Several published polymerase chain reaction (PCR) primers to identify Pseudomonas syringae pv. actinidiae , the causal organism of bacterial canker kiwifruit, were found not be specific. Two new sets PCR primers, PsaF1/R2 and PsaF3/R4, designed complementary a portion 16S–23S rDNA intertranscribed spacer (ITS) regions. These amplified DNA fragment from strains P. but 56 bacteria six genera 17 species, except for strain tea pathogen, theae . When tested against extracted further 20 Japan,...

Plant pathogen zoospores play a vital role in the transmission of several significant plant diseases, with their early detection being important for effective management. Current methods involve labour-intensive specimen collection and laboratory testing, lacking real-time feedback capabilities. Methods that can be deployed field remotely addressed are required. In this study, we have developed an innovative zoospore-sensing device by combining microfluidic sampling system cytometer...

Microbial ecology is challenging because of practical problems associated with detecting and quantifying populations Bacteria yeasts are not easily identified using conventional methods such as dilution plating biochemical tests Those lack sensitivity extremely timeconsuming cannot account for unculturable organisms New DNAbased technology microarrays offers solutions to those However identification microorganisms DNA methodology becoming increasingly complicated due the variation revealed...

Avocado scab was recorded as present in New Zealand international databases on the basis of one isolate (ICMP 10613) identified by morphological features Sphaceloma perseae. However, sequence analysis rDNA internal transcribed spacer (ITS) region showed that this dissimilar to ITS other species, and S. By phylogenetic analysis, ICMP 10613 a species Phaeosphaeria. To identify perseae reliably quickly, specific polymerase chain reaction (PCR) primers were developed tested. These PCR detected...

Various combinations of heat time and relative humidity (RH) were tested for their ability to kill Pseudomonas syringae pv actinidiae (Psa) the cause kiwifruit canker on freshly harvested anthers artificially contaminated with this bacterium Pollen viability Psa survival after treatment Although short durations at high temperatures RH did these treatments also lethal pollen When was reduced before lost increased but enhanced The most promising 35C a 50 or less which not affected even 20 h...

A method was developed to inoculate and establish infection of detached apple fruit with the bull’s eye rot pathogen, Phlyctema vagabunda (syn: Neofabraea alba), without wounding. Mycelial cultures P. did not produce conidia on commonly used potato dextrose agar, or several other tested media. Growth corn meal agar resulted in highest conidial yield, maximum production achieved after 5 days. These were placed water these spores for at least days establishment infections. Reliable 66—100%...

Bitter rot is an apple fruit disease most commonly caused in New Zealand by the fungus Colletotrichum acutatum The timing of fungicide applications to manage this was investigated during two seasons Fungicides applied October (carbendazim) or November and December (tolyfluanid captan mancozeb) reduced incidence rots expressing on trees orchard (halfstrength copper oxychloride Bacillus subtilis QST 713 tolyfluanid) January February postharvest regularly throughout season field but not...

A kiwifruit orchard that had tested positive for virulent Pseudomonas syringae pv actinidiae (PsaV) ca 2 km from the incursion detected in November 2010 was sampled on 13 December 2011 when weather overcast with some showers Surfaces people (hands soles of footwear clothing) vehicles (tyres seats floors steering wheels accelerators brakes and gear levers) cleaned tools (shovels tip squeezers various handles drill bit) rabbit feet were rubbed sterile cotton wool medical swabs After incubation...

Copper is the only fungicide currently registered for use on avocado orchards controlling fruit rots that are expressed postharvest Two additional fungicides performed well in previous tests were evaluated as spray applications to 12 four each of three major growing regions New Zealand (North Kaitaia Whangarei and Bay Plenty) Pyraclostrobin/boscalid fluazinam at least effective copper suitable alternatives Fluazinam should be applied winter because combination with additive di1pmethene it...

Populations of Pseudomonas syringae pv actinidiae (Psa) on vines sprayed with a biological control agent (Bacstar; Bacillus amyloliquefaciens D747; Ba) and untreated were monitored using qPCR Leaf discs taken from in February 2014 3 months after the final three spray applications Bacstar October November 2013 An aliquot leaf washings bacterial saline (BS) was spread to potato dextrose agar Petri plates numbers colonies Ba counted DNA extracted remaining BS quantity Psa determined recovered...

Bull’s eye rot, caused by Phlyctema vagabunda , is an important postharvest rot of apples. A combination laboratory and field trials were conducted to examine the relationship between infection status apple lenticels. Fruit hydrated then inoculated, climatic factors compared with inoculations natural infections in field. In it was shown that increased lenticel density size led more infections. Hydration distended diameter, dehydration contracted strong wind run, leaf wetness temperature be...

Abstract Bull’s eye rot is a postharvest storage disease of apples. Until now the cause this in New Zealand was not clear. A survey 6880 apples from five regions over two seasons conducted. Neofabraea malicorticis and N. perennans were found. One hundred seventy-nine isolates identified as Phlyctema vagabunda by specific polymerase chain reactions and/or sequencing β-tubulin gene region followed phylogenetic analysis. Two kienholzii . Previous records presence based on spore morphology...

ISHS V International Symposium on Postharvest Pathology: From Consumer to Laboratory-Sustainable Approaches Managing Pathogens Semi-commercial hot water treatments control apple bull's eye rot (Neofabraea alba)

Current methods for producing conidia of Neofabraea alba the fungal cause Bulls eye rot apple are laborious and timeconsuming A minimum 6 weeks is required Mycelial cultures N did not produce on commonly used potato dextrose agar therefore several other media were tested Growth corn meal resulted in a high conidial yield (ca 106 conidia/ml) after 57 days growth Published research reports method to inoculate apples with this pathogen without wounding but it requires specialised equipment...

The thermal death point was determined in vitro for three isolates of Pseudomonas syringae pv actinidiae (Psa) A bacterial suspension treated by placing an Eppendorf tube then floating a water bath at seven temperatures from 263 to 60C At each temperature aliquot removed after 5 15 35 75 155 315 and 635 min placed onto Kings medium B (KMB) Petri plates spread with sterilised bent glass rod were 25C 24 h colonies counted There isolate replicates per timetemperature combination no difference...

Ten compounds were evaluated for their effects on the efficacy of bacterial biological control agent (BCA) HR42 against avocado postharvest rot fungus Colletotrichum acutatum The 10 (chitin Dglucose glycol chitosan Lserine Laspartic acid calcium chloride carbonate potassium ammonium molybdate and sodium carbonate) at four different concentrations (1 100 1000 mM) tested separately fungal growth all stimulated suppressed mycelial C BCA these then in combination detached fruit ability to...

Previous laboratory and field tests have indicated that calcium shows promise for control of bitter rots on apple caused by Colletotrichum acutatum This year a replicated fungicide spray trial was conducted commercial orchard in Rukuhia Waikato block planted with Royal Gala apples Chemicals were applied at 1014 day intervals from October to February Calcium chloride applications as effective fungicides fruit both high low rates but damaged leaves is already some cultivars not often It...

Pseudomonas syringae pv actinidiae (Psa) is a bacterium whose virulent form (PsaV) causes severe infections of kiwifruit particularly Actinidia chinensis Hort16A Lenticels on canes function as pores allowing gaseous exchange The lenticellular structure penetrates through the periderm potentially bacterial entry and subsequent cortex infection Bacteria have been observed inside directly below lenticels from ca 3yearold woody tissue field To investigate this pathway further three wood ages...

A prototype database has been developed to provide an uptodate New Zealandspecific resource for use by risk assessors An updated list of biosecurity plant fungal pathogens compiled apples grapes kiwifruit barley wheat and potato crops Based on analysis the literature most important factors assessments pathogen incursions are rusts proximity Zealand disease source other fungi presence in country Pathway (including wind pattern modelling rust incursions) is also component assessment For both...

Neofabraea actinidiae can occasionally cause post-harvest rot in kiwifruit. Quantitative polymerase chain reaction (qPCR) analysis represents a feasible and accurate option for identifying quantifying this but is limited because qPCR results do not differentiate live dead conidia. Propidium monoazide (PMA) photoreactive dye that penetrates into the damaged cell-wall membranes of conidia binding to DNA thus suppressing its amplification by qPCR. A commercial kit containing PMA was trialled...