Zealand Plants Research Articles

New Zealand Plant Protection Society / Zespri Kiwifruit Scholarship

Production of Actinidia chinensis (kiwifruit) is a billion- dollar industry in New Zealand that is threatened by various pests and diseases. Armoured scale insects, leafroller insects and a disease caused by the bacterium Pseudomonas syringae pv. actinidiae (Psa) all cause economic loss to the kiwifruit industry because of the damage they inflict and the market access restrictions imposed if their presence is detected. Examining the available kiwifruit germplasm pool for resistance to the armoured scale insect (Hemiberlesia lataniae) was identified as
 a promising first step towards introgression of resistance into future kiwifruit cultivars. To integrate resistance alleles into current and future breeding programmes efficiently, robust markers linked to resistance genes need to be identified.
 Casey Flay, recipient of the NZPPS/Zespri Kiwifruit Scholarship, is a PhD student at Massey University. In the first year of his PhD, Casey studied H. lataniae scale resistance markers in a small family of A. chinensis var. chinensis from breeding populations at the New Zealand Institute of Plant & Food Research. Markers were identified for this population that were associated with phenotype and were validated in a related population. To test these markers in a diverse background, four families made from a cross of wild-sourced material was phenotyped. All the seedlings resulting from crossing resistant parents with a tolerant parents were resistant to H. lataniae. However, further work is required to backcross resistant progeny with susceptible parents before marker information can be associated with phenotype. Ongoing work includes studying H. lataniae resistance as well as resistance to the brownheaded leafroller (Ctenopseustis obliquana) in a large kiwifruit population which is segregating for resistance to both H. lataniae and C. obliquana. Loci responsible for each type of resistance will be identified and a detailed quantitative trait locus (QTL) map generated. This process will allow markers to be developed to target these QTLs, enabling them to be robust tools for resistance breeding. Casey will also study the effects of Psa on the kiwifruit germplasm collection at Plant & Food Research. Selection mapping will be used to assess alleles that are removed from the germplasm population as a consequence of Psa infection. Results of this work will provide information on the sections of the kiwifruit genome that confer tolerance or susceptibility to Psa, enabling breeders to enhance breeding
 for resistance to Psa.
 Breeding for resistance to biotic threats that are currently targeted by chemical sprays is a reasonable move toward a healthier, cheaper and more environmentally friendly form of food production. This will benefit organic producers and conventional producers alike by reducing market access issues, decreasing the need for pest control, and decreasing the real and perceived risks associated with spray residues, resulting in increased market appeal and economic returns.
 This one-off NZPPS/Zespri Kiwifruit Scholarship was possible thanks to Zespri. It was funded by the proceeds of a symposium on Psa held in Palmerston North in 2016 run jointly by Zespri and the New Zealand Plant Protection Society.

New Zealand Plant Protection Medal 2016

This medal is awarded by the New Zealand Plant Protection Society to honour those who have made exceptional contributions to plantprotection in New Zealand in the widest sense. The medal is awarded for outstanding services to plant protection, whether through research,education, implementation or leadership. 
 In 2016, the New Zealand Plant Protection Medal was awarded to Dr Rob Beresford who is one of New Zealand’s most experienced and versatile plant pathologists. Rob started his career in science with an MSc Hons, 1st class, in Auckland in 1978 and was appointed to DSIR Plant Diseases Division at Lincoln in 1979. He was awarded a National Research Advisory Council Postgraduate Research Fellowship to undertake PhD studies at Long Ashton Research Station in the UK from1982 to 1985, returning to Lincoln in 1986. Those studies kicked off a long career in epidemiology and today Rob is New Zealand’s pre-eminent plant disease epidemiologist. For 30 years, Rob has been New Zealand’s strongest advocate for the use of weather-based disease prediction for developing practicaldisease control strategies, particularly to reduce the economic, environmental and market residue impacts of fungicide use. By understanding and modelling relationships between pathogen biology and ecology and weather, Rob has translated complex correlations between biological and physical factorsinto simple practical tools for growers to use for disease control. To date, these have included decision support tools for apple scab, downy mildew in onions, botrytis in grapes and more recently Psa in kiwifruit. He has also developed prediction models for climatic risk of invasive pathogens (potato wart disease and myrtle rust) and for the impacts of climate change on crop diseases. 
 Recognising the importance of climate and weather in affecting plant diseases, Rob has, for many years, championed a network of weather stations in the key horticultural districts throughout New Zealand to generate data for the decision-support tools. It has been a struggle to keep the network running against shortages of funding and the frequent need to re-assert the value of the network to New Zealand horticulture. Rob has built a team of equally committed colleagues who share this understanding and, through tenacity and persistence, have recently achieved an upgrade of the entire network to internet-based communication systems. It is through his close collaborations over many years with the software company HortPlus that his decision support tools have been delivered to the commercial arena. 
 Rob was a member of the New Zealand team that argued the case at the World Trade Organisation for the easing of restrictions on New Zealand apples entering Australia. Rob’s superior skills in interpreting climate data, in this case Australian data, in terms of pathogen survival, establishment and spread, and his clarity in presenting the results were instrumental in the success of that case in 2010.
 In parallel with Rob’s epidemiological strategy to reduce fungicide use is his interest in the threat of pathogens developing resistance to fungicides. Rob leads research to identify resistance threats to fungicides and also provides liaison between grower associations and agrochemical companies to design and implement robust resistance-management strategies. His focus on resistance started in 2005 when he published updated management strategies for all nine of the then available fungicide groups for the New Zealand Plant Protection Society (NZPPS). In 2007, he re-established the New Zealand Committee on Pesticide Resistance (NZCPR) (which had been in abeyance for 10 years) and chaired the committee’s work on fungicides, insecticides and herbicides from 2007 to 2012. He stepped aside to become NZCPR Science Advisor in 2012 so he could focus on resistance research. Following devastating disease outbreaks of apple scab (Venturia ineaqualis) in the pipfruit industry in 2009, Rob initiated a research programme with Pipfruit New Zealand that showed the cause of the outbreaks to be resistance to two groups of fungicides in use at the time. He has recently coordinated resistance strategy updates for botrytis affecting the wine industry, for summer fruit diseases and is currently leading a programme to monitor resistance of grape powdery mildew to key groups of fungicides. Rob was awarded the 2014 Plant & Food Research Chairman’s Award for his work on fungicide resistance.
 Rob is an effective communicator at all levels from heavy science to grower forums and is always willing to share his time, skills and knowledge. He has been involved with undergraduate lecturing for many years and has successfully supervised several PhDs.
 NZPP Medal recipients for the previous five years:2015: Gary Barker2014: -2013: Andrew Hodson2012: Margaret Dick2011: Jim Walker

New Zealand Plant Protection Society Research Scholarship

The necrotrophic fungus Ciborinia camelliae Kohn causes a disease known as camellia petal blight that has been disfiguring camellia flowers (Fig. 1) since it was first found in New Zealand in 1993. This blight has severally impacted the camellia seed oil industry, floriculture industry, and has been a great frustration to keen camellia growers over the last 25 years but no viable control methods for camellia petal blight have been discovered so far. The Camellia Memorial Trust has helped fund a research team at Massey University to study the interaction between
 camellia plants and this pathogen. Hannah McCarthy, recipient of the 2017/2018 New Zealand Plant Protection Society Research Scholarship, is part of this team. Ciborinia camellia is host and tissue specific, which restricts its infection capability to flowers of the Camellia genus. This disease spreads by ascospores, which after landing on a susceptible Camellia spp. bloom, germinate to grow hyphae and cause necrosis and death of the petal tissues. The flower then falls prematurely to the ground, where the fungus survives as hardened sclerotium until the next flowering season.
 Most plant pathogens utilise a range of proteins to promote infection using mechanisms that include the suppression of plant immunity, degradation of cell walls, or the manipulation of the host’s immunity to their own advantage. These proteins are known as ‘effectors’ and identification of these complex molecules has led to a better understanding of disease and new disease-control strategies for other plants. The aim of Hannah’s MSc research is to identify effectors in Ciborinia camelliae, and she has been focusing on a protein family that shares characteristics (such as high cysteine content and the size of protein sequences) with known effectors from other fungi. This protein family is called Ciborinia camelliae-like small secreted proteins (CCL-SSPs). There are 73 unique protein sequences in Ciborinia camelliae but of the ten tested for necrotic ability by recombinant expression and infiltration into camellia petals, none were found to induce cell death. However, a protein found in the closely related fungus Sclerotinia sclerotiorum, was found to induce very rapid cell death, which was visible just two hours after infiltration. This protein from Sclerotinia sclerotiorum has high sequence similarity to CCL- SSPs. To identify the function of this protein family, Hannah is performing region swaps between the S. sclerotiorum protein and a Ciborinia camelliae CCL-SSP. By the end of
 this project, the research team hopes to have: (a) identified the region of the S. sclerotiorum protein responsible for its necrotic activity; (b) compared this region with sequences of Ciborinia camelliae CCL-SSPs; and (c) deduced the likely function of this protein family, and its role in camellia petal blight.

New Zealand Plant Protection Medal 2017

This medal is awarded by the New Zealand Plant Protection Society to honour those who have made exceptional contributions to plant protection in New Zealand in the widest sense. The medal is awarded for outstanding services to plant protection, whether through research, education, implementation or leadership.
 In 2017, the New Zealand Plant Protection Medal was awarded Prof David Maxwell (Max) Suckling. In his 35+ years of research, Max has been pivotal in bringing odour-based technologies to New Zealand. In particular, his research on insect pheromones has enabled integrated pest management to be realised in this country. As a result, New Zealand plant-based industries can access premium overseas markets due to the low pest prevalence and low pesticide residue on primary produce. It has also reduced grower exposure to pesticides.
 The acknowledgement of his broad knowledge of risks and benefits that new organisms and substances can pose to New Zealand has been exemplified by his position of Chair of the Environmental Risk Management Authority Hazardous Substances and New Organisms Committee where he presided over decisions from determining which organisms are new to New Zealand through to whether the benefits of the release of new organisms outweighed the risks. His unique knowledge and ability to make sound judgements based on the evidence presented also led to two invitations back to the Environmental Protection Authority after he had finished as a special member on the Committee so that New Zealand could safely continue to assess the use of biological control agents.
 Since 2004, in his role as Science Group Leader of the Biosecurity group at The New Zealand Institute for Plant and Food Research Ltd (PFR), Max has been instrumental in developing tools to improve detection sensitivity and socially acceptable eradication options for new pests that threaten New Zealand, such as the Queensland fruit fly and the painted apple moth.
 Max has been a member of the New Zealand Plant Protection Society for many years and served as President from 1999 to 2001. He was nominated for the Medal because of the passion he has displayed towards developing and making available socially acceptable pest eradication and management tools in New Zealand. The work that he and the chemical ecology team he has built and led, has had a large impact in many sectors from horticulture to biosecurity.
 This use of socially acceptable tools for the productive sectors naturally led to Max’s involvement in the pest surveillance and eradication space. He led the Eradication and Response Theme in the Better Border Biosecurity collaboration for over ten years, co-ordinating research among Crown Research Institutes to achieve their goals and the goals of New Zealand’s biosecurity practitioners. He has gone beyond odour-based technologies and branched into sound, vision and sterile-insect technologies for managing pests, sticking with the social acceptance theme.
 Max is an innovative thinker, testing novel approaches for pest management, and can bring quite separate groups together to achieve a goal. For example, he combined an irradiator used to sterilise medical equipment and insect rearing to achieve a boutique insect-sterilisation programme against the painted apple moth. By pushing the envelope, he is seen as a world leader in his field of using socially acceptable tools, with numerous invitations as a keynote speaker at international meetings, which has allowed him to return to New Zealand with some of the latest scientific ideas.
 He has served on working groups of the sterile-insect technique for the joint division of the Food and Agriculture Organization/International Atomic Energy Agency. He was recently made a professor when he was made a joint appointment at PFR and the University of Auckland, and has supervised and co-supervised a number of PhD and MSc students.
 His outstanding collaboration and mentoring skills enable him to work across different fields, secure new knowledge and tools for novel pest-management approaches, bring together people from different organisations, and mentor ‘thinking-out-of-the-square’ scientists for the future.
 His desire to protect New Zealand’s flora, fauna and people, make him a worthy recipient of the New Zealand Plant Protection Medal.
 
 NZPP Medal recipients for the previous five years:
 2016: Rob Beresford
 2015: Gary Barker
 2014: -
 2013: Andrew Hodson
 2012: Margaret Dick

New Zealand plant growth trials in rapid bio-filtration media

Abstract Media used in rapid bio-filtration devices have hydraulic conductivity rates exceeding 2,500 mm/hr. Stormwater360 New Zealand has partnered with Contech Engineered Solutions (USA) to produce a rapid bio-filtration medium using locally available materials. Current bio-filtration guidance limits the hydraulic conductivity of media to less than 300 mm/hr to support plant growth. Using a short-term plant trial (3 months) and 4 ongoing plant trials (>11 months) plant growth was assessed. In total 99 plants were grown (26 different tree, shrub and grass species), of which 91 plants (92%) and 23 plant species (88%) successfully established and grew in the rapid filtration medium.

Gymnocoronis spilanthoides

Gymnocoronis spilanthoides

Taxonomic notes on the New Zealand flora: lectotypes in the fern families Athyriaceae and Cystopteridaceae

ABSTRACTThe fern families Athyriaceae and Cystopteridaceae have few representatives in New Zealand, the former having two indigenous and four naturalised species, and the latter just one native and one naturalised species. Three lectotypes are designated here for basionyms relevant to New Zealand—Allantodia tenera R.Br., A. umbrosum var. multifidum Dobbie and Cystopteris novae-zealandiae J.B.Armstr. We have found no type material for Asplenium umbrosum var. leumfolia Dobbie, and the type for this remains undesignated. Lectotypes need to be chosen for all names at specific and infraspecific rank, for which no holotypes were designated by the original author, in order to fix the application of the name concerned. We selected lectotypes from among the available syntypes using the following criteria: best match to the protologue; best specimen, showing the most number of diagnostic characters; specimen with the most precise locality information; specimen annotated or labelled by the author; and specimen in the principal herbarium of the author. This short communication is a contribution towards clarifying the taxonomic and nomenclatural status of New Zealand plants for the plant names database (Ngā Tipu Aotearoa) and the electronic Flora of New Zealand.

A preliminary conservation genetic study of Pittosporum obcordatum (Pittosporaceae), an endemic New Zealand species with a disjunct distribution

ABSTRACTPittosporum obcordatum (Pittosporaceae; heart-leaved kōhūhū) is an endemic New Zealand plant species that is classified as Threatened–Nationally Vulnerable. It has a disjunct distribution and is only known from relatively few and small populations. Using 10 Inter-Simple Sequence Repeat markers (ISSRs), we studied patterns of genetic diversity and genetic differentiation among eight out of the c. 14 populations of this species to inform its conservation management. Pittosporum obcordatum has low genetic diversity at the population level (uHe = 0.169) compared to other long-lived and outcrossing species, but genetic diversity is relatively high in comparison with several other threatened species. Spearman’s Rank Correlation Coefficients suggest significant positive correlations between population size and genetic diversity as measured by the percentage of polymorphic loci and uHe. Pittosporum obcordatum also shows relatively high levels of genetic differentiation among populations (AMOVA-derived , P < 0.001; all pairwise Φst values P < 0.05), indicating low genetic connectivity. Populations with relatively few plants are therefore prone to further reductions in genetic diversity through inbreeding and genetic drift. Of these, especially the Kaitaia, Owen Valley and Paengaroa populations are of conservation concern, because they contain private alleles, and therefore notably contribute to the genetic diversity of P. obcordatum.

Foreword

&#x0D; &#x0D; &#x0D; Welcome to Volume 70 of New Zealand Plant Protection (and its previous incarnations). As always, your Executive Committee and the Editor have worked hard to produce a volume we hope you will be proud of. We have a new Editor this year, Ruth Falshaw.&#x0D; &#x0D; &#x0D;

Manipulating rainfall to study symptom expression of &lt;i&gt;Botrytis cinerea&lt;/i&gt; infection in wine grapes

Manipulating rainfall to study symptom expression of &lt;i&gt;Botrytis cinerea&lt;/i&gt; infection in wine grapes

Taxonomic notes on the New Zealand flora: lectotypes in the fern family Aspleniaceae

ABSTRACTLectotypes are chosen for 10 basionyms relevant to New Zealand representatives of the fern family Aspleniaceae—Asplenium adiantoides var. minus Hook.f.; A. bulbiferum var. integra Kirk; A. durvillei Mett.; A. flabellifolium Cav.; A. flaccidum var. littoralis Dobbie; A. lucidum var. lyallii Hook.f.; A. lucidum var. paucifolium Hook.; A. ornatum Colenso; A. ramosum Dobbie; and Grammitis rutifolia R.Br. No type material has been found for Asplenium bulbiferum var. decomposita Kirk, A. bulbiferum var. pseudolucidum Kirk, A. obtusatum var. integrifolium Szyszyl., A. obtusatum var. pseudofalcatum Kirk and A. tremulum Hombr., and types for these remain undesignated. Lectotypes need to be chosen for all names at specific and subspecific rank, for which no holotypes were designated by the original author, in order to fix the application of the name concerned. This article is a contribution towards clarifying the taxonomic and nomenclatural status of New Zealand plants for the plant names database (Ngā Tipu Aotearoa) and the electronic Flora of New Zealand.

Polarized Light Microscopy: An Old Technique Casts New Light on Māori Textile Plants

Understanding the composition of an artefact has ramifications for advancing human history and behaviour knowledge, providing cultural information about trade, agricultural practices and adaptation to new environments. However, accurate plant identification from artefacts is problematic, since textile production, age, dirt and/or conservation treatments obscure morphological features, and specimen size and/or ethical considerations hamper modern analytical methods. This study tested the efficacy of polarized light microscopy (PLM) in the identification of New Zealand plant species commonly used in Māori textiles, and demonstrates that morphological and birefringent features observed using PLM have the potential to distinguish between- and within-plant genera.

Plant litter variability and soil N mobility

Laboratory incubation studies were used to investigate whether and how variability of different plant litters modifies the mobility of nitrogen in soil. Fallen plant foliage from native New Zealand plants of diverse fibre and nutrient content were selected, with C:N ratios ranging from 14 to 102. Different litters provided substantially different inputs of macro- and micronutrients to soil that affected the mobility of N. Both fibre content and C:N ratios were influential. A primary effect of litter addition to soil was modification of pH, largely attributable to calcium enrichment. Nitrate in soil was reduced by up to 85% following litter amendments. Incorporation of five native plant litters into soil significantly suppressed emissions of nitrous oxide. We interpret these findings in the context of plant residues from naturalistic planting on the borders of farm paddocks that may play a role in tightening the N cycle and restricting spillover of nitrogen pollutants to the wider environment.

Taxonomic notes on the New Zealand flora: lectotypes in the fern families Dennstaedtiaceae and Lindsaeaceae

ABSTRACTDennstaedtiaceae is a medium-sized family of ferns in New Zealand with 11 indigenous and two naturalised species. Lindsaeaceae is a small family with just three native species and one naturalised. Three lectotypes are chosen for basionyms relevant to New Zealand: Dicksonia davallioides R.Br., Lindsaea trilobata Colenso and Pteris vespertilionis Labill. Justification for the choice is provided in each case. This short communication is a contribution towards clarifying the taxonomic and nomenclatural status of New Zealand plants for the plant names database (Ngā Tipu Aotearoa) and the electronic Flora of New Zealand.

Asplenium decurrens Willd., an earlier name for A. northlandicum (Brownsey) Ogle

ABSTRACTThe nomenclatural history of the Asplenium obtusatum complex is reviewed. It is shown that when treated at subspecific rank, A. obtusatum subsp. northlandicum Brownsey, based on a New Zealand type, is the correct name for the octoploid taxon that occurs in both New Zealand and Australia. However, when raised to species rank there are two earlier validly published names, A. decurrens Willd. and A. sarmentosum Willd., based on Australian types, that take priority over Asplenium northlandicum (Brownsey) Ogle. Both names relate to the same taxon and were published simultaneously. The name A. decurrens is preferred because the holotype is based on a herbarium specimen, whereas the type of A. sarmentosum is an illustration. This short communication is a contribution towards clarifying the taxonomic and nomenclatural status of New Zealand plants for the plant names database (Ngā Tipu Aotearoa) and the electronic Flora of New Zealand.

Spinescence in the New Zealand flora: parallels with Australia

ABSTRACTPrickles, thorns and spines deter herbivory by large mammals. However, New Zealand lacked large mammals prehistorically and was instead home to large browsing birds. Perhaps as a result, very little research has been conducted on the production and function of prickles, thorns and spines in New Zealand plants. Here, I evaluate the ontogeny of spinescence in New Zealand and how it differs in taxa inhabiting offshore islands that never housed large browsing birds. I then review similar work on the ontogeny and biogeography of prickles, thorns and spines in Australia, where spinescence has been shown to deter herbivory by large vertebrates. Results show that a variety of New Zealand plant species deploy prickles, thorns and spines in similar ways to spinescent plants in Australia, suggesting that spinescence may have defended plants against large, avian herbivores. Results also highlight differences in the deployment of spinescence between the two floras, which may represent specific adaptations to avian browsers.

Research focus and authorship trends over 40 years of publications by New Zealand Plant Protection

In total 3053 contributions consisting of papers research notes and poster abstracts to the New Zealand Plant Protection Society from 1976 to 2015 were analysed for research and authorship trends The mean number of authors per paper per year increased from 18 to 43 over this period and institutional collaboration was increasingly common Proportionally there was a steady decrease in weed contributions and an increase in those featuring plant pathogens Control measures shifted from largely chemical solutions for single weed species to more integrated management programmes The number of papers on weed pest or disease biology incidence spread and impact were fairly constant over this period The scope of research widened considerably from a largely pastoral and arable focus to include environmental weeds and border biosecurity Topical research findings and review papers highlight the responsiveness of the plant protection research community to emerging novel issues

Taxonomic notes on the New Zealand flora: lectotypes in the fern family Thelypteridaceae

ABSTRACTThree lectotypes are chosen for basionyms relevant to New Zealand representatives of the fern family Thelypteridaceae: Aspidium novae-zeelandiae Ettingsh., Nephrodium propinquum R.Br. and Polypodium pennigerum var. giganteum Colenso. This article is a contribution towards clarifying the taxonomic and nomenclatural status of New Zealand plants for the plant names database (Ngā Tipu Aotearoa) and the electronic Flora of New Zealand.

Taxonomic notes on the New Zealand flora: lectotypes in the fern family Gleicheniaceae

Thirteen lectotypes are chosen for basionyms relevant to New Zealand representatives of the fern family Gleicheniaceae: Gleichenia alpina R.Br., Gleichenia ciliata Colenso, Gleichenia cunninghamii Hook., G. cunninghamii var. montanum Dobbie, Gleichenia dicarpa R.Br., Gleichenia flabellata R.Br., Gleichenia hecistophylla A.Cunn., Gleichenia hermannii R.Br., Gleichenia microphylla R.Br., Gleichenia patens Colenso, Gleichenia punctulata Colenso, Gleichenia semivestita Labill. and Gleichenia tenera R.Br. Four basionyms remain un-typified; three of these are varietal names for which the original materials have not been located, while the fourth, Gleichenia circinnata Sw., requires further examination. This article is a contribution towards clarifying the taxonomic and nomenclatural status of New Zealand plants for the plant names database (Ngā Tipu Aotearoa) and the electronic Flora of New Zealand.

Taxonomic notes on the New Zealand flora: lectotypes in the fern family Ophioglossaceae

Two lectotypes are chosen for basionyms relevant to New Zealand representatives of the fern family Ophioglossaceae—Ophioglossum vulgatum var. minimum Hook.f. and Ophioglossum minimum J.B.Armstr. This article is a contribution towards clarifying the taxonomic and nomenclatural status of New Zealand plants for the plant names database (Ngā Tipu Aotearoa) and the electronic Flora of New Zealand.