K. Alraiss, A. Fowkes, L. Frew, G. Webster, A. Skelton, C. Conyers, B. Barrett, I. Adams, S. McGreig, M. Mynett, K. Chisnall, R. Ward, M. Dixon, S. Forde, Z. Golding, J. Bailey, V. Pugliese, S. K. Waziri, T. Alicai, A. Fox
{"title":"First report of Tamarillo fruit ring virus in Solanum spp. in Uganda, Tanzania and Rwanda","authors":"K. Alraiss, A. Fowkes, L. Frew, G. Webster, A. Skelton, C. Conyers, B. Barrett, I. Adams, S. McGreig, M. Mynett, K. Chisnall, R. Ward, M. Dixon, S. Forde, Z. Golding, J. Bailey, V. Pugliese, S. K. Waziri, T. Alicai, A. Fox","doi":"10.1002/ndr2.12256","DOIUrl":"https://doi.org/10.1002/ndr2.12256","url":null,"abstract":"","PeriodicalId":36931,"journal":{"name":"New Disease Reports","volume":"26 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140524063","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}
{"title":"First report of Ti ringspot‐associated virus infecting peach in Greece","authors":"D. Beris, I. Malandraki, C. Varveri","doi":"10.1002/ndr2.12240","DOIUrl":"https://doi.org/10.1002/ndr2.12240","url":null,"abstract":"","PeriodicalId":36931,"journal":{"name":"New Disease Reports","volume":"3 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139631786","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}
During a survey in May 2019, lentil (Lens culinaris cv. Syria 229) plants cultivated in an open field in Tiaret, Algeria showed chlorotic leaf spots with an incidence of about 10%. The symptoms began as small, irregular lesions and expanded with time from the edge to the centre of the leaves. To identify the causal agent, diseased leaves were disinfected in 2% NaOCl for three minutes, rinsed thrice with sterile water, plated onto potato dextrose agar and incubated at 25±1°C for seven days. Fungal colonies were dark grey with dense growth. Conidiophores were brown, erect, simple or branched, 2.5-3.75 × 21–42.5 μm. Conidia were mostly ovoid or ellipsoidal, light to dark brown with 1 to 3 transverse septa and 0 to 2 longitudinal septa and ranged in size from 8.75-17.5 × 7.5-15 μm (n = 25) (Fig. 1). Based on morphological characters, isolates were identified as Alternaria sp. (Simmons, 2007). To confirm the identity of the fungus, a PCR was done to amplify ITS and tef1 regions of a representative isolate, ST2 (White et al., 1990; Carbone & Kohn, 1999). The obtained sequences (GenBank Accession Nos. OQ256241, OQ269665) were analysed with BLASTn and had 99.58 and 99.52% identity, 479/481(99%) and 209/210 (99%) pairs matching, with the ex-type sequences of Alternaria cantlous (CBS 123007) for ITS (KC584245) and tef1 (KC584739), respectively. Phylogenetic analysis of concatenated sequences of ITS and tef1 using the maximum likelihood method, clustered isolate ST2 consistently with the ex-type strain of Alternaria cantlous (Yong Wang bis & X.G. Zhang) (Woudenberg et al., 2013), with bootstrap support of 96% (Fig. 2). Based on the BLAST search and phylogenetic analysis, isolate ST2 was identified as Alternaria cantlous. A pathogenicity test was performed under greenhouse conditions by spraying a conidial suspension of 105 conidia/ml onto mature leaves of three lentil (cv. Syria 229) plants. Control plants were sprayed with sterile water. All plants were covered with a transparent plastic bag for 72 hours. After 20 days, the inoculated plants showed similar symptoms to those observed in the field (Fig. 3), while no symptoms were observed on control plants. The fungus was reisolated from all inoculated plants to fulfill Koch's postulates. To the best of our knowledge this is the first report of A. cantlous causing leaf spot on lentil in Algeria and worldwide. The authors wish to express their sincerest gratitude to Professor Madani Benouycef from University Mustapha Stambouli of Mascara, Department of Earth Sciences for providing the necessary facilities and equipment for the research work.
{"title":"The first report of <i>Alternaria cantlous</i> causing leaf spot on lentil (<i>Lens culinaris</i>)","authors":"M. E. A. Kouadri, A. A. Bekkar, S. Zaim","doi":"10.1002/ndr2.12220","DOIUrl":"https://doi.org/10.1002/ndr2.12220","url":null,"abstract":"During a survey in May 2019, lentil (Lens culinaris cv. Syria 229) plants cultivated in an open field in Tiaret, Algeria showed chlorotic leaf spots with an incidence of about 10%. The symptoms began as small, irregular lesions and expanded with time from the edge to the centre of the leaves. To identify the causal agent, diseased leaves were disinfected in 2% NaOCl for three minutes, rinsed thrice with sterile water, plated onto potato dextrose agar and incubated at 25±1°C for seven days. Fungal colonies were dark grey with dense growth. Conidiophores were brown, erect, simple or branched, 2.5-3.75 × 21–42.5 μm. Conidia were mostly ovoid or ellipsoidal, light to dark brown with 1 to 3 transverse septa and 0 to 2 longitudinal septa and ranged in size from 8.75-17.5 × 7.5-15 μm (n = 25) (Fig. 1). Based on morphological characters, isolates were identified as Alternaria sp. (Simmons, 2007). To confirm the identity of the fungus, a PCR was done to amplify ITS and tef1 regions of a representative isolate, ST2 (White et al., 1990; Carbone & Kohn, 1999). The obtained sequences (GenBank Accession Nos. OQ256241, OQ269665) were analysed with BLASTn and had 99.58 and 99.52% identity, 479/481(99%) and 209/210 (99%) pairs matching, with the ex-type sequences of Alternaria cantlous (CBS 123007) for ITS (KC584245) and tef1 (KC584739), respectively. Phylogenetic analysis of concatenated sequences of ITS and tef1 using the maximum likelihood method, clustered isolate ST2 consistently with the ex-type strain of Alternaria cantlous (Yong Wang bis & X.G. Zhang) (Woudenberg et al., 2013), with bootstrap support of 96% (Fig. 2). Based on the BLAST search and phylogenetic analysis, isolate ST2 was identified as Alternaria cantlous. A pathogenicity test was performed under greenhouse conditions by spraying a conidial suspension of 105 conidia/ml onto mature leaves of three lentil (cv. Syria 229) plants. Control plants were sprayed with sterile water. All plants were covered with a transparent plastic bag for 72 hours. After 20 days, the inoculated plants showed similar symptoms to those observed in the field (Fig. 3), while no symptoms were observed on control plants. The fungus was reisolated from all inoculated plants to fulfill Koch's postulates. To the best of our knowledge this is the first report of A. cantlous causing leaf spot on lentil in Algeria and worldwide. The authors wish to express their sincerest gratitude to Professor Madani Benouycef from University Mustapha Stambouli of Mascara, Department of Earth Sciences for providing the necessary facilities and equipment for the research work.","PeriodicalId":36931,"journal":{"name":"New Disease Reports","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135656202","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}
A. Ozolina, C. J. Field, H. M. Beaton, C. Cunningham, A. V. Barnes
{"title":"First report of <i>Colletotrichum liriopes</i> on <i>Liriope muscari</i> (lily turf) in the United Kingdom","authors":"A. Ozolina, C. J. Field, H. M. Beaton, C. Cunningham, A. V. Barnes","doi":"10.1002/ndr2.12222","DOIUrl":"https://doi.org/10.1002/ndr2.12222","url":null,"abstract":"","PeriodicalId":36931,"journal":{"name":"New Disease Reports","volume":"133 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136153336","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}
L. M. Madrassi, R. D. González, C. I. Mónaco, P. Zapata, A. E. Alvarenga
{"title":"Clonostachys chloroleuca: A novel pathogen causing cassava root rot disease in Misiones Province, Argentina","authors":"L. M. Madrassi, R. D. González, C. I. Mónaco, P. Zapata, A. E. Alvarenga","doi":"10.1002/ndr2.12229","DOIUrl":"https://doi.org/10.1002/ndr2.12229","url":null,"abstract":"","PeriodicalId":36931,"journal":{"name":"New Disease Reports","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139325081","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}
{"title":"Stenotrophomonas sp. associated with offshoot decline of date palm in Iran","authors":"A. Abedinzadeh, N. Falahi Charkhabi, M. Aeini","doi":"10.1002/ndr2.12228","DOIUrl":"https://doi.org/10.1002/ndr2.12228","url":null,"abstract":"","PeriodicalId":36931,"journal":{"name":"New Disease Reports","volume":"196 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139325632","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}
S. Hlaiem, I. Yangui, H. Khadraoui, M. Jamâa, O. Ezzine
{"title":"First report of Diplodia seriata associated with branch canker dieback on Cupressus sempervirens in Tunisia","authors":"S. Hlaiem, I. Yangui, H. Khadraoui, M. Jamâa, O. Ezzine","doi":"10.1002/ndr2.12234","DOIUrl":"https://doi.org/10.1002/ndr2.12234","url":null,"abstract":"","PeriodicalId":36931,"journal":{"name":"New Disease Reports","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139326751","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}
P. Sonavane, K. Hima Bindu, V. Venkataravanappa, S. Sriram, None Shivakumar
Bhringraj (false daisy, family Asteraceae) is a valuable herb commonly used in ayurvedic and traditional medicine in the Indian subcontinent (Jahan et al., 2014); the leaf extract has antibacterial, antifungal and antiviral activity (Dalal et al., 2010). In experimental plots of false daisy at the ICAR-Indian Institute of Horticultural Research in Bengaluru, Karnataka, India, symptoms of severe downy growth were observed in September 2022 (post monsoon season). In the initial stage of infection, leaves showed yellowing and necrosis on adaxial surfaces and sparse mycelia growth was observed on the abaxial surface of older leaves. Later, thick white mycelial growth was observed on the lower side of young leaves (Figure 1). As the disease progressed, leaves dried and turned brown, then blackened, leading to 80–100 % loss in yield. One infected leaf was collected from each of three plants for further examination and pathogen identification. Microscopic observation revealed downy growth on the abaxial surface of leaves with numerous sporangia. The mycelium was hyaline, aseptate and branched, 5–15 μm in diameter. Sporangiophores were slender with monopodial branching at right angles and with a slight bulbous base. The sporangia were hyaline, smooth, globose to ellipsoidal with apical papilla and basal hilum on three sterigma, measuring 18–30 × 14–20 µm (Figure 2). Based on these characteristics, the pathogen was identified as Plasmopara sphagneticolae (Davis et al., 2020; Wang et al., 2021). To confirm the identity of the pathogen, total DNA was isolated from two of the samples (PSB-1 and PSB-2) using the CTAB method and the COX 2 region was amplified using primers Cox2F and Cox2R (Hudspeth et al., 2000). Analysis of the sequences using BLASTn showed the highest identity to P. sphagneticolae isolates BRIP61010 and BPI919166 (Genbank Accession Nos. KM085175 and MT292790, respectively). The consensus sequences were submitted to Genbank (OQ200475 and OQ200476). Phylogenetic analysis showed that the sequences of PSB-1 and PSB-2 clustered closely with isolates of P. sphagneticolae. Both P. sphagneticolae and its sister species P. halstedii cause downy mildew on many crops in the Asteraceae. Plasmopara sphagneticolae was first identified in Australia infecting Sphagenticola trilobata (McTaggart et al., 2015), and was then found on Lipochaeta integrifolia in Hawaii (Davis et al., 2020) and Taiwan (Wang et al., 2021). This is the first report of P. sphagneticolae in India and the first record of this pathogen causing downy mildew on bhringraj. The authors are grateful to the Director, Indian Institute of Horticultural Research, Bangalore. Financial assistance to K. Hima Bindu from NMPB, India (Project No; Z. 18017) is acknowledged.
Bhringraj(假雏菊,菊科)是印度次大陆阿育吠陀和传统医学中常用的一种珍贵草药(Jahan等人,2014);叶提取物具有抗菌、抗真菌和抗病毒活性(Dalal et al., 2010)。在位于印度卡纳塔克邦班加罗尔的icar -印度园艺研究所的假雏菊试验田中,在2022年9月(季风季节后)观察到严重的绒毛生长症状。侵染初期,叶片正面泛黄坏死,老叶背面菌丝生长稀疏。随后,在幼叶的下侧观察到粗大的白色菌丝生长(图1)。随着疾病的发展,叶片变干变褐色,然后变黑,导致产量损失80 - 100%。3株植物各取1片感染叶片作进一步检查和病原菌鉴定。镜下观察叶背面有绒毛状生长,孢子囊众多。菌丝体透明,无菌丝,分枝,直径5 ~ 15 μm。孢子囊孢子纤细,单足分枝成直角,基部有轻微球茎。孢子囊呈透明状,光滑,球形至椭球状,三个柱头上有顶乳头和基门,尺寸为18-30 × 14-20µm(图2)。根据这些特征,鉴定为sphagneticolae (Davis et al., 2020;Wang等人,2021)。为了确认病原体的身份,使用CTAB法从两个样本(PSB-1和PSB-2)中分离总DNA,并使用引物COX 2f和COX 2r扩增COX 2区域(Hudspeth et al., 2000)。利用BLASTn对该序列进行分析,结果表明该序列与sphagneticolae分离株BRIP61010和BPI919166 (Genbank登录号分别为KM085175和MT292790)的同源性最高。将一致序列提交到Genbank (OQ200475和OQ200476)。系统发育分析表明,PSB-1和PSB-2序列与sphagneticolae分离株具有紧密的聚类关系。无论是P. sphagneticolae和它的姐妹种P. halstedii引起霜霉病在许多作物的菊科。sphagneticolae Plasmopara Sphagenticola trilobata首先在澳大利亚被发现(McTaggart et al., 2015),随后在夏威夷(Davis et al., 2020)和台湾(Wang et al., 2021)的Lipochaeta integrifolia上被发现。这是印度首次报道的sphagneticolae,也是该病原菌引起霜霉病的首次记录。作者感谢印度班加罗尔园艺研究所所长。印度NMPB对K. Hima Bindu的财政援助(项目编号;Z. 18017)得到确认。
{"title":"First report of <i>Plasmopara sphagneticolae</i> causing downy mildew on bhringraj (<i>Eclipta alba</i>) in India","authors":"P. Sonavane, K. Hima Bindu, V. Venkataravanappa, S. Sriram, None Shivakumar","doi":"10.1002/ndr2.12221","DOIUrl":"https://doi.org/10.1002/ndr2.12221","url":null,"abstract":"Bhringraj (false daisy, family Asteraceae) is a valuable herb commonly used in ayurvedic and traditional medicine in the Indian subcontinent (Jahan et al., 2014); the leaf extract has antibacterial, antifungal and antiviral activity (Dalal et al., 2010). In experimental plots of false daisy at the ICAR-Indian Institute of Horticultural Research in Bengaluru, Karnataka, India, symptoms of severe downy growth were observed in September 2022 (post monsoon season). In the initial stage of infection, leaves showed yellowing and necrosis on adaxial surfaces and sparse mycelia growth was observed on the abaxial surface of older leaves. Later, thick white mycelial growth was observed on the lower side of young leaves (Figure 1). As the disease progressed, leaves dried and turned brown, then blackened, leading to 80–100 % loss in yield. One infected leaf was collected from each of three plants for further examination and pathogen identification. Microscopic observation revealed downy growth on the abaxial surface of leaves with numerous sporangia. The mycelium was hyaline, aseptate and branched, 5–15 μm in diameter. Sporangiophores were slender with monopodial branching at right angles and with a slight bulbous base. The sporangia were hyaline, smooth, globose to ellipsoidal with apical papilla and basal hilum on three sterigma, measuring 18–30 × 14–20 µm (Figure 2). Based on these characteristics, the pathogen was identified as Plasmopara sphagneticolae (Davis et al., 2020; Wang et al., 2021). To confirm the identity of the pathogen, total DNA was isolated from two of the samples (PSB-1 and PSB-2) using the CTAB method and the COX 2 region was amplified using primers Cox2F and Cox2R (Hudspeth et al., 2000). Analysis of the sequences using BLASTn showed the highest identity to P. sphagneticolae isolates BRIP61010 and BPI919166 (Genbank Accession Nos. KM085175 and MT292790, respectively). The consensus sequences were submitted to Genbank (OQ200475 and OQ200476). Phylogenetic analysis showed that the sequences of PSB-1 and PSB-2 clustered closely with isolates of P. sphagneticolae. Both P. sphagneticolae and its sister species P. halstedii cause downy mildew on many crops in the Asteraceae. Plasmopara sphagneticolae was first identified in Australia infecting Sphagenticola trilobata (McTaggart et al., 2015), and was then found on Lipochaeta integrifolia in Hawaii (Davis et al., 2020) and Taiwan (Wang et al., 2021). This is the first report of P. sphagneticolae in India and the first record of this pathogen causing downy mildew on bhringraj. The authors are grateful to the Director, Indian Institute of Horticultural Research, Bangalore. Financial assistance to K. Hima Bindu from NMPB, India (Project No; Z. 18017) is acknowledged.","PeriodicalId":36931,"journal":{"name":"New Disease Reports","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136054899","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}
N. Sagar, M. M. Jamadar, C. N. L. Reddy, B. R. Sayiprathap, M. Bharath, N. H. Shalini, S. B. Jagginavar, P. S. Pattar, C. R. Jahir Basha
Grape (Vitis vinifera) is an important fruit crop in India with about 3.5 million tonnes produced annually from an area of 111,000 ha. The Indian state of Karnataka is the major producer of grapes contributing about 25% of the national production. Downy mildew disease caused by Plasmopara viticola (Berk. & Curt.) is a threat to grape production throughout the world. Several fungicides have been used to manage downy mildew in grapevine, the most important being the quinone outside inhibitor stigmatellin binding type (QoSI) fungicide, ametoctradin, which has been used successfully in India for about a decade. However, in recent years’ farmers have noticed the failure of ametoctradin in managing downy mildew, and evolved resistance has been observed in France (Fontaine et al., 2019). In the present study, 41 downy mildew samples were collected from the major grapevine-growing districts of Karnataka state during 2022–23 and analysed for the presence of QoSI resistance. Sensitivity to QoSI fungicide was determined using a modified 24-well leaf-disc bioassay (Fungicide Resistance Action Committee, 2003). Healthy leaves were taken from the 6th node from the apex of a growing shoot of a downy mildew-susceptible grapevine cultivar (cv. Thomson Seedless) and 15 mm discs were cut from the leaves. The leaf discs were placed upside down in wells containing 1 mL of 0.5% water agar amended with 0, 100, 500, 1500, 2500 or 3000 µg mL−1 of either ametoctradin (300 g/l active ingredient) or dimethomorph (225 g/l active ingredient) (Zampro, BASF) as described by Sawant et al. (2016). Each treatment was repeated four times. Leaf disks were then inoculated with 10 µL of a suspension of P. viticola sporangia (50,000 sporangia mL−1) collected from a single lesion. Plates were incubated at 22°C with alternating periods of 12 hours light and dark. After six days, lesion area was measured and EC50 value was calculated by regression analysis of the per cent area of infection versus log10 fungicide concentration and resistance factor was also determined as described by Massi et al. (2021). The EC50 value of a sensitive isolate to the ametoctradin and dimethomorph mix was 2.36 µg/mL. The EC50 value of moderately resistant isolates ranged from 389 to 874 g/mL with RF (164-370), for resistant isolates the value ranged from 569 to 1126 µg/mL with RF (241-477) and for highly resistant isolates it ranged from 956 to 1423 µg/mL with RF (405-603). The BN-2 isolate from Babanagar, Vijayapur district had the largest EC50 value (1423 µg/mL). The resistance to QoSI fungicides in P. viticola developed due to a mutation in the cytochrome b (Pv-Cyt b) gene at the S34L site. This was detected using allele-specific primers 5′-ATTATTTTTATGGATTCGGTTT-3′ (forward) and 5′-ACCAACCGTTATTTACATCAC-3′ (reverse) as described by Fontaine et al. (2019). Total DNA was isolated from the isolates using a NucleoSpin Plant II kit as per the manufacturer's protocol (Macherey-Nagel, Germany) and the quality wa
葡萄(Vitis vinifera)是印度一种重要的水果作物,在11.1万公顷的土地上每年生产约350万吨葡萄。印度卡纳塔克邦是葡萄的主要产地,约占全国产量的25%。由葡萄浆原菌引起的霜霉病。& Curt.)是全球葡萄生产的一大威胁。几种杀菌剂已被用于防治葡萄霜霉病,其中最重要的是醌外抑制剂柱头孢素结合型(QoSI)杀菌剂ametoctradin,该杀菌剂在印度已成功使用约十年。然而,近年来农民已经注意到ametoctradin在管理霜霉病方面的失败,并且在法国观察到进化的抗性(Fontaine et al., 2019)。在本研究中,从卡纳塔克邦主要葡萄种植区收集了41份霜霉病样本,分析了其对QoSI抗性的存在。采用改良的24孔叶盘生物测定法测定对QoSI杀菌剂的敏感性(杀菌剂耐药性行动委员会,2003年)。从一个霜霉病易感葡萄品种(cv)的生长期顶端第6节取下健康叶片。从叶子上切下15毫米的圆盘。按照Sawant等人(2016)的描述,将叶盘倒置放置在含有1 mL 0.5%水琼脂的井中,分别用0、100、500、1500、2500或3000µg mL - 1的ametoctradin (300 g/l有效成分)或dimethomorph (225 g/l有效成分)(Zampro, BASF)进行修饰。每次治疗重复4次。然后在叶片上接种从单个病变中收集的10µL葡萄孢孢子囊悬液(50,000 mL−1)。培养皿在22℃下孵育,明暗交替孵育12小时。6天后,测量病变面积,通过对感染面积百分比与杀菌剂浓度log10的回归分析计算EC50值,并根据Massi et al.(2021)的描述确定抗性因子。该菌株对氨氯霉素和啶菊酯混合物的EC50值为2.36µg/mL。中等耐药菌株的EC50值为389 ~ 874 g/mL(164 ~ 370),耐药菌株的EC50值为569 ~ 1126µg/mL(241 ~ 477),高耐药菌株的EC50值为956 ~ 1423µg/mL(405 ~ 603)。来自Vijayapur地区Babanagar的BN-2分离物EC50值最高,为1423µg/mL。葡萄霉对QoSI杀菌剂产生抗性是由于细胞色素b (Pv-Cyt b)基因在S34L位点发生突变。根据Fontaine等人(2019)的描述,使用等位基因特异性引物5 ' - attattttttggattcggttt -3 '(正向)和5 ' - accaaccgttttttacatac -3 '(反向)进行检测。根据制造商的协议(Macherey-Nagel,德国),使用NucleoSpin Plant II试剂盒从分离物中分离总DNA,并使用Qubit®3.0荧光仪(Thermo Fisher Scientific,美国)评估质量。在所检测的41株菌株中,37株耐药菌株产生了预期大小的扩增子(152 bp),而4株敏感菌株没有产生扩增子。该扩增子的检测表明,Pv-Cyt b基因中的S34L氨基酸突变与对醌内外抑制剂(QoSI)(即ametoctradin)和其成分的商业产品的敏感性降低有关(Fontaine等,2019)。据我们所知,这是印度葡萄球菌首次出现QoSI (ametoctradin)耐药性。有趣的是,相关卵菌荔枝疫霉(Phytophthora litchii)也产生了对ametoctradin的抗性,这归因于PlCyt b (S33L和D228N)的变化(Gao et al., 2022);荔枝荔枝中的S33L与Plasmopara中的S34L同源(Oliver et al, 2023)。还需要进一步开展工作,监测白栎种群对QoSI杀菌剂的耐药性,并提醒种植者使用替代杀菌剂,以有效控制病害。
{"title":"First report of quinone outside inhibitor stigmatellin binding type (QoSI) resistance in <i>Plasmopara viticola</i> in India","authors":"N. Sagar, M. M. Jamadar, C. N. L. Reddy, B. R. Sayiprathap, M. Bharath, N. H. Shalini, S. B. Jagginavar, P. S. Pattar, C. R. Jahir Basha","doi":"10.1002/ndr2.12223","DOIUrl":"https://doi.org/10.1002/ndr2.12223","url":null,"abstract":"Grape (Vitis vinifera) is an important fruit crop in India with about 3.5 million tonnes produced annually from an area of 111,000 ha. The Indian state of Karnataka is the major producer of grapes contributing about 25% of the national production. Downy mildew disease caused by Plasmopara viticola (Berk. & Curt.) is a threat to grape production throughout the world. Several fungicides have been used to manage downy mildew in grapevine, the most important being the quinone outside inhibitor stigmatellin binding type (QoSI) fungicide, ametoctradin, which has been used successfully in India for about a decade. However, in recent years’ farmers have noticed the failure of ametoctradin in managing downy mildew, and evolved resistance has been observed in France (Fontaine et al., 2019). In the present study, 41 downy mildew samples were collected from the major grapevine-growing districts of Karnataka state during 2022–23 and analysed for the presence of QoSI resistance. Sensitivity to QoSI fungicide was determined using a modified 24-well leaf-disc bioassay (Fungicide Resistance Action Committee, 2003). Healthy leaves were taken from the 6th node from the apex of a growing shoot of a downy mildew-susceptible grapevine cultivar (cv. Thomson Seedless) and 15 mm discs were cut from the leaves. The leaf discs were placed upside down in wells containing 1 mL of 0.5% water agar amended with 0, 100, 500, 1500, 2500 or 3000 µg mL−1 of either ametoctradin (300 g/l active ingredient) or dimethomorph (225 g/l active ingredient) (Zampro, BASF) as described by Sawant et al. (2016). Each treatment was repeated four times. Leaf disks were then inoculated with 10 µL of a suspension of P. viticola sporangia (50,000 sporangia mL−1) collected from a single lesion. Plates were incubated at 22°C with alternating periods of 12 hours light and dark. After six days, lesion area was measured and EC50 value was calculated by regression analysis of the per cent area of infection versus log10 fungicide concentration and resistance factor was also determined as described by Massi et al. (2021). The EC50 value of a sensitive isolate to the ametoctradin and dimethomorph mix was 2.36 µg/mL. The EC50 value of moderately resistant isolates ranged from 389 to 874 g/mL with RF (164-370), for resistant isolates the value ranged from 569 to 1126 µg/mL with RF (241-477) and for highly resistant isolates it ranged from 956 to 1423 µg/mL with RF (405-603). The BN-2 isolate from Babanagar, Vijayapur district had the largest EC50 value (1423 µg/mL). The resistance to QoSI fungicides in P. viticola developed due to a mutation in the cytochrome b (Pv-Cyt b) gene at the S34L site. This was detected using allele-specific primers 5′-ATTATTTTTATGGATTCGGTTT-3′ (forward) and 5′-ACCAACCGTTATTTACATCAC-3′ (reverse) as described by Fontaine et al. (2019). Total DNA was isolated from the isolates using a NucleoSpin Plant II kit as per the manufacturer's protocol (Macherey-Nagel, Germany) and the quality wa","PeriodicalId":36931,"journal":{"name":"New Disease Reports","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136093471","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}
I. Mohd Anuar, S. A. Nusaibah, G. Vadamalai, A. S. Mokhtar, Z. Sapak
{"title":"First report of Pineapple mealybug wilt‐associated virus 1 and 3 associated with mealybug wilt of pineapple disease on pineapple in Malaysia","authors":"I. Mohd Anuar, S. A. Nusaibah, G. Vadamalai, A. S. Mokhtar, Z. Sapak","doi":"10.1002/ndr2.12231","DOIUrl":"https://doi.org/10.1002/ndr2.12231","url":null,"abstract":"","PeriodicalId":36931,"journal":{"name":"New Disease Reports","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139330258","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}