scholarly journals Description of an Australian endemic species of Trioza (Hemiptera: Triozidae) pest of the endemic tea tree, Melaleuca alternifolia (Myrtaceae)

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257031
Author(s):  
Francesco Martoni ◽  
Mark J. Blacket

Psyllids, also known as jumping plant lice, are phloem feeding Hemiptera that often show a strict species-specific relationship with their host plants. When psyllid-plant associations involve economically important crops, this may lead to the recognition of a psyllid species as an agricultural or horticultural pest. The Australian endemic tea tree, Melaleuca alternifolia (Maiden & Betche) Cheel., has been used for more than a century to extract essential oils and, long before that, as a traditional medicine by Indigenous Australian people. Recently, a triozid species has been found to damage the new growth of tea trees both in Queensland and New South Wales, raising interest around this previously undocumented pest. Furthermore, adults of the same species were also collected from Citrus plantations, leading to potential false-positive records of the exotic pest Trioza erytreae (Del Guercio 1918), the African Citrus psyllid. Here we describe for the first time Trioza melaleucae Martoni sp. nov. providing information on its distribution, host plant associations and phylogenetic relationships to other Trioza species. This work enables both morphological and molecular identification of this new species, allowing it to be recognized and distinguished for the first time from exotic pests as well as other Australian native psyllids. Furthermore, the haplotype network analysis presented here suggests a close relationship between Trioza melaleucae and the other Myrtaceae-feeding Trioza spp. from Australia, New Zealand, and Taiwan.

1992 ◽  
Vol 40 (3) ◽  
pp. 365 ◽  
Author(s):  
PA Butcher ◽  
JC Bell ◽  
GF Moran

Melaleuca alternifolia (Maiden & Betche) Cheel is harvested from natural stands and plantations for production of Australian tea-tree oil. Genetic variation was examined and outcrossing rates estimated to provide baseline information for breeding and selection programs. The overall genetic diversity (HT = 0.186) is comparable to other regionally distributed Australian tree species. There was a general trend for more isolated populations to have less genetic variation than populations from the centre of the species distribution. The level of differentiation among populations was low (12%), associated with a high outcrossing rate (93%) and high levels of gene flow. Geographic separation of Queensland and New South Wales populations corresponds with genetic distance measures.


1981 ◽  
Vol 21 (111) ◽  
pp. 439 ◽  
Author(s):  
BEJ Small

A plant spacing experiment with the tea tree oil species, Melaleuca alternifolia was carried out at Castle Hill, New South Wales, from 1970 to 1979. The study compared the response to three within-row spacings and measured the effects of seasons over seven harvests. The planting patterns tested were 1.22 x 1.22, 0.61 and 0.305 m. For all years there was an average increase in leaf and oil yield of 93% (2.9 l/ha and 46 l/ha, respectively) in the highest population (26 908 trees/ha) compared with the lowest (6727 trees/ha). Large differences in growth rate and oil yield occurred between years. I conclude that M. alternifolia is amenable to cultivation for tea tree oil production, plant spacing is an important factor in its management and optimum population exceeds 27 000 trees/ha.


2000 ◽  
Vol 48 (3) ◽  
pp. 367 ◽  
Author(s):  
M. Rossetto ◽  
F. C. L. Harriss ◽  
A. Mclauchlan ◽  
R. J. Henry ◽  
P. R. Baverstock ◽  
...  

This study investigated the interspecific amplification of 35 microsatellite loci developed for M. alternifolia across seven other species within the Myrtaceae. All the primers used gave successful amplification of loci in at least one of the species tested. The level of success varied between species; 88.6% of primers gave amplification products for Melaleuca spp., 74.3% for Callistemon salignus, 45.7% for Eucalyptus spp. and 25.7% for Backhousia citriodora. Sequencing of a number of amplification products confirmed the presence of microsatellites in those loci. This study shows that the development of species-specific microsatellite libraries might not always be necessary. Cross-species amplification could enable the application of microsatellite technology to studies with limited resources, a feature characteristic of conservation projects.


1984 ◽  
Vol 35 (4) ◽  
pp. 427 ◽  
Author(s):  
SJ Rowland

The status of bream, from estuaries near Narooma on the south coast of New South Wales, which display morphological characteristics intermediate to those distinguishing the species A. australis and A. butcheri was investigated. The two species were separated electrophoretically at a malate dehydrogenase locus (Mdh-1) where they are fixed for alternative alleles, and by a significant difference in allele frequency at the lactate dehydrogenase locus Ldh-A. Because four individual bream, which displayed intermediate morphometric characteristics, have inherited both species-specific Mdh-1 alleles and are heterozygous at the Ldh-A locus, their status as hybrids is determined. The presence of three bream with allelic characteristics of A. australis at the Mdh-1 locus but allelic characteristics of A. butcheri at the Ldh-A locus is evidence for the presence of later generation or backcross hybrids. No evidence of introgression was found. The reproduction of A. australis and A. butcheri is temporally and spatially isolated under normal circumstances but in some landlocked, coastal lakes there is a breakdown of these isolating mechanisms. Because A. australis and A. butcheri differ morphometrically and ecologically over their sampled ranges, and only appear to hybridize in the unusual environmental conditions of closed lakes, it is suggested that their specific status be retained. Using electrophoretic data, a high level of genic similarity (I = 0.91) was found to exist between the two species. This, together with the close relationship indicated by the production of fertile F1 hybrids, suggests a recent speciation.


Aquaculture ◽  
2021 ◽  
pp. 736954
Author(s):  
Tamires R. dos Reis ◽  
Matheus D. Baldissera ◽  
Carine F. Souza ◽  
Bernardo Baldisserotto ◽  
Julia Corá Segat ◽  
...  

2021 ◽  
Vol 53 (1) ◽  
pp. 95-101
Author(s):  
Gintaras Kantvilas

AbstractThe lichen genus Lecanactis Körb. in Tasmania comprises six species: L. abietina (Ach.) Körb., which is widespread and pan-temperate; L. latispora Egea & Torrente and L. neozelandica Egea & Torrente, both shared with New Zealand and with the former recorded here from the Auckland Islands for the first time; L. mollis (Stirt.) Frisch & Ertz, shared with Victoria and New Zealand; L. aff. dilleniana (Ach.) Körb., a European species recorded provisionally for Tasmania on the basis of several sterile collections; L. scopulicola Kantvilas, which is described here as new to science and apparently a Tasmanian endemic. This new taxon occurs in rocky underhangs and is characterized by a thick, leprose thallus containing schizopeltic acid, and 3-septate ascospores, 19–30 × 4.5–6 μm. Short descriptions and a discussion of distribution and ecology are given for all species. A key for all 11 Australian species of the genus is provided, including L. subfarinosa (C. Knight) Hellb. and L. tibelliana Egea & Torrente, which are recorded for Australia for the first time, and L. platygraphoides (Müll.Arg.) Zahlbr., a first record for New South Wales. Lecanactis spermatospora Egea & Torrente and L. sulphurea Egea & Torrente are also included.


2017 ◽  
Vol 65 (4) ◽  
pp. 327 ◽  
Author(s):  
Saskia Grootemaat ◽  
Ian J. Wright ◽  
Peter M. van Bodegom ◽  
Johannes H. C. Cornelissen ◽  
Veronica Shaw

Bark shedding is a remarkable feature of Australian trees, yet relatively little is known about interspecific differences in bark decomposability and flammability, or what chemical or physical traits drive variation in these properties. We measured the decomposition rate and flammability (ignitibility, sustainability and combustibility) of bark from 10 common forest tree species, and quantified correlations with potentially important traits. We compared our findings to those for leaf litter, asking whether the same traits drive flammability and decomposition in different tissues, and whether process rates are correlated across tissue types. Considerable variation in bark decomposability and flammability was found both within and across species. Bark decomposed more slowly than leaves, but in both tissues lignin concentration was a key driver. Bark took longer to ignite than leaves, and had longer mass-specific flame durations. Variation in flammability parameters was driven by different traits in the different tissues. Decomposability and flammability were each unrelated, when comparing between the different tissue types. For example, species with fast-decomposing leaves did not necessarily have fast-decomposing bark. For the first time, we show how patterns of variation in decomposability and flammability of bark diverge across multiple species. By taking species-specific bark traits into consideration there is potential to make better estimates of wildfire risks and carbon loss dynamics. This can lead to better informed management decisions for Australian forests, and eucalypt plantations, worldwide.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 622
Author(s):  
Alexandra Ciorîță ◽  
Septimiu Cassian Tripon ◽  
Ioan Gabriel Mircea ◽  
Dorina Podar ◽  
Lucian Barbu-Tudoran ◽  
...  

Morphological and anatomical traits of the Vinca leaf were examined using microscopy techniques. Outdoor Vinca minor and V. herbacea plants and greenhouse cultivated V. major and V. major var. variegata plants had interspecific variations. All Vinca species leaves are hypostomatic. However, except for V. minor leaf, few stomata were also present on the upper epidermis. V. minor leaf had the highest stomatal index and V. major had the lowest, while the distribution of trichomes on the upper epidermis was species-specific. Differentiated palisade and spongy parenchyma tissues were present in all Vinca species’ leaves. However, V. minor and V. herbacea leaves had a more organized anatomical aspect, compared to V. major and V. major var. variegata leaves. Additionally, as a novelty, the cellular to intercellular space ratio of the Vinca leaf’s mesophyll was revealed herein with the help of computational analysis. Lipid droplets of different sizes and aspects were localized in the spongy parenchyma cells. Ultrastructural characteristics of the cuticle and its epicuticular waxes were described for the first time. Moreover, thick layers of cutin seemed to be characteristic of the outdoor plants only. This could be an adaptation to the unpredictable environmental conditions, but nevertheless, it might influence the chemical composition of plants.


1966 ◽  
Vol 3 (5) ◽  
pp. 401-411 ◽  
Author(s):  
A. A. Ressang ◽  
F. C. Stam ◽  
G. F. De Boer

Zwoegerziekte is a disease in Dutch sheep which morphologically closely resembles an Icelandic sheep disease, Maedi2. Chronic lung affection and emaciation are the principal symptoms of both diseases. Visna is another chronic condition in Icelandic sheep affecting mainly the C.N.S. A virus has been isolated from sheep affected with Maedi or Visna and a close relationship in properties has been found between both viruses. In two Dutch sheep autopsied in the final stage of Zwoegerziekte, lesions were present in the C.N.S., which histologically resembled those in Visna. Another sheep slaughtered at the municipal abattoir, with lung lesions characteristic for the terminal stage of Zwoegerziekte, exhibited early cerebral lesions resembling Visna. The lesions in the C.N.S. of these three sheep were meningitis and severe encephalomyelitis of the glial type affecting the white matter. Secondary demyelination was striking. Though Zwoegerziekte has been known for several decades in the Netherlands, the accompanying C.N.S. lesions are described for the first time.


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