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The invasive plant pathogen Phytophthora cinnamomi (Stramenopila, Oomycota) has been introduced into 15 of the 25 global biodiversity hotspots, threatening susceptible rare flora and degrading plant communities with severe consequences for fauna. We developed protocols to contain or eradicate P. cinnamomi from spot infestations in threatened ecosystems based on two assumptions: in the absence of living hosts, P. cinnamomi is a weakly competitive saprotroph; and in the ecosystems we treated, the transmission of the pathogen occurs mainly by root-to-root contact. At two P. cinnamomi-infested sites differing in climate and vegetation types, we applied increasingly robust treatments including vegetation (host) destruction, fungicides, fumigation and physical root barriers. P. cinnamomi was not recovered at three assessments of treated plots 6-9 months after treatments. Given the high rates of recovery of P. cinnamomi from untreated infested soil and the sampling frequency, the probability of failing to detect P. cinnamomi in treated soil was < 0.0003. The methods described have application in containing large infestations, eradicating small infestations and protecting remnant populations of threatened species.

Phytophthora ramorum causes considerable and widespread damage in nurseries, gardens and natural woodland ecosystems of the USA and Europe, and is classified as a Category 1 plant pest in Australia. It is of particular interest to Australian plant biosecurity as, like P. cinnamomi, it has the potential to become a major economic and ecological threat in areas with susceptible hosts and conducive climates. Research was undertaken in California to assess the pathogenicity of P. ramorum on Australian native plants. Sixty-nine plant species within 24 families were sourced from established gardens and arboretums, and selected based upon provenance from areas of climatic suitability for P. ramorum as well as ecological and economical importance. Foliar, branch and log susceptibility were tested using detached leaf, branch and log inoculations. Sporulation potential and chlamydospore production was also tested on detached foliage of a select mid to upper storey species. Potentially highly susceptible foliar Australian host species included Eucalyptus regnans, Isopogon cuneatus, I. formosus, Leptospermum scoparium, L. lanigerum, and Melaleuca squamea, while potentially resistant hosts included Hedycarya angustifolia, Olearia argophylla, Phyllocladus aspleniifolius, Pittosporum undulatum, and Podocarpus lawrencei. Disease incidence and severity were greater during the summer, and when the leaves were wounded. Putative sporulating hosts included Agonis flexuosa, C. ficifolia, Eucalyptus delegatensis, and E. viminalis. Highly susceptible branch hosts included E. nitens, E. sideroxylon, E. viminalis, Hardenbergia violaceae, I. formosus and N. cunninghamii, and potential bole canker hosts included E. delegatensis and E. regnans. A simulation model developed using CLIMEX suggests a high likelihood of potential distribution in Australia along coastal NSW, and in cooler, wetter regions of Victoria and Tasmania. These results extend the known potential host range for P. ramorum, con

Bauxite-processing residue must be disposed of in specifically designed facilities for long-term management. Consideration of alkalinity, salinity, sodium content, and poor nutritional status is essential for successful rehabilitation of residue disposal areas (RDA). The aim of this study was to examine the availability and distribution of the micronutrients, B, Cu, Fe, Mn, and Zn, in (i) fresh bauxite-processing residue sand (particle size >150 μm) with and without gypsum amendment, and (ii) aged residue sand from a 4-year-old rehabilitated RDA that had received past gypsum and fertiliser addition. Samples of fresh residue sand from India and Australia exhibited high alkalinity, high salinity, and sodicity. Gypsum addition significantly lowered pH, soluble Na, and alkalinity. Aged residue sand had low levels of all micronutrients, with low extractability for Zn and Mn followed by B, Cu, and Fe. Fractionation showed that 30–78% of Zn and Mn and 40–60% of B existed in non-available (residual) forms. The next most dominant fractions were the Fe and Mn oxide-bound and carbonate-bound fractions. Plant-available fractions (i.e. exchangeable and organically bound) contributed <1% of the total concentration. Total concentration was found to be a reliable indicator for Zn, Cu, and B extractability but not for DTPA-extractable forms of Fe and Mn. Leaf analysis of vegetation grown on aged residue sand indicated deficiencies of Mn and B. Results demonstrated that bauxite-processing residue sand contained very low levels of B, Mn, and Zn and these concentrations may be limiting to plant growth. Distribution of micronutrients among chemical pools was significantly influenced by pH, organic carbon, exchangeable Na, and alkalinity of residue. Nutrient management strategies that account for the characteristics of residue sand need to be developed for residue rehabilitation. Importantly, strategies to limit the conversion of nutrients to non-available forms are required to minimise

Terminal drought is a risk for wheat production in many parts of the world. Robust physiological traits for resilience would enhance the preselection of breeding lines in drought-prone areas. • Three pot experiments were undertaken to characterize stem water-soluble carbohydrate (WSC), fructan exohydrolase expression, grain filling and leaf gas exchange in wheat (Triticum aestivum) varieties, Kauz and Westonia, which are considered to be drought-tolerant. • Water deficit accelerated the remobilization of stem WSC in Westonia but not in Kauz. The profile of WSC accumulation and loss was negatively correlated with the mRNA concentration of 1-FEH, especially 1-FEH w3 (1-FEH-6B). Under water deficit, Westonia showed lower concentrations of WSC than Kauz but did not show a corresponding drop in grain yield. • The results from pot experiments suggest that stem WSC concentration is not, on its own, a reliable criterion to identify potential grain yield in wheat exposed to water deficits during grain filling. The expression of 1-FEH w3 may provide a better indicator when linked to osmotic potential and green leaf retention, and this requires validation in field-grown plants.

The gall wasp, Leptocybe invasa, is a devastating pest of eucalypt plantations, woodlots, and urban trees in the Middle East, the Mediterranean basin, Africa, India, South-East Asia, and China. It was first observed in Israel in 2000 and has since spread rapidly south and east. It reached southern Vietnam in 2002 and has since moved northward devastating nurseries and young plantations. Eighteen species of eucalypts were selected for a sentinel trial in northern Vietnam to determine their susceptibility to pathogens in the region. They were also rated for the impact of Leptocybe invasa. Leptocybe invasa was capable of feeding and forming galls on 13 species from six sections within Eucalyptus and one species of Corymbia. The impact was greater in the nursery. Five of the Eucalyptus spp. which were susceptible in the nursery were not damaged in the field. The most susceptible hosts in Vietnam were E. camaldulenis, E. grandis, and E. tereticornis, both in the nursery and field trial. Variation in the susceptibility of provenances of E. camaldulensis, E. urophylla, and E. grandis were observed, which is promising for breeding for resistance and long-term control.

It has been an exciting 12 months since the last update on the CPSM. Since that time there have been 3 PhD, 1 Masters and 3 Honours student completions. There have been new species of Phytophthora described from our native woodlands with many more waiting to be described, we have fished successfully for Phytophthora throughout Western Australian waterways, we've learnt how to eradicate P. cinnamomi from some of our native ecosystems across Australia, how some of our native plants respond to treatment to phosphite and how this treatment can be optimised, how satellite and airborne remote sensing technologies can be used to monitor and detect decline in tree health, the effect of Phytophthora on our remarkable fauna, and how P. cinnamomi appears to survive in black gravel soils of bauxite mines. Newly initiated projects will lead to exciting discoveries, including the sequencing of the entire P. cinnamomi genome, the interaction between P. cinnamomi and woylies and bandicoots, the potential spread of P. cinnamomi by feral pigs, the susceptibility of Australian native plants to P. ramorum, the biology, ecology and management of Phytophthora spp. in nurseries, and the mechanisms of survival of P. cinnamomi in a range of different soils in our natural ecosystems. Finally, the CPSM was instrumental in a successful bid for the State Centre of Excellence for Climate Change and Woodland and Forest Health with 27 national and international collaborating partners and this will be hosted by Murdoch University and have a close alliance with the CPSM. This talk will give a brief overview of some of these exciting research developments.

Taxa trials of various Eucalyptus species in tropical northern Australia act as sentinel planting, trapping norrnally cryptic endemic fungi from natural ecosystems. Over the past 6 years we have surveyed many such trials in northern Australia resulting in new host records and distributions and new species descriptions. Sentinel trials of endemic tropical Eucalyptus species planted in Asia in regions known to harbour devastating pathogens absent from Australia have been established and are providing valuable information on host species susceptibility to these pathogens.

Tuart (Eucalyptus gomphocephala) is an iconic woodland tree, endemic to Western Australia, and is one of the few eucalypts able to dominate on calcareous soils. Unfortunately, less than one third of the original extent of the E. gomphocephala woodland ecosystem remains in existence today, largely as a result of clearing for urbanisation, agriculture and industry. Equally disturbing is the extensive decline of the E. gomphocephala ecosystem within the Yalgorup region, south of Mandurah, from unknown but probably complex abiotic andlor biotic causes. The recently described species Phytophthora multivora was isolated from the rhizosphere of declining tuart and may be contributing to this decline. A large collaborative, integrated research effort is focused on finding the cause(s) of this decline. Intensive ground-based studies are being used in conjunction with digital remotely sensed imagery and other spatially explicit datasets to aid establishment of research sites, map the spatial and temporal pattern of the decline with the major objective to find strong correlations with abiotic andlor biotic factors. The historical trend in canopy cover of areas of E. gomphocepha/a woodland can be accurately determined across the landscape using medium resolution (25m) LandsatTM-derived satellite data. Areas of particular interest were 'ground-truthed' in the present study to enable establishment of field sites according to changes in canopy cover over a 17 year period. High resolution (0.5 - 1m) Digital Multi-Spectral Imagery (DMSI) was then acquired for these sites and trees and shrubs of interest located using a differential GPS system. Detailed canopy assessments, foliar analysis, soil analysis and injection treatments have been completed for each site. Correlations between indicators of canopy health and a range of established spectral indices were examined. Annual DMSI has been acquired to detect changes in E. gomphocepha/a canopy and patterns of decline within the landsca

This chapter covers the phylum of plants that dominates the worlds land surface, phylum Anthophyta (the angiosperms). The main features of their morphology, internal structure, nutrition and reproduction are described to help explain the basis of their success. We also consider some of their special adaptations to the Australian environment.

The most serious foliar disease of eucalypt plantations in WA is Mycosphaerella leaf disease (MLD) (1). Since the commencement of the plantation industry, several fungal species contributing to MLD, previously known only in eastern Australia or overseas, have been reported on E. globulus in WA. Initially only three species were identified (2). More recently, five new records from WA (M. aurantia, M. ellipsoidea, M. mexicana and M. fori) have been identified that have not been recorded elsewhere in Australia (1, 3). Currently, 13 species of Mycosphaerella have been recorded in WA from Eucalyptus (3). Re‐examination of cultures adds six new species that have yet to be described from E. globulus in WA. The impact of MLD on growth of E. globulus plantations in WA was examined in a chemical exclusion trial at two plantations in the Albany region.

The aim of our experiments was to develop protocols that can be used to contain and eradicate spot infestations of P. cinnamomi that, if untreated, are likely to threaten extensive areas of native vegetation or areas of high conservation value. Treatment regimes were guided by two assumptions: 1) within the selected sites, transmission of the pathogen is by root-to-root contact, and 2) the pathogen is a weakly competitive saprotroph. In Western Australia (WA), treatment and control plots were set-up along an active disease front within scrub-heath vegetation dominated by Banksia spp. Treatments, applied sequentially and in combination, included: 1) destruction of the largest plants within disease free vegetation forward of the disease front; 2) destruction of all plants to create a ‘dead zone’; 3) installation of physical root barriers and subsurface irrigation for the application of fungicide/s; 4) surface applications of fungicides selective against oomycetes (triadiazole and metalaxyl-M), and 5) surface injection and deep (± 1 m) treatments with Metham-sodium. In a separate experiment in Tasmania (TAS), combined treatments including vegetation removal, Ridomil and Metham-sodium and root barriers, or Ridomil and root barriers alone, were applied to experimental plots within active disease centres in Eucalyptus-Banksia woodland. In the WA experiment, P. cinnamomi was not recovered (by soil baiting) from plots after treatment with Ridomil and metham-sodium. In the TAS experiment, similar results were achieved with combined treatments (vegetation removal + Ridomil + metham sodium) but in plots treated with Ridomil alone, recoveries of P. cinnamomi increased after initially showing a significant reduction in recoveries.

Many diseases of Eucalyptus species have emerged as pathogens in exotic plantations. Guava rust (Puccinia psidii), cryphonectria canker (Crysoporthe cubensis) coniotherium canker (Colletogloeopsis zuluensis) and Kirramyces leaf blight (Kirramyces destructans) are all serious pathogens that have not been found in native forests or in plantations in Australia (Burgess & Wingfield 2002; Cortinas et al. 2006; Glen et al. 2007; Wingfield et al. 2001). The susceptibility to these pathogens of Eucalyptus spp. commonly used in exotic plantations is known; however the susceptibility of many Eucalyptus spp. found only in natural ecosystems in Australia is unknown. There are two main uses of sentinel plantations. Firstly, tree species known to be susceptible to different pathogens can be planted within the natural environment to try and trap pathogens from their surroundings. In Australia, taxa trials planted in different environments act as sentinel plantings. By surveying these taxa trials we have collected and described a number of new eucalypt pathogens and reported the presence in Australia of Kirramyces destructans. The second use for sentinel planting is where many tree species are planted in a region known to harbour certain pathogens. In this manner the susceptibility of the different tree species can be determined.

Australasia to identify emerging plant diseases, carriers of these diseases, and the role of hosts in the transmission of disease. In Australia, a cause for concern and currently listed as a category 1 emergency pest pathogen is Phytophthora ramorum. It has a wide host range and causes widespread damage in nurseries and private estates across Europe and is devastating coastal forest ecosystems of western USA, mainly in California (Rizzo and others 2002, Werres and others 2001). Several Australasian plant species, including Griselinia littoralis (New Zealand broadleaf), Eucalyptus haemastoma (Australian scribbly gum), and Pittosporum undulatum (Victorian box), have already been listed as natural hosts of P. ramorum based on field observations and pathogenicity tests in the USA and Europe (Hüberli and others 2006, RAPRA 2007). While P. ramorum has not been detected in New Zealand or Australia, a preliminary study has identified ecosystems that could be conducive to disease development in Australia (W. Smith unpublished data). It is a pathogen that the region cannot afford as the threat and management implications of this pathogen on natural ecosystems, agriculture and horticulture may potentially be far worse than that currently posed by P. cinnamomi (O’Gara and others 2005). The study aims to provide knowledge of potential hosts and therefore carriers of the pathogen, provide data for the establishment of robust quarantine practices and reduce the risk of an introduction of P. ramorum into Australasia.

The pathogenicity of Phytophthora ramorum on Australian native plants was assessed using detached leaf and branch inoculations. Results indicate the potential for P. ramorum to infect and colonise a range of Australian native plant species from different families.

Forest, woodland and shrubland declines are widespread and in many cases severe in Western Australia and elsewhere in temperate Australia. The causes are often complex, poorly understood and include: declining rainfall, changes in groundwater levels and quality, pathogens and pests, excess nutrients, salinity, changing fire regimes, and weed competition to name a few. This presentation reviews current projects by members of the State Centre of Excellence on Climate Change Woodland and Forest Health and other researchers based at Murdoch University. The Centre, a co-operative venture with the University of Western Australia, the Department of Environment and Conservation and approximately 26 other partners, has four key Research Programs: Climate Change, forest and woodland declines; Decline Ecology; Restoring Biodiversity Values, and Education, Training, Communication and Policy. The aim of the Centre is to bring together multi-disciplinary teams of research scientists to (a) determine the factors that contribute to declines, (b) determine how they interact with climate change, (c) develop adaptive management strategies to mitigate the declines and to restore ecosystem function and health, and (d) work with agencies, industry and the wider community to ensure research findings are rapidly and effectively implemented through policy, legislation and community engagement. Keywords: Climate Change; Remote Sensing, Restoration, Fauna, Flora

To understand the pathway used by Phytophthora cinnamomi Rands to penetrate the bark of jarrah, the present study describes unwounded periderm and rhytidome development. Periderm formation is described from its initiation in 4-week-old seedlings to the formation of rhytidome in saplings. Periderm in young seedlings consists of a single type of phellem, namely thin-walled suberised cells. In older seedlings where multiple layers of periderm have formed, layers of thick-walled lignified phellem cells in compacted bands alternate with thin-walled suberised cells. Rhytidome formation in older lignotuberous seedlings and in sapling jarrah occurs through the isolation of secondary phloem by periderm. The rhytidome consists of expanded and partially disintegrated secondary phloem tissue sandwiched between layers of phellem cells. Localised periderm formation beneath stomata results in the formation of lenticels, which are ephemeral features. Superficial periderms occur at sites of leaf and shoot abscission, and of lateral shoot emergence. Concealed axillary shoots lack cuticle on emergence. As the trees age, the internal production of lignified and suberised periderm and rhytidome results in an impenetrable barrier to invasion by P. cinnamomi. However, external sites including lenticels and leaf and shoot abscission and emergence areas, all provide points of ingress in unwounded stems.

The present study investigates whether previously acquired boron (B) in mature leaves in white lupin can be retranslocated into the rapidly growing young reproductive organs, in response to short-term (3 d) interrupted B supply. In a preliminary experiment with white lupin in soil culture, B concentrations in phloem exudates remained at 300-500 μM, which were substantially higher than those in the xylem sap (10-30 μM). The high ratios of B concentrations in phloem exudates to those in the xylem sap were close to values published for potassium in lupin plants. To differentiate 'old' B in the shoot from 'new' B in the root, an experiment was carried out in which the plants were first supplied with 20 μM 11B (99.34% by weight) in nutrient solution for 48 d after germination (DAG) until early flowering and then transferred into either 0.2 μM or 20 μM 10B (99.47% by weight) for 3 d. Regardless of the 10B treatments, significant levels of 11B were found in the phloem exudates (200-300 μM in 20 μM 10B and 430 μM in 0.2 μM 10B treatment) and xylem sap over the three days even without 11B supply to the root. In response to the 0.2 μM 10B treatment, the translocation of previously acquired 11B in the young (the uppermost three leaves), matured, and old leaves was enhanced, coinciding with the rise of 11B in the xylem sap (to >15 μM) and phloem exudates (430 μM). The evidence supports the hypothesis that previously acquired B in the shoot was recirculated to the root via the phloem, transferred into the xylem in the root, and transported in the xylem to the shoot. In addition, some previously acquired 11B in the leaves may have been translocated into the rapidly growing inflorescence. Phloem B transport resulted in the continued net increment of 11B in the flowers over 3 d without 11B supply. However, it is still uncertain whether the amount of B available for recirculation is adequate to support reproductive growth until seed maturation.

Arbuscular Mycorrhizal (AM) status of native plants in the tropical forest of northern Thailand was surveyed. Twenty four framework tree species, used to forest restoration were examined at 3 sites: FORRU=s research tree Nursery (FN), Forest Restoration plot (FR) and Natural Forest (NF). Eleven dominant herb species were examined at 2 sites: Degraded Watershed (DW) and Forest Soil extraction area (FS). Rhizosphere soil samples were collected and AM fungal spores were counted and identified morphologically. Most plant species were intensively colonized by AM fungi except Cyperus cyperoides. Twenty four AM species were identified: Glomus (15 species), Acaulospora (6 species) and Scutellospora (3 species). Glomus rubiforme was the dominant species. Spore density varied from 16.1 to 97.4 per 100 g soil (averaged 59.7). Spore number at DW and FS were 129 and 479 spores, respectively, with species richness of 6 and 8, respectively. Spore number at FN, FR and NF were 1,152, 2,337 and 1,376 spores, respectively, with species richness of 17, 21 and 15, respectively. The AM diversity was lower in the sites dominated by herbs than in sites examined for trees. In the deforested sites, reduced plant diversity was related with reduced mycorrhizal diversity. In contrast, the trial plot had the highest AM fungal community. Therefore, the forest restoration techniques allow tree species grown in nursery to become AM associated. The association is still maintained after planting out trees in restored area.

The present study aims to understand whether genotypic differences in grain iron (Fe) concentration in four rice genotypes are related to its association with protein bodies containing phytate-rich inclusions. Rice genotypes with high and low grain Fe concentrations in unpolished brown rice were grown in a greenhouse at Chiang Mai, Thailand, and grains were harvested at maturity. The presence of protein bodies and phytate-rich inclusions in rice grain tissues were examined by means of light and transmission electron microscopy (TEM). The composition of mineral elements in different grain tissues was examined using energy dispersive X-ray microanalysis (EDX) and chemical analysis. The relative distribution pattern of protein bodies in the tissues was similar among the four rice genotypes, which resembled the pattern of grain N concentrations in these tissues. The high grain Fe genotypes (based on brown rice Fe concentration) had more protein bodies containing phytate-rich inclusions in the embryo and aleurone layer tissues than the low Fe genotypes. Phytate-rich inclusions were not detected in the endosperm tissues in all genotypes. In conclusion, the presence of protein bodies with phytate-rich inclusions predominantly in the embryo and aleurone regions of the grain is an important parameter contributing to the variation in brown rice Fe concentration among the genotypes, but not in the white rice (the endosperm). Iron associated with the phytate-rich inclusions present in the embryo and aleurone layer tissues are largely lost during the polishing process to produce white rice.

Specimens of the genus Amanita, collected from northern Thailand and deposited in the fungal herbarium of Chiang Mai University and some overseas herbaria were studied. Twenty-five taxa, including eighteen new to Thailand, are described briefly. A key to species is provided. The new records for Thailand are A. alboflavescens, A. avellaneosquamosa, A. chepangiana, A. clarisquamosa, A. flavipes sensu lato, A. fritillaria, A. fuliginea, A. hongoi, A japonica, A. manginiana sensu W.F. Chui, A. obsita, A. ovalispora, A. pseudoporphyria, A. rubrovolvata, A. sinensis, A. sinocitrina, A. subglobosa, and A. virgineoides. A type study of A. pudibunda is included. Amanita frostiana sensu R. Heim is proposed to be properly diagnosed as A. rubrovolvata.

Terminal drought tolerance of wheat is a major target in many areas in the world and is a particular focus in Western Australia. It is widely considered to relate to water soluble carbohydrate (WSC) levels such as fructan in the stem, as the head is maturing. Fructan exohydrolases are key enzymes during both fructan biosynthesis and mobilization. The wheat genome sequences of three fructan 1-exohydrolase (1-FEH) genes with seven exons and six introns were isolated by using the available 1-FEH w2 cDNA sequence. The major size differences among the three genes were located in intron 1 and intron 4. The three 1-FEH genes were mapped to Chinese Spring chromosome 6A, 6B and 6D based on polymerase chain reaction (PCR) polymorphisms and Southern hybridization. 1-FEH-6A, -6B and -6D corresponded to published cDNA sequences 1-FEH w1, w3 and w2, respectively. The overall correlation of the mRNA accumulation profile for the 1-FEH genes in stem and sheath leaf tissue in relation to the profile of soluble carbohydrate accumulation was consistent with their postulated role in stem soluble carbohydrate accumulation. The accumulation of the 1-FEH-6B (1-FEH w3) mRNA was 300 fold greater than that of 1-FEH-6A and -6D. The mRNA accumulation continued after the stem water soluble carbohydrate concentrations reached a peak, consistent with a role of 1-FEH-6B in the breakdown of soluble carbohydrate. The relationship between the 1-FEH genes and soluble carbohydrate accumulation is discussed and the 1-FEH-6B gene in particular is suggested to provide a new class of molecular marker for this trait.

Eucalyptus globulus is the predominant exotic hardwood plantation species in Western Australian (WA), and is often planted adjacent to native eucalypt forests. The increase in number of Mycosphaerella species associated with Mycosphaerella leaf disease (MLD) in E. globulus plantations in WA in the past decade has raised concern about the possible movement of pathogens between the native forests and plantations. In order to determine whether the introduction of new E. globulus genetics into WA may have further exacerbated this situation, juvenile and adult foliage were taken from a genetics trial near Albany, WA consisting of 60 full-sib families and Mycosphaerella species identified using morphological and molecular tools. Eleven species of Mycosphaerella were identified from one plantation: Mycosphaerella fori (Pseudocercospora fori) and Mycosphaerella ellipsoidea are new records for Australia; Mycosphaerella tasmaniensis (Passalora tasmaniensis) and Mycosphaerella suttoniae (Kirramyces epicoccoides) are new records for WA; and Mycosphaerella nubilosa, Mycosphaerella cryptica, Mycosphaerella marksii, Mycosphaerella molleriana, Mycosphaerella lateralis, Mycosphaerella aurantia and Mycosphaerella parva, previously recorded for WA. The most frequently isolated species from juvenile foliage was M. marksii (77%) followed by M. nubilosa (33%). M. nubilosa was most frequently isolated from adult leaves (88%) followed by M. parva (7.5%). Three species, M. molleriana, M. lateralis and M. cryptica, were only isolated from adult leaves while M. ellipsoidea was only isolated from juvenile leaves. These records increase the number of known Mycosphaerella species from eucalypts in WA from 10 to 13. The increase in the number, distribution and impact of Mycosphaerella species contributing to MLD in WA is of concern both to the potential productivity of the plantations and the biosecurity of native WA Eucalyptus species. Continued monitoring of the plantation estate is required to

Understanding site fertility constraints has lifted productivity of eucalypt plantations in East and South-east Asia through targeted application of inorganic fertilisers. Whilst most attention has been given to the supply of nitrogen and phosphorus in silvicultural prescriptions, and inoculation with mycorrhizal fungi is being undertaken by some companies, more attention is required to diagnose and correct micronutrient disorders. For example, the incidence of boron deficiency remains a concern across the region affecting tree growth, tree form, fibre quality and possibly the extent of damage from some eucalypt pathogens. As even mild deficiencies of micronutrients such as copper, boron and manganese can alter the phenol pathway, limitations in the uptake of these elements have implications for tree defence against some fungal pathogens. Due to the high humidity and temperatures throughout the year, fungal leaf diseases such as Cylindrocladium quinqueseptatum have had a huge impact on the eucalypt plantation industry in South-east Asia. Often poor nutrition seems to be an underlying cause in disease susceptibility. However, in spite of the size of the eucalypt plantation sector, there is not an integrated understanding of biotic and abiotic causes and their interactions by the industry. Furthermore, the emergence of new eucalypt pathogens such as Kirramyces destructans and their rapid spread threatens the viability of plantations unless selection of resistant clones and breeding for resistance can keep up with the incursion of new and invasive eucalypt pathogens. In a number of countries, there is low genetic diversity in eucalypt plantations and breeding programs are yet to embrace screening for disease resistance. The challenge to a successful eucalypt plantation industry in Asia is to optimise genetics and nutrition in order to produce trees with the greatest chance of overcoming pest and disease threats. Copyright

The aim of our experiments was to develop protocols that can be used to contain and eradicate spot infestations of P. cinnamomi, nominally less than 200 m2 in extent. The experimental site in W A was an active disease front within scrub-heath, and in Tasmania experimental plots were set-up within well established but active disease centres in a heath-woodland complex. At both sites, we applied a sequence of treatments that included: (I) Vegetation destruction, (2) Physical root barriers, (3) Surface applications of fungicides, (4) Surface injection and deep application of a fumigant, and (5) Exclusion fencing. We assessed survival of P. cinnamomi by soil baiting. In both experiments, P. cinnamomi was not recovered in any of three consecutive assessments from plots after the complete treatment regime had been applied. Indirect tests on soils at the last assessment (WA only) showed no evidence of fungicide or fumigant residues that could have interfered with recoveries of P. cinnamomi. The results in both experiments are highly promising and the next step is to further evaluate the methods by treating entire discrete infestations of P. cinnamomi.

Large areas of indigenous forests, Banksia woodlands and heathlands in Australia are devastated by Phytophthora dieback disease caused by P. cinnamomi. Phosphite has been shown to be effective in controlling this pathogen on a wide range of plant species across different families. It acts both directly and indirectly on the pathogen. In order to maximise the efficacy of phosphite the physiological status of the plant at the time of phosphite application affects control needs to be understood. In Mediterranean environments, plants experience stresses due to extremes in water availability and the incidence of wild fire is high for example. Currently, nothing is known about the relative uptake of phosphite by shoots pre- and post-stress event or how stress may alter the redistribution and persistence of phosphite within woody plants. Therefore, from a management perspective when considering all of these stresses native plant communities are subjected to, it is critical to know when to apply phosphite to ensure optimal disease control. Fire and drought stresses on the efficacy of phosphite to control disease are examined independently. Management implications from the completed study are discussed.

A field trial was designed to determine whether the control of pests and pathogens by regular chemical treatments could increase volume in E. globulus plantations. There were four foliar treatments, fungicide, fungicide plus insecticide, insecticide and control. The treatment plots were separated by buffer zones. The trial involved two plantations (Bill’s and Sixpenny) over four years. A total of 500 trees were used for each treatment (n= 2000). The incidences of pests and diseases were similar between plantations over the four years of the trial. Standardised tree volumes were higher at Bill’s than at Sixpenny in each year and the rate of increase between years was also greater at Bill’s. The differences in tree volume caused by treatment by 2004 were comparatively minor, but still significant. Post hoc LSD tests showed that at Bill’s standardised tree volumes were greater when both insecticide and fungicide were added. At Sixpenny, the greatest improvements occurred with the use of insecticide alone. The improvements in volume as a result of insecticide or fungicide treatment ranged from up to 8.6% (Bill’s) to up to 13% (Sixpenny). As the increase in yields was minimal, they represented very little benefit compared to the cost of applying the treatments on a regular basis. The differences between plantations were most likely due to soil type and climate. If disease and pest incidence had been higher, chemical treatments may have been cost effective.

Phosphite is of major importance in controlling root disease caused by Phytophthora cinnamomi. It acts both directly and indirectly on the pathogen. In order to maximise the efficacy of phosphite we need to understand how the physiological status of the plant at the time of phosphite application affects control. The physiological status of plants is not constant but varies over time depending on developmental gene expression (e.g. leaf phenology, flowering/fruiting and senescence) and interactions with the environment (e.g. temperature, moisture, light, fire, nutrients and other biota). In Mediterranean environments in particular, plants experience stresses due to extremes in water availability and the incidence of wild fire is high. Furthermore, individuals and species of plants are not in synchrony due to differences in recruitment, ontogeny, longevity and rest periods. Therefore, from a management perspective when considering all of these stresses native plant communities are subjected to, it is critical to know when to apply phosphite to ensure optimal disease control. We examined each of the key environmental stresses (water excess, water deficit, fire and flowering) independently, on the efficacy of phosphite to control disease.

This book is written for practitioners and stakeholders in the fertiliser industry and for policy makers whose decisions may impact on the use of micronutrients in agriculture, horticulture and forestry. The aim of the book is to explain the growing importance of micronutrients in balanced fertilisation, to consider the micronutrient fertiliser types that are currently available and how to best use them, to assess the current market and prospects for micronutrient fertilisers, and to discuss the policy, regulatory and quality control framework needed to maximize the benefits from using micronutrient fertilisers.

The aim of this study is to assess the mycorrhizal status of Eucalyptus plantations in south China and to determine the need for inoculation. In four provinces in south China, 155 plantations were sampled for sporocarps of ectomycorrhizal (ECM) fungi, spores of arbuscular mycorrhizal (AM) fungi, and mycorrhizas over 2 years. This study revealed a low above-ground diversity of ECM fungi consisting of 15 taxa fruiting beneath Eucalyptus plantations. The most common ECM genera were Scleroderma and Pisolithus, but they were infrequent. A total of 21 AM fungi, mostly Glomus species, were recognized from spores collected from eucalypt plantations. Four Glomus species were frequently present in soils, but spore density and relative abundance of AM fungi were generally low. Eucalypt roots from all plantation sites were poorly colonized by either ECM fungi or AM fungi. A bioassay with E. urophylla as a bait host, using soils collected from 11 eucalypt plantations, confirmed low levels of inoculum of both ECM and AM fungi in field soil. This is the first integrated study on the mycorrhizal status of eucalypt plantations in China. Findings from this research can be used to encourage adoption of mycorrhizal technology by eucalypt nurseries in the region. The potential of using spores of compatible ECM fungi or collections for forest nurseries is discussed.

As eucalypt pollens contain low concentrations of lipid, enhancing pollen diets with fatty acids was hypothesised to improve honey bee longevity. Different concentrations of linoleic and oleic acid added to eucalypt pollen were trialled in small cages containing approximately 1400 bees each. Bees fed diets of redgum (Corymbia calophylla (Lindl.) Hill & Johnson, formerly Eucalyptus calophylla) pollen had the lowest mortality of 22 diets tested for 6 weeks and had life spans (50%) greater than 42 days. Linoleic acid mixed with a redgum diet in concentrations >6% corresponded to life spans of 24-25 days. Bee longevity appeared to be more sensitive to oleic acid as life spans decreased to 15-21 days when diets had concentrations >2%. The life spans of bees fed soya bean flour were 26 days on low (0.6% lipid) fat, 19 days on defatted and 20 days on full-fat diets. Bees fed lupin flour had a life span of 23 days. Adding redgum pollen to lupin flour caused increased mortality, but addition of pollen to soya bean flour was beneficial. Thus, beekeepers who choose to utilise soya bean or lupin flours as protein substitutes to pollen will have bees with reduced longevity. Bees fed redgum pollen that had been dried, crushed, irradiated and hermetically stored in a cool room for several years had similar longevity to bees fed fresh-collected and frozen redgum pollen.

Tricholoma fulvocastaneum is recorded from Thailand for the first time. This edible ectomycorrhizal fungus is associated with Castanopsis tribuloides (Fagaceae) in mixed evergreen forest in northern Thailand. Conventional and molecular methods were carried out to confirm its identity.

The jarrah (Eucalyptus marginata Donn. ex Smith) forest in Western Australia is a tall dry sclerophyll forest with a uniform overstorey dominated by jarrah. The forest extends over most of the south-western corner of Australia, with a Mediterranean climate, covering approximately 64 000 km2 (Shearer and Tippett, 1989). Jarrah ranges in height from 15-50 m and 3 m in diameter across most of its range. Jarrah has the ability to dominate a wide range of sites, especially lateritic catenas. The jarrah forest has a high level of endemism in plants. There are approximately 1200 species found over its range, including many species in the Myrtaceae, Fabaceae and Proteaceae (Shearer and Tippett, 1989). Jarrah has, and will, continue to be an important timber species because of its durability and suitability for furniture, shipbuilding, wharves, telegraph poles and structural timber in house building. Jarrah is an important ‘keystone’ species of the jarrah forest and any threats to its health and viability will have important economic, environmental and ecological consequences. The most signifi cant threat to jarrah is the introduced soilborne plant pathogen Phytophthora cinnamomi Rands.

Distinctive basidiomes of Pycnoporus sp. were observed on 5-6-year-old living Paulownia trees at two commercial plantations in Western Australia. The basidiomes were erupting through the bark, which readily peeled away to expose the rotting wood beneath. Based on internal transcribed spacer-polymerase chain reaction, the fungus was identified as Pycnoporus cinnabarinus. Under-bark inoculation of 3-year-old Paulownia fortunei trees in the glasshouse, with mycelium isolated from basidiomes on trees at the commercial plantations, resulted in the formation of dark lesions and the pathogen was re-isolated ahead of the lesion front. Benomyl and cyprodinil were the most effective fungicides at inhibiting the growth of mycelium in vitro. This is the first report of Pyc. cinnabarinus acting as a pathogen on Paulownia trees. It is likely that the pathogen enters living trees through pruning wounds or damage from sun scald. Further work is required to confirm methods of control in the field.

Leaf spots caused by Mycosphaerella spp. are of increasing concern in eucalypt plantations around the world, but few species have been reported infecting eucalypts in Asia. From leaf material collected in China, Vietnam and Indonesia, we describe three new Mycosphaerella spp.; M. vietnamiensis, M. obscuris and M. yunnanensis. Mycosphaerella crystallina, previously known only from South Africa, and M. stramenticola, previously reported from Eucalyptus leaf litter in Brazil, are new records. Mycosphaerella citri, an important pathogen of citrus, was found infecting Eucalyptus. Mycosphaerella marksii and M. suttoniae, which have been previously reported in Asia, were regularly encountered. Pseudocercospora spp. were also common throughout the region. This study highlights the potential biodiversity of Mycosphaerella spp. on eucalypts in South-East Asia.

Introduction: In Australia, the introduced soil-borne plant pathogen Phytophthora cinnamomi is listed by the Commonwealth's Environmental Protection and Biodiversity Conservation Act -1999 as a 'Key Threatening Process to Australia's Biodiversity'. It causes major epiphytotics in the Mediterranean areas of the continent receiving more than 600 mm of rainfall. In the Southwest Botanical Province of Western Australia over 2,285 native plant species of the 5,710 described are susceptible to P. cinnamomi (Shearer et al. 2004). The indirect effects of P. cinnamomi in terms of botanical impact through the loss of vertebrate and invertebrate pollinators, and loss of canopy and litter cover have yet to been determined. Recent studies indicate that the pathogen is impacting on native fauna due to loss of litter, understorey and overstorey canopy cover, food resources and refugia (Garkaklis et al. 2004). The pathogen also impacts on stream flow, water quality, and can increase salinity. Hygiene and quarantine management controls impact on mining, timber harvesting, road building, and the activities of utilities and general use of parks and reserves by the public. The plant communities impacted on in south-western Australia include the jarrah (Eucalyptus marginata) forest, the banksia woodlands and heathlands. The area of impact includes the only global biodiversity 'hotspot' in Australia (Mittermeier et al. 2004).

Introduction: Eucalyptus gomphocephala (tuart) is a magnificent woodland tree dominating the coastal dune system in the south-west of Australia, extending from near Cervantes in the north to near Busselton in the south, approximately 400km in length and frequently only 1 km wide (Boland et al. 2006). Only approximately 30,000 ha of once extensive E. gomphocephla woodland remains (Government of Western Australia2002), and there is increasing concern over its health as a severe decline of unknown cause(s) is having a major impact (Archibald et al. 2004; Edwards 2004). The present study aims to determine whether remote sensing technologies and other spatially explicit datasets can be used with ground-based studies to establish long-term monitoring sites, map spatial and temporal patterns of the decline. It will also compare and monitor quantitative changes in individual tree crown health with the key objective of finding significant correlations with abiotic and/or biotic factors. Preliminary results from this study are presented.

Historical accounts of possible B roles in the protection of tree and horticulture species against frost damage were reported as early as 1950s, with more field observations and experimental evidence since then. Although the initial reports (Anon 1958: Beltram 1958) were no more than anecdotal evidence due to the lack of proper comparative control experiments, later field and glasshouse studies have provided more reliable evidence about the involvement of B in the protection against frost damage — decreased frost-induced shoot-tip dieback or increased flowering and fruit yield, for example: in subtropical eucalypts Eucalyptus grandis (Cooling 1967: Cooling and Jones 1970) and Eucalyptus grandis x Eucalyptus urophylla (Lu and Huang 2003): apple, pear and blueberry (Blevins et al. 1996: Hanson and Breen 1985; Milovankic et al. 1990) and in birch, Scots pine, and Norway spruce (Braekke 1983). Frost-induced “white top” (bleached young leaves) has been observed in low temperature-sensitive E. urophvila and E. grandis in south China (Xu Daping. pers. comm.) where B deficient soils arc common (Dell and Malajczuk 1994). Field observations have also suggested a link between low canopy temperature and enhanced leaf tissue damage (bleached patches) in oilseed rape grown in low B soil in south-east China (Ye et al. 1997).

Non-pasteurized soil or soil-based rooting media are being used to raise eucalypts in nurseries in south China. It is unclear whether these practices are optimal for the growth of eucalypt plants or the development of ectomycorrhizal associations. Therefore, there is a need to optimize nursery practices to meet the demand for high quality seedlings and clonal lines of Eucalyptus urophylla and hybrids, for outplanting in the region. Inoculation with spores of ectomycorrhizal fungi is accepted as desirable due to potential yield benefits in the field. Previous studies have shown that spores of some collections of Scleroderma are vigorous colonizers on E. urophylla seedlings. These could be used in inoculation programs in China if nursery conditions were suitable for ectomycorrhizal development and the fungi persisted in the field. Therefore, effects of rooting medium and inoculation with Scleroderma on the growth of E. urophylla were examined in a nursery in south China. A complete randomized block design consisting of five rooting media and eight fungal inoculation (six fungi in non-sterile media, two uninoculated controls either in non-sterile or sterile media) was used. Four types of soil taken from eucalypt plantations in south China were compared to a potting mix with vermiculite, peat and sand. Spores of six Scleroderma taxa were taken from basidiomes collected from under eucalypt plantations in Western Australia and south China. Soil substrates significantly affected the growth of seedlings with large variation in both height and biomass. Seedlings grown in the potting mix were larger (90–220% in shoot height, and 110–420% in total dry weight) than those in soil. Inoculation with spores of Scleroderma to non-sterile soil generally promoted the growth of seedlings and their nutrient acquisition. Inoculation increased the growth of seedlings by 19–55% in shoot height and 25–41% in total biomass, compared to uninoculated plants in each soil. Although the ability t

Greenhouse trials with containerized Eucalyptus globulus and E. urophylla seedlings were made to determine effective inoculum spore densities (Scleroderma cepa from temperate Australia, and S. citrinum from sub-tropical China) and spore storage conditions (fresh spores or spores stored for 5 years at room temperature or at 4 °C; S. albidum, S. areolatum and S. cepa from Western Australia). Inoculation with 106 or 108 spores/seedling increased eucalypt growth by up to 46% in height and 42% in dry weight compared to non-inoculated seedlings at 12 weeks after inoculation. Mycorrhizal formation was poor at 102 spores/seeding. Spores stored at 4 °C for 5 years were as effective in forming mycorrhizas as freshly collected spores when a standard density of 106 spores/seedling was applied. It is recommended that spore densities ≥104 be used for inoculation of containerised eucalypts and that spores be stored at 4 °C until use.

Plantation forestry with exotic trees in south China needs compatible symbionts to improve the growth of seedlings in nurseries and to enhance establishment and growth in the field. Scleroderma, a potentially suitable symbiont for inoculation, is not being used in containerized nurseries in the region due to poor knowledge of its host range. The ability of 15 collections of Scleroderma, nine from Australia and six from Asia, to colonize and promote growth of four important exotic plantation trees (Eucalyptus globulus Labill., Eucalyptus urophylla ST Blake, Pinus elliottii Engl., and Pinus radiata D. Don) was examined in a nursery potting mix. There was generally low host specificity of Scleroderma between tree genera. At 12 weeks after inoculation, 13 to 14 of the 15 spore collections formed ectomycorrhizas on seedlings of eucalypts or pines. The extent of colonization differed between spore treatments with two or four collections forming abundant mycorrhizas (>50% fine roots colonized) on E. globulus or E. urophylla, respectively, and three or five on P. radiata or P. elliottii, respectively. Three collections from Australia strongly colonized all hosts resulting in 26 to 100% of short roots being colonized. Chinese Scleroderma collections resulted in fewer mycorrhizas on eucalypts than on pines. Inoculation stimulated the growth (shoot height and dry weight) of eucalypt and pine seedlings by up to 105% where Scleroderma mycorrhizas developed. The results suggest that there is a need to source Scleroderma from outside China for inoculating eucalypts in Chinese nurseries whereas Chinese collections of Scleroderma could be used in pine nurseries. Further screening of Australian and Chinese Scleroderma should be performed in Chinese nurseries and in the field before final commercial decisions are made.

Pterocarpus indicus (Leguminosae: Papilionoideae) is one of the commercial tree legume species that dominate South-East Asia and some Pacific regions (Soerianegara & Lemmens 1993). This species has many common names, such as angsana or sena in Malaysia and Singapore, sonokembang in Indonesia and narra in the Philippines (Corner 1988). Pterocarpus indicus grows on a variety of soil types from fertile agricultural soil to rocky soil, along inundated river banks, swamps and lagoons (Allen & Allen 1981, Corner 1988). It has the status of national tree in the Philippines and has been identified by the Forest Research Institute Malaysia (FRIM) as one of the potential ‘millennium tree’ species for forest plantation establishment in Peninsular Malaysia because of its fast growth and other desirable characteristics (Appanah & Wienland 1993, Lok 1996). However, growth data are restricted to early reports from reforestation projects in the Philippines (Sardina 1951, Assidao & Cerna 1960) and individual amenity trees in Singapore (Wong 1982). Pterocarpus indicus is now mostly grown as an ornamental tree and is relatively rare in forests in South-East Asia due to extensive selective logging (Soerianegara & Lemmens 1993). The timber of P. indicus is classified as light hardwood and is used for light to heavy construction, joists, beams and interior finishes. The wood, which is commonly traded as rosewood, has beautiful distinct growth rings and is ranked among the finest for furniture making, high grade cabinet work, carvings, decorative flooring and musical instruments (Appanah & Weinland 1993, Soerianegara & Lemmens 1993). Legumes, especially tropical woody species, are important for maintaining ecosystem fertility and are used in soil stabilization and revegetation programmes (Langkamp et al. 1979, Dreyfus & Dommergues 1981). Pterocarpus species are reported to nodulate with Rhizobium and Bradyrhizobium in the field but little is known about the specificity, symbiotic relation

Oilseed rape (Brassica napus) is sensitive to low boron (B) supply, and its growth response to B may be influenced by soil temperature. To test the relationship between B and temperature, oilseed rape (cv. Hyola 42) seedlings were grown at 10°C (low) root zone temperature (RZT) with B supply from deficient to adequate B levels until growth of low B plants just began to slow down. Half of the pots were then transferred to 20°C (warm) RZT for 11 days before they were moved back to 10°C RZT for the final 4 days. Both plant dry mass and B uptake increased after plants were exposed to warm RZT. However, plant B deficiency was exacerbated by warm RZT in low B plants because of increased relative growth rate and shoot–root ratio without a commensurate increase in B uptake rate. It is concluded that RZT above the critical threshold for chilling injury in oilseed rape can nevertheless affect the incidence of B deficiency by altering shoot–root ratio and hence the balance between shoot B demand and B uptake.

Coniothyrium zuluense causes a serious canker disease of Eucalyptus in various parts of the world. Very little is known regarding the taxonomy of this asexual fungus, which was provided with a name based solely on morphological characteristics. In this study we consider the phylogenetic position of C. zuluense using DNA-based techniques. Distance analysis using 18S and ITS regions revealed extensive sequence divergence relative to the type species of Coniothyrium, C. palmarum and species of Paraconiothyrium. Coniothyrium zuluense was shown to be an anamorph species of Mycosphaerella, a genus that includes a wide range of Eucalyptus leaf and stem pathogens. Within Mycosphaerella it clustered with taxa having pigmented, verruculose, aseptate conidia that proliferate percurrently and sympodially from pigmented conidiogenous cells arranged in conidiomata that vary from being pycnidial to acervular. The genus Colletogloeopsis is emended to include species with pycnidial conidiomata, and the new combination Colletogloeopsis zuluense is proposed. This is also the first report of the pathogen from China where it is associated with stem cankers on Eucalyptus urophylla.

Eucalypts are highly favoured plantation species as they are fast growing and easy to cultivate. The timber is an important source of fibre to the international pulp and paper industry. Plantation forestry in China is rapidly expanding, and now exceeds more than 1.3 million ha, mostly Eucalyptus urophylla, E. grandis and their hybrids (Minsheng 2003, Qi 2003). A number of foliar plant pathogens have been reported to impact on yields in plantations of eucalypt species in tropical Asia including Mycosphaerella spp., Phaeophleospora spp., Cryptosporiopsis spp. and Cylindrocladium spp. (Old et al. 2003b, Barber 2004). In this study we report, for the first time, the presence of Phaeophleospora destructans in China. Six Phaeophleospora species are known to cause disease on eucalypts; P. delegatensis, P. lilianiae, P. epicoccoides, P. eucalypti and P. destructans and the newly described P. toledana (Crous 1998, Crous et al. 2004). Of these, P. delegatensis, P. lilianiae and P. toledana are limited in their distribution, while P. epicoccoides, P. eucalypti and P. destructans are considered major eucalypt pathogens (Wingfield et al. 1996, Park et al. 2000, Hood et al. 2002).

Alternaria blight, caused by Alternaria alternata, is a recent and serious disease of commercially grown Paulownia trees in Western Australia. This study investigated the effect of temperature, humidity, wounding and leaf age on lesion development. Temperature had a significant effect on infection, with lesion development and expansion observed to increase from 15-25°C, declining between 30 and 37°C. Relative humidity (RH) also influenced infection with limited lesion development observed at ≤92% RH whereas incubation at 98 and 100% RH resulted in large lesions. The optimum conditions determined for lesion development were incubation at 25-30°C with 98-100% RH. Wounded leaf tissue was significantly more susceptible to infection than non-wounded leaf tissue and senescent leaves were more susceptible than newly emerged leaves. Variation in pathogenicity was also observed on senescent leaves infected with different pathotypes of A. alternata. These results appear to correlate well with field observations and may be useful in the control, management and forecast strategies for Alternaria blight in Australian Paulownia plantations. ©

The importance of micronutrients in sustainable crop production is usually linked to the focus on high yields and increased cropping intensity on existing arable lands for feeding the ever-increasing world population. However, micronutrient exports from cropping systems have often been neglected, while fertiliser strategies for high yields are largely based on NPK, particularly in developing countries. Land degradation such as organic matter loss and soil acidification has added another layer of complexity of managing micronutrients in cropping systems. Micronutrient fertilizer strategies must embrace changes in farming systems and land uses, including the shifts to no-till and water-saving rice production. In addition to effects of soil organic matter and soil acidification, micronutrient availability in the rooting zone is likely to be further influenced by erratic rainfall patterns and drought associated with climate change in the future. Solutions to these challenges will lie with well-designed agronomic measures such as regular replenishment of micronutrients through fertiliser inputs and crop residue management. Breeding traits of micronutrient efficiencies (including uptake and utilisation) into high yielding varieties of existing crops may be one of the long-term options for not only minimising crop failures, but enhancing crop quality such as micronutrient density in grain/seeds which are staple foods of populations who mainly consume plant-based food.

Phaeophleospora destructans was first described in 1996 from north Sumatra, Indonesia, where it causes a severe leaf and shoot blight on Eucalyptus grandis in nurseries and young plantations. Since then it has been reported in nurseries and plantations in Vietnam and Thailand, with its host range extending to include E. camaldulensis and E. urophylla, Phaeophleospora destructans has also been reported from native E. urophylla in East Timor, presenting the possibility it may be native pathogen there. During surveys of nurseries in Southern China in 2004/2005, P. destructans was found to be widespread, including areas where there are no plantations, strongly suggesting that the pathogen is being transported throughout the region on infected germplasm. The ITS, beta-tubulin and elongation factor I-alpha gene regions of three P. destructans isolates from each of Sumatra, Vietnam, Thailand and Southern China were sequenced and found to be identical. Microsatellite markers were developed for p, destructans using the FIASCO (fast isolation by AFLP of sequences containing repeats) enrichment technique and although 7 repeat-rich gene regions were identified, none of them were variable among the representative isolates tested, It appears that P. destructans in nurseries and plantations in Asia has very low genetic diversity. This could suggest a recent host jump from another species onto Eucalyptus or the introduction and movement of a very limited gene pool from Sumatra to the rest of Asia. Phaeophleospora destructans is currently absent from Australia but its devastating nature could potentially impact on biodiversity of native vegetation and productivity of Eucalyptus plantations and is thus considered a major biosecurity threat. The apparently low genetic diversity of the pathogen should reduce the risk of the impact that it could have on native ecosystems if introduced to Australia, butt plantations of susceptible trees would be at risk. A new initiative has recently bee