ORCID Profile
0000-0001-9778-2245
Current Organisations
Lincoln University
,
Murdoch University
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Publisher: Springer Science and Business Media LLC
Date: 03-11-2022
DOI: 10.1007/S00284-022-03068-0
Abstract: Grapevine trunk diseases (GTDs) are a significant problem for New Zealand viticulture. Endophytic actinobacteria are of interest as potential biocontrol agents due to their ability to inhibit plant pathogens and improve plant growth. However, no studies have investigated the ersity of actinobacteria associated with grapevines in New Zealand vineyards and their bioactivity. Actinobacteria ersity in different ‘Sauvignon blanc’ vine tissues from three vineyards (conventional and organic management, and different vine ages) was assessed using different methods and media. Forty-six endophytic actinobacteria were isolated, with more isolates recovered from roots ( n = 45) than leaves ( n = 1) and shoot internodes ( n = 0). More isolates were recovered from the organic ( n = 21) than conventional ( n = 8) vineyard, mature (25-year old n = 21) than young (2-year old n = 2) vines and using a tissue maceration technique ( n = 40). Actinomycete Isolation Agar, International Streptomyces Project 2, and Starch Casein media were effective for actinobacteria isolation. Most of the isolates recovered belonged to Streptomyces , with one isolate identified as Mycolicibacterium . Forty isolates were assessed for antifungal activity and plant growth-promoting (PGP) characteristics. Of these, 13 isolates had antifungal activity against test GTD pathogens ( Dactylonectria macrodidyma, Eutypa lata, Ilyonectria liriodendri, Neofusicoccum parvum , and N. luteum ) . Eighteen isolates exhibited more than one PGP trait 25siderophore production ( n = 25), phosphate solubilization ( n = 6), and indole acetic acid production ( n = 16). Two strains, Streptomyces sp. LUVPK-22 and Streptomyces sp. LUVPK-30, exhibited the best antifungal and PGP properties. This study revealed the ersity of culturable endophytic actinobacteria from grapevines in New Zealand vineyards and their biocontrol potential against GTD pathogens.
Publisher: Elsevier BV
Date: 02-2023
DOI: 10.1016/J.SCITOTENV.2022.159961
Abstract: The objectives of this study were to investigate the abundance and community composition of comammox Nitrospira under: (i) pasture-based dairy farms from different regions, and (ii) different land uses from the same region and soil type. The results clearly showed that comammox Nitrospira were most abundant (3.0 × 10
Publisher: Springer Science and Business Media LLC
Date: 10-05-2022
DOI: 10.1186/S12866-022-02520-2
Abstract: Grapevine trunk diseases (GTDs) are a threat to grape production worldwide, with a erse collection of fungal species implicated in disease onset. Due to the long-term and complex nature of GTDs, simultaneous detection of multiple microbial species can enhance understanding of disease development. We used DNA metabarcoding of ribosomal internal transcribed spacer 1 (ITS1) sequences, supported by specific PCR and microbial isolation, to establish the presence of trunk pathogens across 11 vineyards (11–26 years old) over three years in Marlborough, the largest wine producing region in New Zealand. Using a reference database of trunk pathogen sequences, species previously associated with GTD, such as Cadophora luteo-olivacea , Diplodia seriata, Diplodia mutila , Neofusicoccum australe, and Seimatosporium vitis , were identified as highly represented across the vineyard region. The well-known pathogens Phaeomoniella chlamydospora and Eutypa lata had especially high relative abundance across the dataset, with P. chlamydospora reads present between 22 and 84% (average 52%) across the vineyards. Screening of sequences against broader, publicly available databases revealed further fungal species within families and orders known to contain pathogens, many of which appeared to be endemic to New Zealand. The presence of several wood-rotting basidiomycetes (mostly Hymenochaetales) was detected for the first time in the Marlborough vineyard region, notably, the native Inonotus nothofagii which was present at 1–2% relative abundance in two vineyards.
Publisher: Elsevier BV
Date: 04-2022
DOI: 10.1016/J.MIMET.2022.106455
Abstract: The purpose of developing this high throughput assay was to determine whether there was evidence of pH adaptation in strains of rhizobia which nodulate subterranean clover (SC) and white clover (WC), and whether this was related to the pH of the soil of origin. pH is a first-order factor influencing the niche preferences of soil microorganisms and has been convincingly shown to be a key driver of soil bacterial communities. Naturalised strains of Rhizobium spp. that are pH-adapted may have the potential to better compete and/or persist in acidic or alkaline soils compared with introduced commercial strains. Three pilot studies were conducted to design the optimised bioassay. This bioassay tested the effect of pH-amended yeast mannitol broth (seven pH values from pH 4.5-9.0), across three time points, on the in vitro growth of 299 Rhizobium strains isolated from the nodules of SC and WC. The media pH where strains demonstrated fastest growth was related to the pH of the soil that strains were isolated from. However, the correlation between media pH and soil pH was strongly influenced by the growth of strains from alkaline soils (alkaline adaptation), especially in strains isolated from SC nodules.
Publisher: MDPI AG
Date: 16-02-2017
DOI: 10.3390/IJMS18020428
Publisher: Oxford University Press (OUP)
Date: 15-03-2021
DOI: 10.1111/JAM.15050
No related grants have been discovered for Anish Shah.