates of Fusarium oxysporum f.sp. conglutinans to different essential oils","authors":"Stepan Helmer, Matej Panek","doi":"10.1111/jph.13332","DOIUrl":"https://doi.org/10.1111/jph.13332","url":null,"abstract":"<p><i>Fusarium oxysporum</i> f.sp. <i>conglutinans</i> (FOC) causes yellow wilt, a serious cabbage disease. This fungal species is composed of many strains within two pathotypes. In this study, the inhibitory effect of essential oils of six aromatic and medicinal plants (oregano, thyme, clove, cinnamon, lemongrass, litsea) at multiple concentrations on eight FOC isolates of different origins was investigated. Our results showed that oregano essential oil had the greatest inhibitory effect. The tested essential oils could be divided into three clusters according to the similar content of their main components (oregano and thyme, clove and cinnamon, lemongrass, and litsea), which correlated to some extent with their inhibitory effects on FOC. The tested isolates also differed in their response to the studied essential oils. The differences within FOC races were more important than between races, and the sensitivity of isolates against essential oils seemed to be more related to the geographical origin of the isolates, rather than to their race affiliation.</p>","PeriodicalId":16843,"journal":{"name":"Journal of Phytopathology","volume":"172 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jph.13332","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141326736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rudy Hermanto, Rudi Hari Murti, Sedyo Hartono, Azis Purwantoro, Arman Wijonarko, Mulyantoro, Hartinio Natalia Nahampun, Ahmad Afifuddin
Yellow mosaic and leaf curl diseases caused by whitefly-transmitted begomo virus genera are important problems in tomato (Solanum lycopersicon L.) production in Indonesia, particularly on Java Island. The aims of this survey are to assess the percentages of disease incidence (DI) and disease severity index (DSI), evaluate the spread and complexity of begomovirus and crinivirus infections responsible for yellow mosaic and leaf curl diseases in tomato plants, and identify the species of whitefly insect vectors and their cryptic biotypes in tomato production centers located on Java Island, Indonesia. A total of 43 locations in East, Central, and West Java were surveyed during the dry season from July 2022 to September 2022. Disease incidence and severity were determined by observing 200 samples of tomato plants from five points at each location, with 40 plants per point of land. A total of 116 whitefly samples in microtubes and 215 symptomatic leaf samples were collected. The genus begomovirus and crinivirus infecting tomato were identified by PCR and RT-PCR using genus-specific primers. Similarly, whitefly species and their cryptic biotypes were identified by PCR using MCoI gene-specific primers. Results showed that DI and DSI remarkably differed between the lowlands (66%–89%) and highlands (33%–62%) in the provinces of Central Java and West Java. Furthermore, PCR analysis of 215 infected tomato showing the symptoms of yellow mosaic and curly leaf revealed that three begomoviruses, one crinivirus and their mixed combination both begomoviruses, one crinivirus has been detected in all the samples. Similarly, the whitefly insect vector Bemisia tabaci biotype Q was identified in all areas, whereas Trialeurodes vaporariorum was found only in the East Java and Java highlands, respectively.
{"title":"Viral complexity of tomatoes yellow mosaic and leaf curl diseases in lowland and highland areas","authors":"Rudy Hermanto, Rudi Hari Murti, Sedyo Hartono, Azis Purwantoro, Arman Wijonarko, Mulyantoro, Hartinio Natalia Nahampun, Ahmad Afifuddin","doi":"10.1111/jph.13326","DOIUrl":"https://doi.org/10.1111/jph.13326","url":null,"abstract":"<p>Yellow mosaic and leaf curl diseases caused by whitefly-transmitted begomo virus genera are important problems in tomato (<i>Solanum lycopersicon</i> L.) production in Indonesia, particularly on Java Island. The aims of this survey are to assess the percentages of disease incidence (DI) and disease severity index (DSI), evaluate the spread and complexity of begomovirus and crinivirus infections responsible for yellow mosaic and leaf curl diseases in tomato plants, and identify the species of whitefly insect vectors and their cryptic biotypes in tomato production centers located on Java Island, Indonesia. A total of 43 locations in East, Central, and West Java were surveyed during the dry season from July 2022 to September 2022. Disease incidence and severity were determined by observing 200 samples of tomato plants from five points at each location, with 40 plants per point of land. A total of 116 whitefly samples in microtubes and 215 symptomatic leaf samples were collected. The genus begomovirus and crinivirus infecting tomato were identified by PCR and RT-PCR using genus-specific primers. Similarly, whitefly species and their cryptic biotypes were identified by PCR using MCoI gene-specific primers. Results showed that DI and DSI remarkably differed between the lowlands (66%–89%) and highlands (33%–62%) in the provinces of Central Java and West Java. Furthermore, PCR analysis of 215 infected tomato showing the symptoms of yellow mosaic and curly leaf revealed that three begomoviruses, one crinivirus and their mixed combination both begomoviruses, one crinivirus has been detected in all the samples. Similarly, the whitefly insect vector <i>Bemisia tabaci</i> biotype Q was identified in all areas, whereas <i>Trialeurodes vaporariorum</i> was found only in the East Java and Java highlands, respectively.</p>","PeriodicalId":16843,"journal":{"name":"Journal of Phytopathology","volume":"172 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jph.13326","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141298406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xianren Xia, Quanzhen Wang, Kai Guo, GuoQin Yuan, Tao Deng, Zhenyu Zhao, Qichao Guo, Kai Wu, Biao Chen, Yihong Pan
Tobacco black shank (TBS) and tobacco root black rot (TRBR) are two of the most devastating tobacco soil-borne diseases that threaten sustainable tobacco planting. This study investigated the effects of Trichoderma sp. and a resistance inducer (RI) extracted from traditional Chinese medicine, individually or in combination, on the control of TBS and TRBR. The results showed that the application of Trichoderma sp. and RI, individually or in combination, significantly controlled the two soil-borne diseases by significantly affecting the bacterial, but not fungal, Shannon and Simpson diversity indexes. The disease indexes of TBS and TRBR in integrated application management were the lowest, resulting in the highest potassium contents in the tobacco leaves. The control efficacies of TBS and TRBR in the integrated application treatment were 71.52 ± 1.43% and 68.33 ± 0.69%, respectively. The integrated treatment altered the composition of the rhizosphere soil microbial community. The bacterial community, but not the fungal community, of the control treatment was separated from those of other treatments. The relative abundance of bacteria involved in chemoheterotrophy and fermentation in the control treatment increased, whereas that of bacteria involved in nitrification and aerobic ammonia oxidation decreased compared with the other treatments. Importantly, the application of Trichoderma sp. and RI, individually or in combination, clearly increased the relative abundance of saprotrophic fungi in contrast to the control treatment, while decreasing that of pathotrophic fungi. Our study suggests that a suitable integrated application of bioagents and RI has synergistic effects on the suppression of two tobacco soil-borne diseases by altering the rhizosphere microbiome composition in the field.
烟草黑柄病(TBS)和烟草根黑腐病(TRBR)是威胁烟草可持续种植的两种最具破坏性的烟草土传病害。本研究探讨了单独或联合使用毛霉和从中药中提取的抗性诱导剂(RI)对烟草黑柄病和烟草根黑腐病的防治效果。结果表明,单独或联合施用毛霉和抗性诱导剂可显著控制这两种土传病害,对细菌(而非真菌)的香农(Shannon)和辛普森(Simpson)多样性指数有明显影响。在综合施药管理中,TBS 和 TRBR 的病害指数最低,因此烟叶中的钾含量最高。在综合施药处理中,TBS 和 TRBR 的防治效果分别为 71.52 ± 1.43% 和 68.33 ± 0.69%。综合处理改变了根圈土壤微生物群落的组成。对照处理的细菌群落与其他处理的细菌群落分开,但真菌群落没有分开。与其他处理相比,对照处理中参与化合营养和发酵的细菌相对丰度增加,而参与硝化和需氧氨氧化的细菌相对丰度减少。重要的是,与对照处理相比,单独或联合施用毛霉和 RI 明显增加了嗜根真菌的相对丰度,而减少了嗜病真菌的相对丰度。我们的研究表明,适当综合应用生物制剂和 RI 可通过改变田间根瘤微生物组的组成,对抑制两种烟草土传病害产生协同效应。
{"title":"Combined application of resistance inducer and Trichoderma control two tobacco soil-borne diseases by regulating the field soil microbial composition","authors":"Xianren Xia, Quanzhen Wang, Kai Guo, GuoQin Yuan, Tao Deng, Zhenyu Zhao, Qichao Guo, Kai Wu, Biao Chen, Yihong Pan","doi":"10.1111/jph.13333","DOIUrl":"https://doi.org/10.1111/jph.13333","url":null,"abstract":"<p>Tobacco black shank (TBS) and tobacco root black rot (TRBR) are two of the most devastating tobacco soil-borne diseases that threaten sustainable tobacco planting. This study investigated the effects of <i>Trichoderma</i> sp. and a resistance inducer (RI) extracted from traditional Chinese medicine, individually or in combination, on the control of TBS and TRBR. The results showed that the application of <i>Trichoderma</i> sp. and RI, individually or in combination, significantly controlled the two soil-borne diseases by significantly affecting the bacterial, but not fungal, Shannon and Simpson diversity indexes. The disease indexes of TBS and TRBR in integrated application management were the lowest, resulting in the highest potassium contents in the tobacco leaves. The control efficacies of TBS and TRBR in the integrated application treatment were 71.52 ± 1.43% and 68.33 ± 0.69%, respectively. The integrated treatment altered the composition of the rhizosphere soil microbial community. The bacterial community, but not the fungal community, of the control treatment was separated from those of other treatments. The relative abundance of bacteria involved in chemoheterotrophy and fermentation in the control treatment increased, whereas that of bacteria involved in nitrification and aerobic ammonia oxidation decreased compared with the other treatments. Importantly, the application of <i>Trichoderma</i> sp. and RI, individually or in combination, clearly increased the relative abundance of saprotrophic fungi in contrast to the control treatment, while decreasing that of pathotrophic fungi. Our study suggests that a suitable integrated application of bioagents and RI has synergistic effects on the suppression of two tobacco soil-borne diseases by altering the rhizosphere microbiome composition in the field.</p>","PeriodicalId":16843,"journal":{"name":"Journal of Phytopathology","volume":"172 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141298404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}