scholarly journals Resistance of New Zealand Provenance Leptospermum scoparium, Kunzea robusta, Kunzea linearis, and Metrosideros excelsa to Austropuccinia psidii

Plant Disease ◽  
2020 ◽  
Vol 104 (6) ◽  
pp. 1771-1780 ◽  
Author(s):  
Grant R. Smith ◽  
Beccy J. Ganley ◽  
David Chagné ◽  
Jayanthi Nadarajan ◽  
Ranjith N. Pathirana ◽  
...  
Keyword(s):  
New Zealand ◽  
Resistance Mechanisms ◽  
Rust Disease ◽  
Disease Symptoms ◽  
Stem Infection ◽  
Stem Resistance ◽  
New Finding ◽  
Austropuccinia Psidii ◽  
Assessment Scales ◽  
Leptospermum Scoparium

Resistance to the pandemic strain of Austropuccinia psidii was identified in New Zealand provenance Leptospermum scoparium, Kunzea robusta, and K. linearis plants. Only 1 Metrosideros excelsa-resistant plant was found (of the 570 tested) and no resistant plants of either Lophomyrtus bullata or L. obcordata were found. Three types of resistance were identified in Leptospermum scoparium. The first two, a putative immune response and a hypersensitive response, are leaf resistance mechanisms found in other myrtaceous species while on the lateral and main stems a putative immune stem resistance was also observed. Both leaf and stem infection were found on K. robusta and K. linearis plants as well as branch tip dieback that developed on almost 50% of the plants. L. scoparium, K. robusta, and K. linearis are the first myrtaceous species where consistent infection of stems has been observed in artificial inoculation trials. This new finding and the first observation of significant branch tip dieback of plants of the two Kunzea spp. resulted in the development of two new myrtle rust disease severity assessment scales. Significant seed family and provenance effects were found in L. scoparium, K. robusta, and K. linearis: some families produced significantly more plants with leaf, stem, and (in Kunzea spp.) branch tip dieback resistance, and provenances provided different percentages of resistant families and plants. The distribution of the disease symptoms on plants from the same seed family, and between plants from different seed families, suggested that the leaf, stem, and branch tip dieback resistances were the result of independent disease resistance mechanisms.

How an Indigenous community responded to the incursion and spread of myrtle rust (Austropuccinia psidii) that threatens culturally significant plant species – a case study from New Zealand

2019 ◽  
Vol 25 (4) ◽  
pp. 348 ◽  
Author(s):  
Amanda Black ◽  
Melanie Mark-Shadbolt ◽  
Gary Garner ◽  
Jenny Green ◽  
Tame Malcolm ◽  
...  
Keyword(s):  
Social Media ◽  
New Zealand ◽  
Indigenous Community ◽  
Rust Disease ◽  
Pests And Diseases ◽  
Historical Significance ◽  
Myrtle Rust ◽  
Plant Nursery ◽  
Austropuccinia Psidii

The incursion of the myrtle rust disease (Austropuccinia psidii) was officially confirmed on 3 May 2017 at a plant nursery located in Kerikeri, North Island, New Zealand. Since then the presence of myrtle rust has now been located throughout New Zealand, with additional outbreaks in Taranaki, Waikato and Bay of Plenty. It has been detected on a range of Myrtaceaea species including ramarama (Lophomyrtus bullata), pōhutukawa (Metrosideros excelsa), Monkey apple (Syzygium smithii), mānuka (Leptospermum scoparium), and Eucalyptus spp. (E. botryoides). Many of these species are iconic to the Indigenous Māori and have historical significance, being taonga (treasures). Since the incursions, Te Tira Whakamātaki (National Māori Biosecurity Network), have been informing Māori communities throughout New Zealand about the potential impacts of myrtle rust via a series of regional meetings (hui), email and social media that have included brief reports and recommendations. Feedback from these meetings and social media has strongly highlighted the desires of Māori communities to be active participants in decision-making and response plans for the management of myrtle rust as well as other pests and diseases. In this paper, we describe the journey of an Indigenous community approach to a modern biosecurity incursion.

scholarly journals Leptospermum repo (Myrtaceae), a new species from northern Aotearoa / New Zealand peat bog habitats, segregated from Leptospermum scoparium s. l.

2021 ◽  
Vol 78 (4) ◽  
pp. 247-265
Author(s):  
Peter J. de Lange ◽  
◽  
Luzie M.H. Schmid ◽  
Keyword(s):  
New Species ◽  
New Zealand ◽  
Vascular Plant ◽  
Peat Bogs ◽  
Peat Bog ◽  
Rust Disease ◽  
Potential Threat ◽  
Aotearoa New Zealand ◽  
Northern Portion ◽  
Austropuccinia Psidii

Leptospermum repo de Lange & L.M.H.Schmid sp. nov. (Myrtaceae) is segregated from L. scoparium J.R.Forst. & G.Forst. (sensu lato). The new species is endemic to the peat bogs of the Waikato, Bay of Plenty, and adjacent eastern ranges of the northern portion of Te Ika a Maui / North Island, Aotearoa / New Zealand. The new species belongs to the northern Te Ika a Maui / North Island clade of L. scoparium s. l., from whose other members it is morphologically distinguished by its gracile, spindly, open-branched growth habit; widely divergent, longer, linear, linear-lanceolate (rarely filiform), shortly cuspidate leaves; flowers with white petals, stamens mostly with white filaments (very rarely tinged pink near base), and by the style and stigma which are usually green (very rarely pink). Leptospermum repo now occupies ca. 10% of its former peat bog habitat, where aside from a few protected peat bogs the species is still in decline through loss of its habitat. A more recent potential threat to L. repo is myrtle rust disease, caused by Austropuccinia psidii, an exotic rust first detected in Aotearoa / New Zealand in May 2017. This rust poses a serious threat to the Myrtaceae of Aotearoa / New Zealand, for which there is at present no known effective treatment to prevent the death of infected hosts. Therefore, due to the historic loss of habitat, a threat which is still ongoing, causing the decline of many L. repo populations; and the potential threat of Austropuccinia psidii to this species, the listing proposed for the species (as Leptospermum aff. scoparium (c) (AK191319; "Waikato peat bog") by the New Zealand Indigenous Vascular Plant Threat Listing Panel of "Threatened / Nationally Critical DP, De" is here upheld.

The origin of methylglyoxal in New Zealand manuka (Leptospermum scoparium) honey

2009 ◽  
Vol 344 (8) ◽  
pp. 1050-1053 ◽  
Author(s):  
Christopher J. Adams ◽  
Merilyn Manley-Harris ◽  
Peter C. Molan
Keyword(s):  
New Zealand ◽  
Leptospermum Scoparium

scholarly journals New Zealand indigenous Myrtaceae in foreign botanic gardens: testing the sentinel plant concept for biosecurity risk assessment

2021 ◽  
Vol 74 (1) ◽  
pp. 1-9
Author(s):  
Kirsty S.H. Boyd-Wilson ◽  
M. Virginia Marroni ◽  
Mark R. McNeill ◽  
David A.J. Teulon
Keyword(s):  
Risk Assessment ◽  
New Zealand ◽  
Invasive Alien Species ◽  
The United States ◽  
Botanic Gardens ◽  
Indigenous Plants ◽  
Myrtle Rust ◽  
Potential Pest ◽  
Austropuccinia Psidii ◽  
Plant Biosecurity

The use of sentinel or expatriate plants is a growing concept for risk assessment in plant biosecurity. This approach involves ascertaining the presence and impact of pests and pathogens on plants foreign to a given location but planted in international botanic gardens or arboreta. The data obtained provide information on the potential pest status of these pests and pathogens, as invasive alien species (IAS), to plant species in their native or indigenous range. Assessment of the biosecurity threat from IAS for indigenous plants not found within the geographic distribution of these pests and pathogens is challenging, however, as they may be relatively taxonomically distinct from plants found in the distribution of the IAS and can be in different climates and environments. We examine the sentinel/expatriate concept in relation to risk assessment for myrtle rust (Austropuccinia psidii) on New Zealand Myrtaceae on these plants found in botanic gardens and arboreta outside New Zealand. Between September 2017 and September 2018, we identified and then contacted 65 botanic gardens or arboreta that putatively had New Zealand Myrtaceae and were within the known distribution of myrtle rust. We asked for information on the presence of New Zealand Myrtaceae species in their collections and whether these plants were infected by myrtle rust. Sixteen gardens/arboreta responded; most were in Australia or the United States. Only one of these gardens provided information that was useful for biosecurity risk assessment for myrtle rust on New Zealand Myrtaceae. The results are discussed in the context of plant biosecurity risk assessment and the broader sentinel/expatriate plant concept.

scholarly journals Safety in New Zealand weed biocontrol a nationwide pathogen survey for impacts on nontarget plants

2009 ◽  
Vol 62 ◽  
pp. 41-49 ◽  
Author(s):  
N.W. Waipara ◽  
J. Barton ◽  
L.A. Smith ◽  
H.M. Harman ◽  
C.J. Winks ◽  
...  
Keyword(s):  
New Zealand ◽  
Host Range ◽  
Plant Pathogens ◽  
Research Programme ◽  
Disease Symptoms ◽  
Weed Biocontrol ◽  
Disease Surveys ◽  
Rubus Species ◽  
Disease Damage ◽  
Range Testing

The accuracy of host range testing in weed biocontrol programmes using plant pathogens has been questioned prompting a research programme into the field safety record of pathogens used for weed biocontrol in New Zealand Nationwide disease surveys were conducted from 20002009 and focused on species closely related to target weeds and therefore potentially most at risk of attack These surveys identified pathogens associated with any disease symptoms observed on nontarget hosts Disease damage attributable to biocontrol agents was observed on two nontarget plants Pustules of the blackberry rust Phragmidium violaceum were found on the endemic Rubus species R cissoides (bush lawyer tataramoa) at one location This result was predicted from host range safety tests conducted prior to its arrival in New Zealand No nontarget damage was observed in the remaining case studies confirming to date that all biocontrol pathogens are highly host specific to their target weeds

scholarly journals A Model and Image Based Investigation of X. fastidiosa Within Host Dynamics  

2021 ◽  
Author(s):  
Nancy Walker ◽  
Kathryn Rankin ◽  
Siul Ruiz ◽  
Daniel McKay Fletcher ◽  
Katherine Williams ◽  
...  
Keyword(s):  
Research Effort ◽  
Vascular Plant ◽  
Extracellular Polysaccharide ◽  
Resistance Mechanisms ◽  
Vascular Networks ◽  
Disease Symptoms ◽  
Physical Description ◽  
Olive Cultivars ◽  
Olive Quick Decline Syndrome ◽  
Biofilm Development

<p>Photosynthesis relies on the transport of water and sugars from roots to leaves facilitated by two key tissues: xylem and phloem. Blockages in the xylem/phloem, either by structures formed by the pathogen itself or those formed by the plant as a defence mechanism, disrupt the soil-plant-atmosphere continuum and cause many vascular plant disease symptoms.<em> Xylella fastidiosa </em>(<em>X. fastidiosa</em>) is a bacterium that colonises internal plant vascular networks causing pathogenic effects on several commercially important crops, including those associated with the olive quick decline syndrome causing devastating olive decline in Apulia, Southern Italy.<em> </em>Despite a growing research effort since the recent detection of <em>X. fastidiosa</em> in Europe, the exact processes leading to <em>X. fastidiosa</em> disease symptoms are not fully understood due to difficulties in observing internal plant structures.</p> <p>Our goal is to utilise models to elucidate fundamental processes that lead to olive quick decline syndrome. We are developing a mathematical model describing within-host biofilm development that predicts water-stresses that ultimately inhibit plant functionality. Our approach is centred on the assumption that the biofilm structure is determined by the arrangement of extracellular polysaccharide (EPS) molecules, and as such, our model contains a polymer-physical description of <em>X. fastidiosa</em> biofilm formation dynamics. We used our model, requiring minimal empirical assumptions, to replicate biofilm aggregation observed by microfluidics. We have also produced X-ray Computed Tomography (XCT) images of vascular networks in both resistant and susceptible olive cultivars. We are using these images to test whether susceptibility is correlated with morphological differences that might influence fluid flow through the plant. This work improves the understanding of possible cultivar resistance mechanisms to aid informed breeding and orchard management, and model simulations will provide insights for understanding xylem blockages and their relation to observed symptom severity.</p>

The phylogenomics of diversification on an island: applying anchored hybrid enrichment to New Zealand Leptospermum scoparium (Myrtaceae)

2019 ◽  
Vol 191 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Matt H Buys ◽  
Richard C Winkworth ◽  
Peter J de Lange ◽  
Peter G Wilson ◽  
Nora Mitchell ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
New Zealand ◽  
Sequence Data ◽  
Large Data ◽  
Data Matrix ◽  
Data Set ◽  
Important Species ◽  
Anchored Hybrid Enrichment ◽  
Data Signal ◽  
Leptospermum Scoparium

Abstract Leptospermum scoparium (Myrtaceae) is a morphologically highly variable species found in mainland Australia, Tasmania and New Zealand. For example, in New Zealand up to six morphologically distinct varieties of this species have been described, although only two (var. scoparium and var. incanum) are now formally recognized. In the present study we provide a first examination of genetic diversity in this culturally and commercially important species with the aim of gaining insights into its origins and evolution. We used anchored hybrid enrichment to acquire sequence data from 485 orthologous low-copy nuclear loci for 27 New Zealand and three Australian accessions of L. scoparium and representatives of several other Leptospermum spp. The final concatenated data matrix contained 421 687 nucleotide positions of which 55 102 were potentially informative. Despite the relative large data set, our analyses suggest that a combination of low and incompatible data signal limits the resolution of relationships among New Zealand populations of L. scoparium. Nevertheless, our analyses are consistent with genetic diversity being geographically structured, with three groups of L. scoparium recovered. We discuss the evolutionary and taxonomic implications of our findings.

scholarly journals VI.—Notes on the Graptolite-bearing Rocks of New Zealand

1909 ◽  
Vol 6 (2) ◽  
pp. 74-75
Author(s):  
E. Douglass Isaacson
Keyword(s):  
New Zealand ◽  
Land Surface ◽  
Western Coast ◽  
Forest Trees ◽  
The West ◽  
North West ◽  
Stunted Growth ◽  
Extreme North ◽  
North And South ◽  
Leptospermum Scoparium

The series of beds containing graptolites in New Zealand occur in the Whakamarama district, which is situated in almost the extreme north-west of the South Island. They consist of intercalated bands of quartzite and carbonaceous argillites, with a north and south strike and dipping at a low angle to the west. As a result of the natural erosion of the land surface taking place more rapidly in the slaty layers than in the harder quartzites, the ridges and stream valleys exhibit a noticeable parallelism, those streams which enter the sea on the western coast usually taking a very sharp bend to the west, and with a somewhat gorgy channel to the sea. The valleys are for the most part densely clothed with forest trees, while the ridges of quartzite are barren, with the exception of a stunted growth of manuka (Leptospermum scoparium and L. ericoides), and in places a covering of peat to a depth of a few inches.

Isolation of maltol glucoside from the floral nectar of New Zealand mānuka (Leptospermum scoparium)

2015 ◽  
Vol 174 ◽  
pp. 306-309 ◽  
Author(s):  
Christopher J. Adams ◽  
Megan N.C. Grainger ◽  
Merilyn Manley-Harris
Keyword(s):  
New Zealand ◽  
Floral Nectar ◽  
Leptospermum Scoparium
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