African mahogany (Khaya senegalensis) plantations in Australia - status, needs and progress

The Australian African mahogany estate comprises over 12,000 ha of industrial plantations, farm-forestry plots and trials, virtually all derived from Africa-sourced wild seed. However, the better trees have given high-value products such as veneers, high-grade boards and award-winning furniture. Collaborative conservation and improvement by the Northern Territory (NT) and Queensland governments since 2000 realised seed orchards, hedge gardens and genetic tests revealing promising clones and families. Private sector R&D since the mid 2000s includes silvicultural-management and wood studies, participatory testing of government material and establishing over 90 African provenances and many single-tree seedlots in multisite provenance and family trials. Recent, mainly public sector research included a 5-agency project of 2009-12 resulting in advanced propagation technologies and greater knowledge of biology, wood properties and processing. Operational priority in the short term should focus on developing seed production areas and ‘rolling front’ clonal seed orchards. R&D priorities should include: developing and implementing a collaborative improvement strategy based on pooled resources; developing non-destructive evaluation of select-tree wood properties, micropropagation (including field testing of material from this source) to ‘industry ready’ and a select-tree index; optimising seed production in orchards; advancing controlled pollination techniques; and maximising benefits from the progeny, clone and provenance trials. Australia leads the world in improvement and ex situ conservation of African mahogany based on the governments’ 13-year program and more recent industry inputs such that accumulated genetic resources total over 120 provenances and many families from 15 of the 19 African countries of its range. Having built valuable genetic resources, expertise, technologies and knowledge, the species is almost ‘industry ready’. The industry will benefit if it exploits the comparative advantage these assets provide. However the status of much of the diverse germplasm introduced since the mid 2000s is uncertain due to changes in ownership. Further, recent reductions of government investment in forestry R&D will be detrimental unless the industry fills the funding gaps. Expansion and sustainability of the embryonic industry must capitalise on past and current R&D, while initiating and sustaining critical new work through all-stakeholder collaboration

Conducting research in individual patients: lessons learnt from two series of N-of-1 trials

BACKGROUND: Double-blind randomised N-of-1 trials (N-of-1 trials) may help with decisions concerning treatment when there is doubt regarding the effectiveness and suitability of medication for individual patients. The patient is his or her own control, and receives the experimental and the control treatment during several periods of time in random order. Reports of N-of-1 trials are still relatively scarce, and the research methodology is not as firmly established as that of RCTs. Recently, we have conducted two series of N-of-1 trials in general practice. Before, during, and after data-collection, difficulties regarding outcome assessment, analysis of the results, the withdrawal of patients, and the follow-up had to be dealt with. These difficulties are described and our solutions are discussed. DISCUSSION: To prevent or anticipate difficulties in N-of-1 trials, we argue that that it is important to individualise the outcome measures, and to carefully consider the objective, type of randomisation and the analysis. It is recommended to use the same dosages and dosage forms that the patient used before the trial, to start the trial with a run-in period, to formulate both general and individualised decision rules regarding the efficacy of treatment, to adjust treatment policies immediately after the trial, and to provide adequate instructions and support if treatment is adjusted. SUMMARY: Because of the specific characteristics of N-of-1 trials it is difficult to formulate general 'how to do it' guidelines for designing N-of-1 trials. However, when the design of each N-of-1 trial is tailored to the specific characteristics of each individual patient and the underlying medical problem, most difficulties in N-of-1 trials can be prevented or overcome. In this way, N-of-1 trials may be of help when deciding on drug treatment for individual patients

Prospects of eucalypt species, including interspecific hybrids from South Africa, for hardwood plantations in marginal subtropical environments in Queensland, Australia

In Australia, there has been rapid expansion in recent years of commercial plantations of hardwood timber species, especially of Eucalyptus and Corymbia. In tropical and sub-tropical Queensland the land most likely to be readily available for this planting is in the marginal 650-1000 MAR zone where, potentially, millions of hectares could be planted on cleared land. Optimal forestry plantation practice requires matching of taxa (species-provenances-hybrids) and sites. However, experiment-based identification of taxa with commercial potential has not been accomplished for many regions in this rainfall zone of Queensland. In Brazil, China and South Africa, large viable plantation estates have been developed on marginal lands through use of hardy, high-yielding interspecific eucalypt hybrids (Eldridge et al. 1993). Eucalypt hybrid breeding is in its infancy in Queensland so the potential exists to accelerate the identification of superior hybrids through introduction and testing of material developed elsewhere. Based on this overseas experience, bulk seedlots of selected eucalypt hybrids have been introduced, in strict accordance with quarantine requirements, and are now being tested against Eucalyptus and Corymbia species and provenance controls in key regions of Queensland and northern NSW. This paper presents two-year results for three trials in sub-tropical Queensland, indicates the taxa with fastest early growth and considers the potential and suitability of several eucalypt hybrids (seedlings) to marginal sites in Queensland. Southern African Forestry Journal No.190 2001: 89-9

Natural inter-subgeneric hybridization between Eucalyptus acmenoides Schauer and Eucalyptus cloeziana F. Muell (Myrtaceae) in southeast Queensland

Eucalyptus acmenoides Schauer (white mahogany) and E. cloeziana F. Muell (Gympie messmate) are largely allopatric but have several sympatric populations across their range in eastern Queensland, Australia. In this study, verification of interspecific hybridization at the site of one such sympatric population was carried out using morphological and molecular (nuclear and cytoplasmic) characters. Capsule morphology was intermediate in hybrids, particularly with respect to the number of valves per capsule. Hybridization was found to occur in both directions with maternal inheritance of a taxon-specific polymorphism in the inverted repeat of the J(LA) region of the chloroplast genome. However, E. acmenoides acted as the maternal parent in all but one hybrid individual, possibly due to protandry of flowering. High levels of polymorphism in microsatellite loci existed between E. acmenoides and E. cloeziana in the hybrid zone. Formation of hybrids was most likely limited to F-1 mating and was restricted in both numbers and dispersal within the hybrid zone. Current taxonomy places E. cloeziana and E. aemenoides into different subgenera, Idiogenes and Monocalyptus respectively. This is significant as it is the only example of natural hybridization between subgenera within the Eucalyptus genus, suggesting that the taxonomic classification of E. acmenoides and E. cloeziana should be investigated further

Cellular stages of root formation, root system quality and survival of Pinus elliottii var. elliottii x P. caribaea var. hondurensis cuttings in different temperature environments

Time to first root in cuttings varies under different environmental conditions and understanding these differences is critical for optimizing propagation of commercial forestry species. Temperature environment (15, 25, 30 or 35 ± 2°C) had no effect on the cellular stages in root formation of the Slash × Caribbean Pine hybrid over 16 weeks as determined by histology. Initially callus cells formed in the cortex, then tracheids developed and formed primordia leading to external roots. However, speed of development followed a growth curve with the fastest development occurring at 25°C and slowest at 15°C with rooting percentages at week 12 of 80 and 0% respectively. Cutting survival was good in the three cooler temperature regimes (gt;80%) but reduced to 59% at 35°C. Root formation appeared to be dependant on the initiation of tracheids because all un-rooted cuttings had callus tissue but no tracheids, irrespective of temperature treatment and clone