Lucerne biology and genetic improvement - an analysis of past activities and future goals in Australia

Breeding methodologies for cultivated lucerne (Medicago sativa L.), an autotetraploid, have changed little over the last 50 years, with reliance on polycross methods and recurrent phenotypic selection. There has been, however, an increase in our understanding of lucerne biology, in particular the genetic relationships between members of the M. sativa complex, as deduced by DNA analysis. Also, the differences in breeding behaviour and vigour of diploids versus autotetraploids, and the underlying genetic causes, are discussed in relation to lucerne improvement. Medicago falcata, a member of the M. sativa complex, has contributed substantially to lucerne improvement in North America, and its diverse genetics would appear to have been under-utilised in Australian programs over the last two decades, despite the reduced need for tolerance to freezing injury in Australian environments. Breeding of lucerne in Australia only commenced on a large scale in 1977, driven by an urgent need to introgress aphid resistance into adapted backgrounds. The release in the early 1980s of lucernes with multiple pest and disease resistance (aphids, Phytophthora, Colletotrichum) had a significant effect on increasing lucerne productivity and persistence in eastern Australia, with yield increases under high disease pressure of up to 300% being recorded over the predominant Australian cultivar, up to 1977, Hunter River. Since that period, irrigated lucerne yields have plateaued, highlighting the need to identify breeding objectives, technologies, and the germplasm that will create new opportunities for increasing performance. This review discusses major goals for lucerne improvement programs in Australia, and provides indications of the germplasm sources and technologies that are likely to deliver the desired outcomes.

Rehabilitation outcomes for brain injured patients in Australia: functional status, length of stay and discharge destination

This study describes the rehabilitation length of stay (LOS), discharge destination and discharge functional status of 149 patients admitted with traumatic brain injury (TBI) to an Australian hospital over a 5-year period. Hospital charts of patients admitted between 1993-1998 were reviewed. Average LOS over the 5-year time period was 61.8 days and only decreased nominally over this time. Longer LOS was predicted by lower admission motor FIM scores and presence of comorbidities. Mean admission and discharge motor FIM scores were 58 and 79, which represented a gain of 21 points. Higher discharge motor FIM scores were predicted by higher admission motor FIM scores and younger age. FIM gain was predicted by cognitive status and age. Most patients, 88%, were discharged back to the community, with 30% changing their living setting or situation. Changing living status was predicted by living alone and having poorer functional status on admission.

A typology of community opportunity and vulnerability in metropolitan Australia

A multivariate model using hierarchical clustering and discriminant analysis is used to identify clusters of community opportunity and community vulnerability across Australia's mega metropolitan regions, Variables used in the model measure aspects of structural economic change, occupational change, human capital, income, unemployment, family/household disadvantage, and housing stress. A nine-cluster solution is used to categorise communities across metropolitan space. Significant between-city variations in the incidence of these clusters of opportunity and vulnerability are apparent, suggesting the emergence of marked differentiation between Australia's mega metropolitan regions in their adjustments to changing economic and social conditions. JEL classification: C49, R11, R12.

A low-latitude bloom of the surf-zone diatom, Anaulus australis (Centrales, Bacillariophyta) on the coast of Southern Queensland (Australia)

A novel bloom of the surf diatom Anaulus australis Drebes et Schultz was observed in subtropical waters off Surfers' Paradise, Queensland, Australia (27 degrees 55'S; 153 degrees 23'E) in early May 2000. This is the lowest latitude in which an Anaulus australis surf diatom bloom has been reported. Nitrogen stable isotope analysis of surf diatoms may indicate anthropogenic nutrient inputs in this environment.

Field test of a model of migration of moths (Lepidoptera : Noctuidae) in inland Australia

A migration of Helicoverpa punctigera (Wallengren), Heliothis punctifera (Walker) and Agrotis munda Walker was tracked from Cameron Corner (29degrees00'S, 141degrees00'E) in inland Australia to the Wilcannia region, approximately 400 km to the south-east. A relatively isolated source population was located using a distribution model to predict winter breeding, and confirmed by surveys using sweep netting for larvae. When a synoptic weather pattern likely to produce suitable conditions for migration developed, moths were trapped in the source region. The next morning a simulation model of migration using wind-field data generated by a numerical weather-prediction model was run. Surveys using sweep netting for larvae, trapping and flush counts were then conducted in and around the predicted moth fallout area, approximately 400 km to the south-east. Pollen carried on the probosces of moths caught in this area was compared with that on moths caught in the source area. The survey data and pollen comparisons provided evidence that migration had occurred, and that the migration model gave accurate estimation of the fallout region. The ecological and economic implications of such migrations are discussed.

Wind-blown mosquitoes and introduction of Japanese encephalitis into Australia

Backtrack simulation analysis indicates that wind-blown mosquitoes could have traveled from New Guinea to Australia, potentially introducing Japanese encephalitis virus. Large incursions of the virus in 1995 and 1998 were linked with low-pressure systems that sustained strong northerly winds from New Guinea to the Cape York Peninsula.

Reproductive dynamics of endeavour prawns, Metapenaeus endeavouri and M-ensis, in Albatross Bay, Gulf of Carpentaria, Australia

The spawning patterns of two penaeid prawns, Metapenaeus endeavouri (Schmitt) and M. ensis (De Haan), were examined from data collected at 45 stations between March 1986 and March 1992. An index of population fecundity based on the abundance, proportion and fecundity of sexually mature females was used as a measure of spawning output of the prawn stock. The population fecundity index for M. ensis was higher than that for M. endeavouri. The monthly population fecundity index for M. endeavouri varied markedly among years, while that for M. ensis was consistent among years. Spawning of M. endeavouri occurred year-round, while that of M. ensis was concentrated mainly in spring (September to November). For M. endeavouri, a minor spawning, derived from a relatively small number of summer spawners, occurred in the 20 to 30 m offshore waters in summer. In early summer (after May), the major spawning group consisted of large females from the winter-spawning cohort, and the spawning area shifted to depths of 30 to 60 m. In winter (July), the major spawning, derived from the winter-spawning cohort, occurred at depths of 20 to 40 m. For M. ensis, the major spawning, derived from the spring-spawning cohort, was observed in depths < 50 m and was concentrated particularly in inshore waters ( 50 m). These results suggest that mature female M. endeavouri and M. ensis move offshore (>40 m) by May and July, respectively, and return to shallow waters (

Comparative phylogeography of two open forest frogs from eastern Australia

We investigated the phylogeography of two closely related Australian frog species from open forest habitats, Limnodynastes tasmaniensis and L. peronii, using mitochondrial ND4 sequence data. Comparison of our results with previous work on Litoria fallax allowed us to test the generality of phylogeographic patterns among non-rainforest anurans along the east coast of Australia. In general, there was no strong evidence for congruence between overall patterns of genetic structure in the three species. However, phylogenetic breaks congruent with the position of the Burdekin Gap were detected at some level in all species. As previously noted for closed forest taxa, this area of dry habitat appears to have been an important influence on the evolution of several open forest taxa. There were broad geographic similarities in the phylogenetic structuring of southern populations of L. peronii and L. tasmaniensis. Contrarily, although the McPherson Range has previously been noted to coincide geographically with a major mtDNA phylogenetic break in Litoria fallax this pattern is not apparent in L. peronii or L. tasmaniensis. It appears that major phylogeographic splits within L. peronii and L. tasmaniensis may predate the Quaternary. We conclude that phylogeographies of open forest frogs are complex and more difficult to predict than for rainforest taxa, mainly due to an absence of palaeomodels for historical distributions of non-rainforest habitats. (C) 2001 The Linnean Society of London.