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Microsporidia are naturally occurring fungal-related parasites that can infect nearly all animal hosts, but their biocontrol potential of insect pests is routinely overlooked in agriculture and forestry. This research brings the first report describing the natural occurrence of a microsporidium causing disease in field-collected populations of the invasive eucalyptus snout beetle, Gonipterus platensis (Coleoptera: Curculionidae), a major destructive pest of eucalyptus plantations in Brazil. Adult beetles were collected during field surveys in commercial eucalyptus plantations in southern Brazil to be examined and dissected with typical symptoms to verify presence of microsporidian spores in haemolymph. From 14 plantations in different sites, the natural infection occurrence in these populations ranged from 0 to 65%, while a lab colony exhibited an infection incidence of 70%. Spore density in haemolymph of symptomatic insects averaged 2.1 (± 0.4) × 107 spores/beetle. Symptoms in infected adults were identified by an abnormal abdomen with malformation of the second pair of wings, impairing their flight activity. Electron transmission microscopy of the pathogen showed morphological features similar to species belonging to the genus Nosema or Vairimorpha. Phylogenetic analysis of the full-length small subunit ribosomal RNA gene suggests this pathogen's placement in the genus Vairimorpha, but with a sequence identity of ~ 94% with the nearest neighbours. The low level of sequence identity suggests this pathogen may represent a novel taxon in the genus and further requires whole genome sequencing for definitive taxonomic resolution. These findings provide insights on the natural occurrence of this novel pathogen of this invasive pest in Eucalyptus plantations in Brazil. Further studies are needed to determine potential of this microsporidium in the design of conservative or augmentative biological control programs for this invasive pest. [ABSTRACT FROM AUTHOR]

Ethiopia introduced Eucalyptus spp. in 1895. The most widely planted Eucalyptus species in Ethiopia include E. camaldulensis, E. globulus, E. grandis and E. saligna. Eucalyptus camaldulensis is widely planted between 1250 and 2800 m above sea level, where warm conditions prevail. In recent years, insect infestation has occurred in this species. The aim of this study was to identify the causative agent of this infestation in central Ethiopia. It was found that Glycaspis brimblecombei infested leaves of E. camaldulensis for the first time in our study areas. So far, no infestation of G. brimblecombei has occurred in other Eucalyptus species. In addition to the regular reconnaissance survey on existence and dissemination of G. brimblecombei infestation to other host Eucalyptus spp., the situation strongly urges the country to introduce and employ biological control agents against this threat to the plantations of E. camaldulensis in Ethiopia in order to avoid substantial economic losses to Eucalyptus growers in the country. [ABSTRACT FROM AUTHOR]

Seed predation can cause substantial seed losses and influence plant population dynamics, but the impact depends on the extent to which populations are limited by seed availability or favorable microsites for recruitment. Harvester ants are the dominant post-dispersal seed predators in Australia’s tropical savannas, and their abundance and foraging efficiency, as well as the availability of seed and microsites, are affected by fire history. We undertook a predator-exclusion experiment to examine the interactive effects of fire history (no fire compared with annual burning over 5 years) and seed predation by ants on seedling establishment of the dominant savanna tree, Eucalyptus miniata, in northern Australia. Despite its large seed size, the rate of removal (~ 20-60%) was similar or higher than typically reported for eucalypts, although it was lower than that recorded for the smaller seeds of the co-occurring E. tetrodonta. Seed predation rates were twice as high in annually burnt compared to unburnt sites, but there was no significant difference in the proportion of seedlings that emerged from the initial seed available. Seedling emergence in both regimes was low, representing < 7% of seed available after harvesting. About one-third of emergent seedlings were still alive during the middle of the following dry season. Our results indicate that seedling recruitment in E. miniata is limited by both seed supply and microsite availability. However, seed predation by ants reduces the likelihood of seedling establishment from low to virtually zero, which suggests that it plays a potentially important role in the population dynamics of savanna eucalypts. [ABSTRACT FROM AUTHOR]

Two eucalypt-feeding psyllids (Hemiptera: Psylloidea: Aphalaridae): the eucalypt shoot psyllid, Blastopsylla occidentalis Taylor and the red gum lerp psyllid, Glycaspis brimblecombei Moore are reported from Israel for the first time. Both species belong to Spondyliaspidinae, a subfamily of jumping plant lice that feed generally on Myrtaceae, mainly eucalypts. The psyllids were collected from Eucalyptus camaldulensis Dehnh., a dominant eucalypt species in Israel. A summary of the global distribution and the host trees of the two psyllids are provided and their potential threat to eucalypts in Israel is discussed. Diagnostic information to distinguish between the two psyllids is presented, with an identification key for the adults of six eucalypt-feeding psyllid species in the Western Palearctic region. [ABSTRACT FROM AUTHOR]

The pre-release risk assessment, a recommended practice in biological control programmes, was carried out before introducing Closterocerus chamaeleon (Girault), a eulophid parasitoid of the eucalypt gall maker Ophelimus maskelli (Ashmead) (Hymenoptera, Eulophidae), in Sicily, Italy. We evaluated its host specificity in laboratory small arena no-choice tests on six non-target hosts, using O. maskelli as a control species. The non-target species fit with at least one of the following criteria: a) common geographical origin; b) ecological or behavioural affinities with the target host; c) concealed habit of the preimaginal stages; d) taxonomic affinity; e) taxonomic affinity with hosts of congeneric parasitoids of the candidate agent; and f) presence in Italy/Sicily. Closterocerus chamaeleon performed an oviposition sequence of 10 recognisable behaviours, always leading to parasitization when exposed to O. maskelli. The same behaviour sequence was carried out on the gall maker Leptocybe invasa Fisher et La Salle, the only non-target species living on Eucalyptus, but just until Step 6, i.e. until ovipositor extraction and insertion, and never until egg-laying. All of the other non-target hosts were ignored. Furthermore, the adult parasitoid longevity was assessed in three rearing conditions: 1) no food/no parasitisation permitted; 2) food/no parasitisation permitted; and 3) food provided after parasitisation. Adult wasp longevity was significantly higher in treatment 2 (21.1 days ± 4.1 SE) than in treatment 1 (3.6 days ± 0.5 SE) or 3 (3.8 days ± 0.6 SE). Laboratory tests carried out in this study on C. chamaeleon indicated high host selection ability, later confirmed by our post-release field data. [ABSTRACT FROM AUTHOR]

The genus Eucalyptus, native to Australia, is the host of psylloid insects such as the red gum lerp psyllid Glycaspis brimblecombei, a major Eucalyptus pest introduced into Brazil among other countries. The encyrtid Psyllaephagus bliteus is a primary parasitoid used in the biological control of G. brimblecombei. This study aimed to determine the parasitism of G. brimblecombei by P. bliteus released in eucalyptus plantations. Investigations were carried out in a 19-ha eucalyptus plantation comprised of 9-year-old Eucalyptus camaldulensis (Myrtaceae) in the municipality of Luiz Antônio, São Paulo State, Brazil. Twenty P. bliteus pairs were released at five points in the study area between May and September 2006 and 2007 approximately every 20 days. For evaluation of parasitism, ten leaves per twig were randomly selected and unparasitized nymphs of G. brimblecombei, mummies (parasitized nymphs of G. brimblecombei) and empty mummies (after emergence of P. bliteus adults) were counted on their abaxial and adaxial parts before and after each release of P. bliteus. The parasitism rates of G. brimblecombei in 2006 and 2007 were 0.21-5.92% and 0.28-7.03% in the control; these values rose to 28.28-78.57% and 30.32-79.34%, respectively, in areas involved in parasitoid release. Parasitism levels of G. brimblecombei nymphs in areas with P. bliteus release were affected by the environmental temperature, which is discussed as a potential limitation to the establishment of this parasitoid and to its effectiveness as a biological control agent. [ABSTRACT FROM AUTHOR]

In this study, the occurrence of Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae) was recorded for the first time on Eucalyptus camaldulensis (Myrtaceae) leaves in Turkey. In addition the generalist predator Anthocoris nemoralis Fabricius (Hemiptera: Anthocoridae) and the parasitoid of the red gum lerp psyllid Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) were also found as natural enemies. P. bliteus is also for the first time recorded in Turkey. [ABSTRACT FROM AUTHOR]

Forest plantations with Eucalyptus spp. (L' Hér) in Brazil are highly yielding. However, this activity is more and more threatened due to interactions with phytophagous insects, especially by exotic species, such as the red gum lerp psyllid Glycaspis brimblecombei Moore (Hemiptera: Psyllidae). This study aimed to evaluate the resistance in eucalyptus against the psyllid in oviposition and biological development assays, attempting to identify potential genotypes resistant to the pest for forest plantations. In addition, we tested the hypothesis of that concentration of total phenolics and lignin, and amount of epicuticular wax were associated with the expression of resistance. Results showed that there was variation in the levels of resistance among the genotypes assessed. Oviposition non-preference was observed on Eucalyptus citriodora (Hook) in free-choice and no-choice tests, and Clone FP was least preferred in the no-choice test. The genotypes E. citriodora and Clone FP provided 100 % nymphal mortality, and Clones FP and FP also affected negatively the G. brimblecombei development by lengthening the duration of the nymphal stage and reducing adult emergence. Clone FP had higher concentration of total phenolics and larger contact angle formed between the water droplet and leaf surface, which may be associated with thicker layer of epicuticular wax on the leaves, and one of the causes of high nymphal mortality. Thus, the use of the resistant genotypes of eucalyptus screened against G. brimblecombei is a promising and viable alternative for forest plantations infested with this pest. [ABSTRACT FROM AUTHOR]

We investigated how fungal decomposer (aquatic hyphomycetes) communities colonizing alder and eucalyptus leaf litter respond to changes in habitat characteristics (transplantation experiment). We examined the breakdown of leaf materials and the associated fungal communities at two contrasting sites, a headwater stream (H) and a midreach (M). Agroforestry increased from headwater to midreach. One month after the start of experiments at both sites, some leaf samples from the midreach site were transplanted to the headwater site (M-H treatment). Although both sites showed similar dissolved inorganic nutrient concentrations, eucalyptus leaves initially incubated at the midreach site (M, M-H) increased their breakdown rate compared to those incubated along the experiment at the headwater site (H). Alder breakdown rate was not enhanced, suggesting that their consumption was not limited by nutrient availability. Sporulation rates clearly differed between leaf types (alder > eucalyptus) and streams (H > M), but no transplantation effect was detected. When comparing conidial assemblages after transplantation, an inoculum effect (persistence of early colonizing species) was clear in both leaf species. Substrate preference and shifts in the relative importance of some fungal species along the process were also observed. Overall, our results support the determining role of the initial conditioning phase on the whole litter breakdown process, highlighting the importance of intrinsic leaf characteristics and those of the incubation habitat. [ABSTRACT FROM AUTHOR]

Eucalyptus globulus is the most important forest species in Uruguay, with more than 250,000 ha of commercial plantations. Despite its high susceptibility to diseases, production losses caused by foliar diseases have not been properly quantified in this country. This study analyzes the effects of foliar damage on growth and survival using data from a progeny test of E. globulus naturally infected by Teratosphaeria leaf disease and eucalypt rust ( Puccinia psidii). The severity of leaf spots and defoliation were quantified 8 months after planting and tree growth and mortality were evaluated 2, 4 and 6 years later. The trial had a high incidence of foliar damage, with a mean leaf spot severity of 28.7% and a mean defoliation of 37%. The greatest impact of foliar damage, both on growth rate and mortality, occurred in the first 2 years after damage was assessed. During this period, leaf spot severity less than 40% and defoliation below 50% did not affect growth, while survival was affected when leaf damage was 70% or greater. By the sixth year both stem growth and survival were affected by severe foliar damage (spotting or defoliation of 80% or more), with a loss of up to 25% in diameter and an accumulated mortality over 70%. It has been established for the first time that under the intensive Uruguayan productive conditions, E. globulus trees can tolerate a relatively high degree of leaf spotting or defoliation but severe foliar damage in the first months can cause considerable production losses, putting at risk the economical viability of this species. [ABSTRACT FROM AUTHOR]

The bronze bug Thaumastocoris peregrinus Carpintero & Dellapé (Hemiptera: Thaumastocoridae), originating in Australia, has been rapidly spreading in eucalyptus plantations in the Southern Hemisphere, including South Africa, Zimbabwe, Argentina, Uruguay, Paraguay and Chile. In Brazil, it was detected in 2008 in the states of Sao Paulo and Rio Grande do Sul. Due to incomplete knowledge about the biology of this pest, the present study evaluated the bioecology of T. peregrinus in different eucalyptus species and hybrids. The genetic materials utilized were: Eucalyptus camaldulensis, E. urophylla, E. grandis, '1277' (Hybrid E. grandis x camaldulensis-HGC), 'VM-1' (Hybrid E. urophylla x camaldulensis-HUC) and 'H-13' (Hybrid E. urophylla x grandis-HUG). The experiment was conducted in a climate-controlled chamber at a temperature of 26 ± 1°C, r.h. = 70% ± 10% and 12 h photophase. The biology of different genotypes indicated that the species E. urophylla and E. grandis are the most suitable for the development and reproduction of T. peregrinus, although all treatments enabled the bronze bug to develop and produce descendants. T. peregrinus developed and reproduced in the principal vegetal materials planted in the southern, central-west and northeastern regions of Brazil, constituting a potentially damaging insect pest to eucalyptus plantations. [ABSTRACT FROM AUTHOR]

A novel homothallic species of Phytophthoraproducing semipapillate sporangia on sympodially branching sporangiophores, thick-walled oospores in smooth-walled oogonia, and paragynous antheridia is described here as Phytophthora elongatasp. nov. DNA sequencing of the internal transcribed spacer (ITS) DNA and coxI gene confirm P. elongataas a distinct species within ITS clade 2. It has been isolated in the northern jarrah forest of Western Australia (WA) from the roots and collars of dead and dying Eucalyptus marginataand occasionally Corymbia calophyllain rehabilitated bauxite mine pits. It has also been associated with dead and dying plants of several mid- and understorey species in the northern and southern jarrah forest – Banksia grandis, Leucopogon propinquus, Dryandra squarrosaand an Andersoniasp., as well as the monocotyledonous Xanthorrhoea preissii, X. gracilisand Patersonia xanthina. P. elongatahas also been isolated from sandy soils and loams in Victoria in eastern Australia. The pathogenicity of P. elongatato E. marginataand Banksiaspp. has been shown in this and earlier studies. Due to the uniformity of the ITS DNA and cox1 sequence data in WA, P. elongatamay be the result of a recent clonal introduction. More pathogenicity tests on a wider range of native plant species are needed to assess the host range of P. elongataand its invasive potential in WA. [ABSTRACT FROM AUTHOR]

Toxicity by contact and by ingestion of lufenuron, flufenoxuron, lambda (λ)-cyhalothrin, cypermethrin, thiamethoxam and five entomopathogenic insecticides (three formulations of Beauveria bassiana, a compound containing spores of Metarhizium anisopliae var . acridum, and a mixture of Brevibacillus laterosporus, Bacillus licheniformis and Bacillus chitinosporus) were evaluated on adults of the Eucalyptus snout-beetle Gonipterus scutellatus Gyllenhal (Coleoptera: Curculionidae) under laboratory conditions. By contact, entomopathogenic fungus B. bassiana EC and the pyrethroid λ-cyhalothrin exhibited the highest efficiency, achieving 100 and 97.5% mortality, respectively. By ingestion, the highest mortality was obtained by B. bassiana EC (100%) and thiamethoxam (95%). Flufenoxuron and lufenuron, bacteria mixture and M. anisopliae showed a weak toxicity. Furthermore, we found a sex-biased mortality, being males more affected. Due to the good performance and low risk to humans and environment, B. bassiana EC (strain PPRI 5339) appears to be the most promising product to promote an IPM programme in South Africa. [ABSTRACT FROM AUTHOR]

Chrysoporthe cubensisis an important pathogen of commercially planted Eucalyptusspecies (Myrtaceae) in tropical and subtropical parts of the world where these trees are planted as non-natives. Although the majority of Eucalyptusspp. are native to Australia, Chr. cubensisis not common there and has been reported only once from naturally growing Eucalyptus marginatain Western Australia. Chr. cubensisis able to infect hosts in the Myrtaceae and Melastomataceae other than Eucalyptus, but has not been found on hosts other than Eucalyptusin Australia. Recently, fruiting structures resembling those of Chr. cubensiswere discovered on Tibouchina heteromalla, planted as a non-native in the Botanical Gardens in Cairns, northern Queensland. These fruiting structures and resulting isolates were characterised as Chr. cubensisin this study. Pathogenicity studies found that Corymbiaspp., including commercially important spotted gum, are susceptible along with E. pilularisand E. dunnii. The discovery of Chr. cubensison a non-native plant in the northern part of Australia is important as it might imply that the pathogen has been introduced into the country and pose a significant threat to native Eucalyptusforests. Alternatively, this fungus might occur naturally in the area on hosts other than Tibouchina, possibly Eucalyptusor related species, and that Australia forms part of its native range. [ABSTRACT FROM AUTHOR]

Ecological processes such as plant-animal interactions have a critical role in shaping the structure and function of ecosystems, but little is known of how such processes are modified by changes in landscape structure. We investigated the effect of landscape change on mistletoe parasitism in fragmented agricultural environments by surveying mistletoes on eucalypt host trees in 24 landscapes, each 100 km2 in size, in south-eastern Australia. Landscapes were selected to represent a gradient in extent (from 60% to 2% cover) and spatial pattern of remnant wooded vegetation. Mistletoes were surveyed at 15 sites in each landscape, stratified to sample five types of wooded elements in proportion to their relative cover. The incidence per landscape of box mistletoe (Amyema miquelii), the most common species, was best explained by the extent of wooded cover (non-linear relationship) and mean annual rainfall. Higher incidence occurred in landscapes with intermediate levels of cover (15-30%) and higher rainfall (>500 mm). Importantly, a marked non-linear decline in the incidence of A. miquelii in low-cover landscapes implies a disproportionate loss of this species in remaining wooded vegetation, greater than that attributable to decreasing forest cover. The most likely mechanism is the effect of landscape change on the mistletoebird (Dicaeum hirundinaceum), the primary seed-dispersal vector for A. miquelii. Our results are consistent with observations that habitat fragmentation initially enhances mistletoe occurrence in agricultural environments; but in this region, when wooded vegetation fell below a threshold of ~15% landscape cover, the incidence of A. miquelii declined precipitously. Conservation management will benefit from greater understanding of the components of landscape structure that most influence ecological processes, such as mistletoe parasitism and other plant-animal mutualisms, and the critical stages in such relationships. This will facilitate action before critical thresholds are crossed and cascading effects extend to other aspects of ecosystem function. [ABSTRACT FROM AUTHOR]

The article reports on a study related to the death of Eucalyptus plants due to the infection of plant pathogen Cryphonectriaceae that cause stem canker diseases on the Eucalyptus. The study revealed dying Eucalyptus grandis by an unknown member of the Cryphonectriaceae. As per the study, deoxyribonucleic acid (DNA) sequence comparisons showed presentation of new genus and species by the Indonesian fungus that can be distinguished by orange limited stromatic tissue and absence of paraphyses.

The article focuses on a study related to the infection of the Puccinia psidii that causes rust disease in Eucalyptus plants in Brazil. It informs that the effect of height gradient on rust incidence in eucalyptus plants was evaluated during the study to assess the correlation between plant heights, duration of leaf wetness and concentration of airborne urediniospores. The study found that the pathogens are not able to infect eucalyptus plants taller than three to four meters of height.

Abstract The sex pheromone of Mnesampela privata, an endemic pest of Eucalyptus plantations in Australia, was previously identified as a single bioactive compound, (3Z,6Z,9Z)-3,6,9-nonadecatriene (C19 triene). Initial field testing of lures containing 1 mg, 5 mg or 10 mg of C19 triene (>98% purity) caught no or very few male M. privata. (3Z,6Z,9Z)-3,6,9-Henicosatriene (C21 triene) was identified as an additional minor pheromone component in abdominal tip extracts of M. privata females from Tasmania. Levels of both compounds extracted from individual females varied greatly, but the ratio was relatively constant at 33:1 C19:C21 trienes. Electroantennograms (EAG) of synthetic C21 triene with male M. privata gave positive but consistently lower responses than elicited by the C19 triene. Field tests showed that the addition of 1-6% C21 triene to 1 mg C19 triene significantly increased trap catch and the detection of M. privata in plantations. Traps baited with 16:1 ratio caught significantly more moths than those baited with a ratio approximating that of females. [ABSTRACT FROM AUTHOR]

Quambalaria eucalypti, a serious pathogen of Eucalyptus, is believed to be native to Australia and introduced into various southern hemisphere countries, including Uruguay. In this study we record the discovery of Q. eucalypticausing leaf lesions on Myrceugenia glaucescens, a tree native to Uruguay. The identity of the pathogen was confirmed using DNA sequence comparisons of the internal transcribed spacer (ITS) region of the rDNA operon, as well as morphological characteristics. This is the first record of the pathogen on a host other than Eucalyptus. It clearly indicates a disturbing example of an alien invasive pathogen having undergone a host-shift from non-native Eucalyptusto a native tree in Uruguay. [ABSTRACT FROM AUTHOR]

There are over 60 species of Mycosphaerella known from eucalypts, and several are serious pathogens of Eucalyptus globulus plantations in Australia and elsewhere, being associated with a syndrome called Mycosphaerella leaf disease. The Green Triangle region (south-west Victoria and south-eastern South Australia) is a major focus of the expansion of E. globulus in Australia, with over 125 000 ha planted since 1998. In this paper, we report the first comprehensive survey for species of Mycosphaerella in this expanding estate and assess the damage from these species from 1999 to 2002. There was an increase in the incidence of Mycosphaerella leaf disease in these plantations during the survey period, and five species of Mycosphaerella were identified from E. globulus plantations in the region: M. cryptica, M. nubilosa, M. parva, M. tasmaniensis and M. aff. vespa. M. cryptica, M. nubilosa and M. parva were the most common. M. cryptica was also found in native forest in the region, as was Sonderhenia eucalyptorum (telemorph, M. swartii). Morphological and phylogenetic comparisons were made with previously described species and confusion over the taxonomy of some of these species is discussed. [ABSTRACT FROM AUTHOR]

Mundulla Yellows (MY) is a dieback disorder of Eucalyptus and other native Australian plants in the south-east of South Australia. Recent attempts to find a causal biotic agent have failed. The history of trace element deficiencies in the area and recent work suggest that a strong association of MY with abiotic soil factors is likely. Because lime chlorosis and trace element deficiencies are involved, the MY situation is complicated to explain. This paper attempts to clarify the situation and explain why the symptoms of MY are actually the symptoms of a lime-induced chlorosis. [ABSTRACT FROM AUTHOR]

Ceratocystis spp. include important pathogens of trees as well as apparently saprophytic species. Four species have been recorded on Eucalyptus grandis in Australia, of which only one, C. pirilliformis Barnes and M.J. Wingf., is known to be pathogenic. A recent survey of pests and diseases of Eucalyptus trees in northern Queensland revealed a species of Ceratocystis associated with the tunnels made by the aggressive wood-boring insect Phoracantha acanthocera (Macleay) (Cerambicydae: Coleoptera). The aim of the present study was to identify the fungus based on morphological characteristics and comparisons of DNA sequence data for three gene regions. The fungus peripherally resembles C. fimbriata Ell. and Halst. but differs from this species most obviously by having much darker mycelium, longer ascomatal necks, segmented hyphae and an absence of aleuroconidia. Comparisons of combined sequence data confirmed that the Ceratocystis sp. from P. acanthocera represents an undescribed taxon, which is provided with the name Ceratocystis atrox sp. nov. C. atrox appears to have a close relationship with P. acanthocera, although its role in the biology of the insect is unknown and its pathogenicity has not been considered. [ABSTRACT FROM AUTHOR]

Rust is one of the most-damaging eucalypt diseases in Brazil and is considered a potential threat to eucalypt plantations worldwide. To determine the mode of inheritance of resistance in the Eucalyptus grandis—Puccinia psidii pathosystem, ten full-sib families, generated from crosses between susceptible and resistant trees, were inoculated with a single-pustule isolate of the pathogen and rust severity was scored. The observed segregation ratios in segregating families suggested major gene control of rust resistance, although clearly incomplete penetrance, variable expressivity and minor genes are also involved in the global rust-resistance response. To identify markers linked to the resistance locus, screening of RAPD polymorphisms was conducted using bulked segregant analysis in a large full-sib family. A linkage group was built around the Ppr1 gene (P. psidii resistance gene 1) encompassing six RAPD markers, with a genetic window spanning 5 cM with the two most-closely linked flanking markers. Besides these two flanking markers, RAPD marker AT9/917 co-segregated with Ppr1 without a single recombinant in 994 meioses. This tightly linked marker should prove useful for marker-assisted introgression and will provide an initial lead for a positional cloning effort of this resistance allele. This is the first report of a disease resistance gene identified in Eucalyptus, and one of the few examples of the involvement of a major gene in a non-coevolved pathosystem. [ABSTRACT FROM AUTHOR]

The article presents the first report of a Candidatus Phytoplasma asteris-related Phytoplasma associated with eucalyptus little leaf disease in Iran.