Pub Date : 2019-07-28DOI: 10.30843/NZPP.2019.72.335
E. Veronesi, O. Olaniyan, S. Wratten, M. Davidson, C. Thompson
The tomato/potato psyllid (TPP), Bactericera cockerelli (Hemiptera, Triozidae), is an adventive psyllid in New Zealand that is a major pest of solanaceous crops and a serious threat to growers in the glasshouse industry. Worldwide, evaluation of potential biological control (BC) agents is normally conducted using single species and this is the case with some potential BC agents for TPP. However, the idea that multiple species can act synergistically remains largely untested so that is the aim of the current work, which is funded by Tomatoes New Zealand. The introduced parasitoid Tamarixia triozae is a BC agent of TPP that attacks mainly late instars. It lives for just 1 day when provided with water but can live up to 11 days (and consume more pests) when nectar in the flowers of buckwheat (Fagopyrum esculentum) is provided. In addition, another potential BC agent, the mirid bug Engytatus nicotianae, prefers young nymphal instars, while the ladybird Cleobora mellyi is voracious and consumes all instars. We are testing combinations of these species to understand the potential for synergies between and within trophic levels for better biological control.
{"title":"Better biological control in glasshouses: synergies between biological control agents from different guilds and floral resources","authors":"E. Veronesi, O. Olaniyan, S. Wratten, M. Davidson, C. Thompson","doi":"10.30843/NZPP.2019.72.335","DOIUrl":"https://doi.org/10.30843/NZPP.2019.72.335","url":null,"abstract":"The tomato/potato psyllid (TPP), Bactericera cockerelli (Hemiptera, Triozidae), is an adventive psyllid in New Zealand that is a major pest of solanaceous crops and a serious threat to growers in the glasshouse industry. Worldwide, evaluation of potential biological control (BC) agents is normally conducted using single species and this is the case with some potential BC agents for TPP. However, the idea that multiple species can act synergistically remains largely untested so that is the aim of the current work, which is funded by Tomatoes New Zealand. The introduced parasitoid Tamarixia triozae is a BC agent of TPP that attacks mainly late instars. It lives for just 1 day when provided with water but can live up to 11 days (and consume more pests) when nectar in the flowers of buckwheat (Fagopyrum esculentum) is provided. In addition, another potential BC agent, the mirid bug Engytatus nicotianae, prefers young nymphal instars, while the ladybird Cleobora mellyi is voracious and consumes all instars. We are testing combinations of these species to understand the potential for synergies between and within trophic levels for better biological control.","PeriodicalId":19180,"journal":{"name":"New Zealand Plant Protection","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82650083","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 : 2019-07-28DOI: 10.30843/NZPP.2019.72.324
Hau’ofa Siasau, R. Kant
Plutella xylostella is a major pest of crucifier crops in Samoa and other Pacific islands. This pest has developed resistance to most insecticides available in the island nations so the objective of this study was to examine potential biological control options for P. xylostella in Samoa. Existing parasitism of P. xylostella on Chinese cabbage (Brassica rapa subspp.) was investigated at a farm in Alesia and at the USP farm in Alafua, and established populations of Cotesia vestalis were found at both locations. Plutella xylostella larvae turn light yellow and show sluggish behaviour after parasitism, and they could be easily differentiated from unparasitised ones. Developing C. vestalis larvae emerge from their hosts and spin white cocoon around their body. After 5–6 days, a single adult emerges from the C. vestalis cocoon. The average parasitism rate between April 2015 and March 2016 was 10–18% but was significantly higher at the USP farm than the Alesia farm. This result could be because no insecticides were applied to the crops at USP. Parasitism was highest between June and August when the lowest average daily temperatures occur.
{"title":"Parasitism of diamondback moth Plutella xylostella by the solitary parasitoid wasp Cotesia vestalis in Samoa","authors":"Hau’ofa Siasau, R. Kant","doi":"10.30843/NZPP.2019.72.324","DOIUrl":"https://doi.org/10.30843/NZPP.2019.72.324","url":null,"abstract":"Plutella xylostella is a major pest of crucifier crops in Samoa and other Pacific islands. This pest has developed resistance to most insecticides available in the island nations so the objective of this study was to examine potential biological control options for P. xylostella in Samoa. Existing parasitism of P. xylostella on Chinese cabbage (Brassica rapa subspp.) was investigated at a farm in Alesia and at the USP farm in Alafua, and established populations of Cotesia vestalis were found at both locations. Plutella xylostella larvae turn light yellow and show sluggish behaviour after parasitism, and they could be easily differentiated from unparasitised ones. Developing C. vestalis larvae emerge from their hosts and spin white cocoon around their body. After 5–6 days, a single adult emerges from the C. vestalis cocoon. The average parasitism rate between April 2015 and March 2016 was 10–18% but was significantly higher at the USP farm than the Alesia farm. This result could be because no insecticides were applied to the crops at USP. Parasitism was highest between June and August when the lowest average daily temperatures occur.","PeriodicalId":19180,"journal":{"name":"New Zealand Plant Protection","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88190402","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 : 2019-07-28DOI: 10.30843/NZPP.2019.72.320
S. Visnovsky, R. Taylor, D. Teulon
Xylella fastidiosa (Xf), a xylem-limited bacterium native to the Americas, has a devastating impact on many crops internationally. In California, Xf causes over USD 100 million in yearly losses to the grape industry and infects an estimated 200 million citrus trees in Brazil. More recently, Xf killed around one million olive trees on the Italian peninsula of Salento. Xylella fastidiosa is not known to be present in New Zealand. The glassy-winged sharpshooter (Homalodisca vitripennis), an important vector of Xf in California, is also not present in New Zealand. However, the meadow spittle bug (Philaenus spumarius), an important vector of Xf in Italy, is present. Many economically important horticultural, viticultural, agricultural, amenity and indigenous/native plant species, including taonga, are likely to be susceptible to Xf. Aspects of our research on Xf to understand the impact, reduce the likelihood of entry into New Zealand and/or minimising its impact in New Zealand will be presented. The research listed on the poster spans risk assessment, diagnostics, surveillance and biological control but could certainly be increased across the biosecurity continuum given the magnitude of the threat from Xf to New Zealand’s valuable plant systems.
{"title":"Current and planned research for managing the risk of Xylella fastidiosa to New Zealand","authors":"S. Visnovsky, R. Taylor, D. Teulon","doi":"10.30843/NZPP.2019.72.320","DOIUrl":"https://doi.org/10.30843/NZPP.2019.72.320","url":null,"abstract":"Xylella fastidiosa (Xf), a xylem-limited bacterium native to the Americas, has a devastating impact on many crops internationally. In California, Xf causes over USD 100 million in yearly losses to the grape industry and infects an estimated 200 million citrus trees in Brazil. More recently, Xf killed around one million olive trees on the Italian peninsula of Salento. Xylella fastidiosa is not known to be present in New Zealand. The glassy-winged sharpshooter (Homalodisca vitripennis), an important vector of Xf in California, is also not present in New Zealand. However, the meadow spittle bug (Philaenus spumarius), an important vector of Xf in Italy, is present. Many economically important horticultural, viticultural, agricultural, amenity and indigenous/native plant species, including taonga, are likely to be susceptible to Xf. Aspects of our research on Xf to understand the impact, reduce the likelihood of entry into New Zealand and/or minimising its impact in New Zealand will be presented. The research listed on the poster spans risk assessment, diagnostics, surveillance and biological control but could certainly be increased across the biosecurity continuum given the magnitude of the threat from Xf to New Zealand’s valuable plant systems.","PeriodicalId":19180,"journal":{"name":"New Zealand Plant Protection","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79437344","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 : 2019-07-28DOI: 10.30843/NZPP.2019.72.321
K. Hofer, M. Toome‐Heller, B. Alexander
A project aiming to enhance biosecurity and market access in the Pacific was launched by NZ Aid in 2016. The project intends to benefit the economies of New Zealand’s Pacific neighbours by improving their biosecurity systems which, in turn, would help to protect New Zealand’s borders. Under the current project, the MPI’s Plant Health and Environment Laboratory (PHEL) is accountable for delivering insect pest and disease diagnostic training in the Pacific and developing diagnostic tools. The PHEL Mycology and Bacteriology team has delivered a number of plant pathology training sessions in New Zealand, Cook Islands and Fiji. The main focus of the pathology module was to provide the Biosecurity Authority of Fiji (BAF) Plant Health Laboratory staff with skills and tools to conduct plant disease diagnostics at their facility. This included a full laboratory refurbishment and new molecular setup. As a result, the BAF team has become efficient with isolating and identifying plant pathogens using a combination of morphology and DNA-based approaches. They are now able to provide fast and sensitive testing for high impact diseases at the border or in future incursions. In addition to laboratory staff training, a number of quarantine officers were trained to enable them to recognise diseased plant material during import and export fresh produce inspections.
{"title":"Enhancing plant disease diagnostics in the Pacific","authors":"K. Hofer, M. Toome‐Heller, B. Alexander","doi":"10.30843/NZPP.2019.72.321","DOIUrl":"https://doi.org/10.30843/NZPP.2019.72.321","url":null,"abstract":"A project aiming to enhance biosecurity and market access in the Pacific was launched by NZ Aid in 2016. The project intends to benefit the economies of New Zealand’s Pacific neighbours by improving their biosecurity systems which, in turn, would help to protect New Zealand’s borders. Under the current project, the MPI’s Plant Health and Environment Laboratory (PHEL) is accountable for delivering insect pest and disease diagnostic training in the Pacific and developing diagnostic tools. The PHEL Mycology and Bacteriology team has delivered a number of plant pathology training sessions in New Zealand, Cook Islands and Fiji. The main focus of the pathology module was to provide the Biosecurity Authority of Fiji (BAF) Plant Health Laboratory staff with skills and tools to conduct plant disease diagnostics at their facility. This included a full laboratory refurbishment and new molecular setup. As a result, the BAF team has become efficient with isolating and identifying plant pathogens using a combination of morphology and DNA-based approaches. They are now able to provide fast and sensitive testing for high impact diseases at the border or in future incursions. In addition to laboratory staff training, a number of quarantine officers were trained to enable them to recognise diseased plant material during import and export fresh produce inspections.","PeriodicalId":19180,"journal":{"name":"New Zealand Plant Protection","volume":"92 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73265882","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 : 2019-07-28DOI: 10.30843/NZPP.2019.72.326
D. Teulon, J. Kean, K. Armstrong
Fruit flies (Family Tephritidae), in particular the Queensland fruit fly (Bactrocera tryoni; QFF), areone of the biggest biosecurity risks for New Zealand horticulture. New Zealand has one of the bestscience-based biosecurity systems in the world, based on years of experience and sound research. Theintroduction of fruit flies to New Zealand is now well managed in commercial fruit imports, but the riskis rising from growing trade and travel and, in the case of QFF, climatic adaptation and spread to moresouthern localities. Smarter solutions are continually needed to manage this increasing risk, and to dealwith such pests when they arrive. We present a brief summary of current and anticipated research aimedat reducing the likelihood of entry into New Zealand and/or minimising the impact for the fruit flyspecies of greatest threat to New Zealand. Research spans risk assessment, pathway risk management,diagnostics, surveillance and eradication.
{"title":"Current and planned research for managing the fruit fly threat to New Zealand","authors":"D. Teulon, J. Kean, K. Armstrong","doi":"10.30843/NZPP.2019.72.326","DOIUrl":"https://doi.org/10.30843/NZPP.2019.72.326","url":null,"abstract":"Fruit flies (Family Tephritidae), in particular the Queensland fruit fly (Bactrocera tryoni; QFF), areone of the biggest biosecurity risks for New Zealand horticulture. New Zealand has one of the bestscience-based biosecurity systems in the world, based on years of experience and sound research. Theintroduction of fruit flies to New Zealand is now well managed in commercial fruit imports, but the riskis rising from growing trade and travel and, in the case of QFF, climatic adaptation and spread to moresouthern localities. Smarter solutions are continually needed to manage this increasing risk, and to dealwith such pests when they arrive. We present a brief summary of current and anticipated research aimedat reducing the likelihood of entry into New Zealand and/or minimising the impact for the fruit flyspecies of greatest threat to New Zealand. Research spans risk assessment, pathway risk management,diagnostics, surveillance and eradication.","PeriodicalId":19180,"journal":{"name":"New Zealand Plant Protection","volume":"30 20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81483944","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 : 2019-07-28DOI: 10.30843/NZPP.2019.72.307
I. Pushparajah, Dan Jones, K. Everett
A virulent strain of Pseudomonas syringae pv. actinidiae (Psa) is a major pathogen for New Zealand’s $3B kiwifruit (Actinidia spp.) industry, and was first identified from a Te Puke orchard on 5 November 2010. Psa was first found on the Kerikeri research orchard (KRO) of Plant & Food Research on 19 September 2014. The samples for this study were collected from the same orchard on 7 December 2012 and 25 November 2014, i.e. before and after the Psa incursion. Polymerase chain reaction (PCR) was conducted on total genomic DNA from four leaf discs of 15 individual vines sampled from two kiwifruit cv. ‘Hort16A’ orchard blocks at KRO, using modified PCR primers complementary to bacterial 16S ribosomal DNA and the fungal inter-transcribed spacer (ITS) region. The microbiota present before and after the Psa incursion were investigated by Illumina MiSeq™ next-generation sequencing to produce 2 × 300 bp pair end reads, followed by metabarcoding analysis using QIIME2 software. Populations of fungi from the Basidiomycete orders Filobasidiales, Sporidiobolales, Tremellales and Leucosporidiales, and genera of bacteria with known biological control activity, such as Erwinia, Pantoea, Methylobacterium, Sphingomonas and Paenibacillus, increased in the presence of Psa.
{"title":"Next-generation DNA sequencing shows a microbiota shift after an incursion of Pseudomonas syringae pv. actinidiae (Psa) on a single kiwifruit orchard","authors":"I. Pushparajah, Dan Jones, K. Everett","doi":"10.30843/NZPP.2019.72.307","DOIUrl":"https://doi.org/10.30843/NZPP.2019.72.307","url":null,"abstract":"A virulent strain of Pseudomonas syringae pv. actinidiae (Psa) is a major pathogen for New Zealand’s $3B kiwifruit (Actinidia spp.) industry, and was first identified from a Te Puke orchard on 5 November 2010. Psa was first found on the Kerikeri research orchard (KRO) of Plant & Food Research on 19 September 2014. The samples for this study were collected from the same orchard on 7 December 2012 and 25 November 2014, i.e. before and after the Psa incursion. Polymerase chain reaction (PCR) was conducted on total genomic DNA from four leaf discs of 15 individual vines sampled from two kiwifruit cv. ‘Hort16A’ orchard blocks at KRO, using modified PCR primers complementary to bacterial 16S ribosomal DNA and the fungal inter-transcribed spacer (ITS) region. The microbiota present before and after the Psa incursion were investigated by Illumina MiSeq™ next-generation sequencing to produce 2 × 300 bp pair end reads, followed by metabarcoding analysis using QIIME2 software. Populations of fungi from the Basidiomycete orders Filobasidiales, Sporidiobolales, Tremellales and Leucosporidiales, and genera of bacteria with known biological control activity, such as Erwinia, Pantoea, Methylobacterium, Sphingomonas and Paenibacillus, increased in the presence of Psa.","PeriodicalId":19180,"journal":{"name":"New Zealand Plant Protection","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81954912","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 : 2019-07-28DOI: 10.30843/NZPP.2019.72.327
R. Taylor, M. Toome‐Heller, W. Ho, B. Alexander
The Mycology and Bacteriology team of the Ministry for Primary Industries’ Plant Health and Environment Laboratory is responsible for the identification and verification of all suspected exotic, new, and emerging pathogens affecting plants and the environment in New Zealand. We work in an applied diagnostic environment where results can have significant implications for biosecurity. Sample submissions often result in detection of new to New Zealand fungi and bacteria on plants for which information on fungal and bacterial associations is generally sparse. The complexity of testing required is quite varied with samples being submitted from post entry quarantine (looking for a known pathogen using specific tests), border or surveillance (unknown pathogens requiring multiple tests), or a biosecurity response (scaling up to test large numbers, identification resolution required to strain level). Applied test methods depend largely on the sample type and consist of morphological identification, biochemical testing, pathogenicity testing, serological and molecular techniques, including high throughput sequencing. A profile of our diagnostic work and the most commonly detected taxa and host associations are presented.
{"title":"An insight into biosecurity plant-disease diagnostics at MPI","authors":"R. Taylor, M. Toome‐Heller, W. Ho, B. Alexander","doi":"10.30843/NZPP.2019.72.327","DOIUrl":"https://doi.org/10.30843/NZPP.2019.72.327","url":null,"abstract":"The Mycology and Bacteriology team of the Ministry for Primary Industries’ Plant Health and Environment Laboratory is responsible for the identification and verification of all suspected exotic, new, and emerging pathogens affecting plants and the environment in New Zealand. We work in an applied diagnostic environment where results can have significant implications for biosecurity. Sample submissions often result in detection of new to New Zealand fungi and bacteria on plants for which information on fungal and bacterial associations is generally sparse. The complexity of testing required is quite varied with samples being submitted from post entry quarantine (looking for a known pathogen using specific tests), border or surveillance (unknown pathogens requiring multiple tests), or a biosecurity response (scaling up to test large numbers, identification resolution required to strain level). Applied test methods depend largely on the sample type and consist of morphological identification, biochemical testing, pathogenicity testing, serological and molecular techniques, including high throughput sequencing. A profile of our diagnostic work and the most commonly detected taxa and host associations are presented.","PeriodicalId":19180,"journal":{"name":"New Zealand Plant Protection","volume":"2016 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86601462","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 : 2019-07-28DOI: 10.30843/NZPP.2019.72.328
H. Lee, W. Ho, R. Thangavel, J. Baskarathevan, B. Alexander
Citrus canker, a serious bacterial disease affecting the citrus industry worldwide, is caused by Xanthomonas citri subsp. citri (Xcc) pathotypes A, A* and Aw, and to a lesser extent by X. fuscans subsp. aurantifolii (Xfa). The recent citrus canker outbreak in Australia has emphasised the need to re-evaluate the efficiency of molecular assays used for detecting citrus canker bacteria. Two published probe-based qPCR assays targeting the pth and lrp genes were tested for Xcc, whereas a SYBR Greenbased qPCR assay was tested for Xfa. The Xcc pth gene and Xfa qPCR assays were shown to be specific towards all pathotypes of Xcc and Xfa, respectively. The detection limit for both assays were 1 pg of genomic DNA or 103 CFU in bacteria-spiked leaf sample. The Xcc lrp gene qPCR assay was able to discriminate Xcc pathotypes with a detection limit of 1 ng of genomic DNA or 106 CFU in bacteriaspiked leaf sample, but this assay showed cross-reaction with Xfa. To allow rapid high-throughput detection of all Xcc pathotypes, a duplex probe-based qPCR assay was developed by incorporating COX primers as an internal control for plant DNA into the pth gene qPCR assay.
{"title":"Validation of qPCR assays for the detection of citrus canker","authors":"H. Lee, W. Ho, R. Thangavel, J. Baskarathevan, B. Alexander","doi":"10.30843/NZPP.2019.72.328","DOIUrl":"https://doi.org/10.30843/NZPP.2019.72.328","url":null,"abstract":"Citrus canker, a serious bacterial disease affecting the citrus industry worldwide, is caused by Xanthomonas citri subsp. citri (Xcc) pathotypes A, A* and Aw, and to a lesser extent by X. fuscans subsp. aurantifolii (Xfa). The recent citrus canker outbreak in Australia has emphasised the need to re-evaluate the efficiency of molecular assays used for detecting citrus canker bacteria. Two published probe-based qPCR assays targeting the pth and lrp genes were tested for Xcc, whereas a SYBR Greenbased qPCR assay was tested for Xfa. The Xcc pth gene and Xfa qPCR assays were shown to be specific towards all pathotypes of Xcc and Xfa, respectively. The detection limit for both assays were 1 pg of genomic DNA or 103 CFU in bacteria-spiked leaf sample. The Xcc lrp gene qPCR assay was able to discriminate Xcc pathotypes with a detection limit of 1 ng of genomic DNA or 106 CFU in bacteriaspiked leaf sample, but this assay showed cross-reaction with Xfa. To allow rapid high-throughput detection of all Xcc pathotypes, a duplex probe-based qPCR assay was developed by incorporating COX primers as an internal control for plant DNA into the pth gene qPCR assay.","PeriodicalId":19180,"journal":{"name":"New Zealand Plant Protection","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79628273","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 : 2019-07-28DOI: 10.30843/NZPP.2019.72.330
M. Horner, E. Carroll, J. Wilton, W. Barrett
Several Actinidia spp. genotypes exhibit crown gall-like symptoms in both roots and canes. Galls form on roots and pruning wounds of canes. Investigations were undertaken to determine if an Agrobacterium species was responsible for gall formation in the Actinidia spp. material. Macerated galls were plated onto King’s B and various selective Agrobacterium agars, e.g. 1A and Roy & Sasser media. Bacterial isolates were tested by PCR for the presence of tumour-inducing (Ti) plasmids. Isolates that tested positive for the Ti plasmid were subsequently tested for pathogenicity by inoculation onto cut carrot discs, Nicotiana glutinosa and Solanum lycopersicum, and assessed for gall formation. Bacterial isolates that tested positive by PCR for the Ti plasmid were an orange tan colour on selective medium 1A, and clear with a red centre on the Roy & Sasser medium. Galls formed on cut carrots, S. lycopersicum and N. glutinosa after inoculation of Ti-positive bacterial isolates. Initial results indicate that an Agrobacterium species is associated with the formation of galls in Actinidia seedlings. However, biochemical characterisation and confirmation of Koch’s postulates using Actinidia species are needed for verification of this result.
{"title":"Galling in Actinidia spp. seedlings","authors":"M. Horner, E. Carroll, J. Wilton, W. Barrett","doi":"10.30843/NZPP.2019.72.330","DOIUrl":"https://doi.org/10.30843/NZPP.2019.72.330","url":null,"abstract":"Several Actinidia spp. genotypes exhibit crown gall-like symptoms in both roots and canes. Galls form on roots and pruning wounds of canes. Investigations were undertaken to determine if an Agrobacterium species was responsible for gall formation in the Actinidia spp. material. Macerated galls were plated onto King’s B and various selective Agrobacterium agars, e.g. 1A and Roy & Sasser media. Bacterial isolates were tested by PCR for the presence of tumour-inducing (Ti) plasmids. Isolates that tested positive for the Ti plasmid were subsequently tested for pathogenicity by inoculation onto cut carrot discs, Nicotiana glutinosa and Solanum lycopersicum, and assessed for gall formation. Bacterial isolates that tested positive by PCR for the Ti plasmid were an orange tan colour on selective medium 1A, and clear with a red centre on the Roy & Sasser medium. Galls formed on cut carrots, S. lycopersicum and N. glutinosa after inoculation of Ti-positive bacterial isolates. Initial results indicate that an Agrobacterium species is associated with the formation of galls in Actinidia seedlings. However, biochemical characterisation and confirmation of Koch’s postulates using Actinidia species are needed for verification of this result.","PeriodicalId":19180,"journal":{"name":"New Zealand Plant Protection","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75538318","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 : 2019-07-28DOI: 10.30843/NZPP.2019.72.329
B. M. Fisher, R. Scheper
Neonectria ditissima, the causal agent of European canker, can be present in symptomless scion wood. Sanitation treatments could minimise this risk to nursery trees. In this trial, six heat treatments and five chemical treatments were tested for their effectiveness in removing this pathogen from dormant ‘Royal Gala’ wood. In July 2018, 120 symptomless inoculated shoots (three inoculations/shoot) were harvested and stored at 1oC for 3 months. Bundles of five inoculated shoots (45 cm) were placed in the centre of 24 bundles, each consisting of 25 wood pieces. Heat-treated bundles were submerged in water (45oC for 45 min or 50oC for 15 min), or wrapped in moist cloth, vacuum sealed inside plastic then submerged for 3–6 h at the same temperatures. Chemical-treated bundles were submerged for 16 h at room temperature. Treatments were compared with untreated wood. After surface sterilising, isolation of N. ditissima from inoculated wounds was attempted on apple-sap amended water agar. All wounds from the untreated wood and from the chemical-treated wood yielded the pathogen. However, N. ditissima was not isolated from wounds that had been heat treated. Therefore, heat treatments that do not affect scion wood viability may prove an effective tool to remove European canker from nursery material.
{"title":"Heat treatments of dormant scion wood killed the European canker pathogen in planta, while chemical treatments did not","authors":"B. M. Fisher, R. Scheper","doi":"10.30843/NZPP.2019.72.329","DOIUrl":"https://doi.org/10.30843/NZPP.2019.72.329","url":null,"abstract":"Neonectria ditissima, the causal agent of European canker, can be present in symptomless scion wood. Sanitation treatments could minimise this risk to nursery trees. In this trial, six heat treatments and five chemical treatments were tested for their effectiveness in removing this pathogen from dormant ‘Royal Gala’ wood. In July 2018, 120 symptomless inoculated shoots (three inoculations/shoot) were harvested and stored at 1oC for 3 months. Bundles of five inoculated shoots (45 cm) were placed in the centre of 24 bundles, each consisting of 25 wood pieces. Heat-treated bundles were submerged in water (45oC for 45 min or 50oC for 15 min), or wrapped in moist cloth, vacuum sealed inside plastic then submerged for 3–6 h at the same temperatures. Chemical-treated bundles were submerged for 16 h at room temperature. Treatments were compared with untreated wood. After surface sterilising, isolation of N. ditissima from inoculated wounds was attempted on apple-sap amended water agar. All wounds from the untreated wood and from the chemical-treated wood yielded the pathogen. However, N. ditissima was not isolated from wounds that had been heat treated. Therefore, heat treatments that do not affect scion wood viability may prove an effective tool to remove European canker from nursery material.","PeriodicalId":19180,"journal":{"name":"New Zealand Plant Protection","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87230896","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：