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Pigeonpea: a new dryland summer pulse for northern region farming systems
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Pigeonpea is showing promise as a new option for growers seeking a hardy dryland summer pulse crop to fill a gap in their farming systems. Demand is growing for high quality pigeonpea grain for human consumption in India, and among the Indian consumers in Western countries. Last summer, DAF evaluated new experimental pigeonpea lines at four sites across southern and central Qld in GRDC-funded trials. These lines showed high grain yield, quick maturity, short height and short flowering window, and were easy to harvest using existing equipment. Given these encouraging results, efforts to commercialise pigeonpea are continuing
Field experiences and lessons learned from applying participatory system dynamics modelling to sustainable water and agri-food systems
No full textAchieving the objectives of sustainable development in water and agri-food systems requires the utilisation of decision-support tools in stakeholder-driven processes to construct and simulate various scenarios and evaluate the outcomes of associated policy interventions. While it is common practice to involve stakeholders in participatory modelling processes, their comprehensive documentation and the lessons learned remain scarce. In this paper, we share our experience of engaging stakeholders throughout the entire system dynamics modelling process. We draw on two projects implemented in the Volta River Basin, West Africa, to understand the dynamics of water and agri-food systems under changing environmental and socioeconomic conditions. We outline eight key insights and lessons as practical guides derived from each stage of the participatory modelling process, including the pre-workshop stage, problem definition, model conceptualization, simulation model formulation, model testing and verification, and policy design and evaluation. Our findings demonstrate that stakeholders can actively contribute to all phases of the system dynamics modelling process, including parameter estimation, sensitivity analysis, and numerical simulation experiments. However, we encountered notable challenges, including the time-intensive nature of the process, the struggle to reach a consensus on the modelled problem, and the difficulty of translating the conceptual model into a simulation model using stock and flow diagrams – all of which were addressed through a structured facilitation process. While the projects were anchored in the specific context of West Africa, the key lessons and insights highlighted have broader significance, particularly for researchers employing PSDM in regions characterised by multifaceted human-environmental systems and where stakeholder involvement is crucial for holistic understanding and effective policy interventions. This paper contributes practical guidance for future efforts with participatory modelling, particularly in regions worldwide grappling with sustainable development challenges in water and agri-food systems, and where stakeholder involvement is crucial for holistic understanding of the multiple challenges and for designing effective policy interventions
Ecological factors influencing invasive predator survival and movement: insights from a continental-scale study of feral cats in Australia
Get PDFFeral cats (Felis catus) pose a significant global threat to biodiversity, primarily through predation, disease and competition. A key gap in parameterizing models for improving management decisions for feral cat control relates to factors that drive feral cat survival and movement in the wild. Our study objective was to conduct the first continental-scale analysis of survival rates and displacement distances for feral cats. We collated data on 528 feral cats from telemetry studies in naturally-vegetated landscapes across Australia. Using Cox-proportional hazards models, we investigated the effects of sex, presence of larger predators (dingoes, Canis familiaris and introduced foxes, Vulpes vulpes), presence of introduced prey (rabbits, Oryctolagus cuniculus), body mass, landscape productivity and feral cat density on feral cat survival. We also analysed the effects of sex, body mass and landscape productivity on feral cat displacement using linear mixed model analysis. Feral cat survival was positively associated with presence of dingoes and increasing body mass, whereas there was no clear association between feral cat survival and sex, presence of rabbits, or cat density. Presence of foxes had a strong negative effect on feral cat survival, but the hazard ratio was associated with considerable uncertainty. Net displacement of male feral cats was nearly two times further than that of females, and the proportion of feral cats making long-distance movements was greater in landscapes with low productivity. Increasing body mass of feral cats was positively related to net displacement, with heavier cats moving further. Analysis of metadata from telemetry studies can provide valuable insights into wildlife survival rates and movement behaviour. Our findings will help inform the development of effective management strategies and improve feral cat management for biodiversity conservation
Broad-scale genetic population connectivity in the Moreton Bay Bug (Thenus australiensis) on Australia’s east coast
Get PDFUnderstanding population connectivity helps inform resource and conservation managers about appropriate boundaries for management units. However, for many species facing recent increases in fishing or environmental pressure, accurate information on population structure is lacking. Reef Bugs (Thenus australiensis), commonly known as Moreton Bay Bugs, are iconic shovel-nosed lobsters in northern Australia and an increasingly important fisheries resource. Around 80% of landings occur in the Queensland East Coast Otter Trawl Fishery (ECOTF) where the first stock assessment of the species is underway. However, knowledge about population structure to inform stock assessment is lacking. We used genome complexity reduction-based sequencing to characterise high-quality Single Nucleotide Polymorphisms (SNPs) used to evaluate population structure among three management zones of the ECOTF. Post-filtering, a total of 3,031 SNPs were used to infer no genetic differences among locations indicating strong genetic population connectivity. The presence of a single panmictic population was further supported by cluster and kinship analyses. Broad-scale genetic connectivity likely results from pelagic larval dispersal due to limited adult movements. Findings of high gene flow among connected populations indicate a single biological stock of T. australiensis on Australia’s east coast and will inform future fisheries management initiatives
First Isolation of Japanese Encephalitis Virus Genotype IV from Mosquitoes in Australia
Get PDFIntroduction: Widespread transmission of Japanese encephalitis virus (JEV) genotype four (GIV) occurred across mainland Australia in 2022. This resulted in forty-five human cases, including seven deaths, and the identification of JEV infection in over 80 commercial piggeries. Materials and Methods: We collected mosquitoes which were trapped using CO2-baited light traps deployed near piggeries reporting disease or in regions linked to human cases in the Wide Bay region in the state of Queensland. Mosquitoes from four traps yielded JEV RNA by real-time RT-PCR. Pools containing RNA positive mosquitoes were inoculated onto mosquito cell monolayers. Discussion: A single isolate of JEV was obtained from a pool of mixed mosquito species. Near whole genome sequencing and phylogenetic analysis of the JEV isolate demonstrated its high genomic relatedness with JEV GIV pig sequences sampled from Queensland and the state of New South Wales in 2022. Conclusion: We report the first isolation of JEV GIV from mosquitoes collected in Australia. With only a few JEV GIV isolates available globally, the isolate we report will be essential for future research of JEV host interactions, evolution and disease markers, and development of effective therapies, vaccines, diagnostic assays, and mosquito control strategies
Fusarium wilt constrains mungbean yield due to reduction in source availability
No full textMungbean [Vigna radiata (L.) R. Wilczek var. radiata] is an important source of plant protein for consumers and a high-value export crop for growers across Asia, Australia, and Africa. However, many commercial cultivars are highly vulnerable to biotic stresses, which rapidly reduces yield within the season. Fusarium oxysporum is a soil-borne pathogen that is a growing concern for mungbean growers globally. This pathogen causes Fusarium wilt by infecting the root system of the plant resulting in devastating yield reductions. To understand the impact of Fusarium on mungbean development and productivity and to identify tolerant genotypes, a panel of 23 diverse accessions were studied. Field trials conducted in 2016 and 2021 in Warwick, Queensland, Australia under rainfed conditions investigated the variation in phenology, canopy and yield component traits under disease and disease-free conditions. Analyses revealed a high degree of genetic variation for all traits. By comparing the performance of these traits across these two environments, we identified key traits that underpin yield under disease and disease-free conditions. Aboveground biomass components at 50% flowering were identified as significant drivers of yield development under disease-free conditions and when impacted by Fusarium resulted in up to 96% yield reduction. Additionally, eight genotypes were identified to be tolerant to Fusarium. These genotypes were found to display differing phenological and morphological behaviours, thereby demonstrating the potential to breed for tolerant lines with a range of diverse trait variations. The identification of tolerant genotypes that sustain yield under disease pressure may be exploited in crop improvement programs
Mycorrhizal fungi increase plant nutrient uptake, aggregate stability and microbial biomass in the clay soil
No full textArbuscular mycorrhizal fungi (AMF) are beneficial soil organisms that can form symbiotic associations with the host plant roots. Mycorrhizal symbiosis between plant root and fungi can influence plant diversity and ecosystem productivity. However, the impacts of AMF frequently documented in the loamy to sandy soil, whereas it has no precise mechanism of influencing plant productivity, macronutrient uptake, and aggregation in a clay soil. A pot experiment was carried out to investigate the impact of AMF on plant growth, nutrient uptake and soil aggregation in a clay soil of Bangladesh. Okra (Abelmoschus esculentus L.) was cultivated over 105 days with AMF and without AMF (NAMF) with 5 replications. Plant productivity, nutrient uptake, soil organic carbon (SOC), microbial biomass carbon (MBC), aggregate stability (MWD), and glomalin-related soil protein (GRSP) were measured after 105 days. Results showed that the plant productivity and nutrient availability in soil and their subsequent uptake in AMF were significantly higher compared to the NAMF treatment (p < 0.01). We observed 17% increase in aggregate stability (measured as mean weight diameter) and 28% increase in organic carbon in AMF inoculated soil compared to NAMF. The microbial biomass carbon and GRSP were significantly higher in the AMF than NAMF treatment (p < 0.01). The findings highlight that AMF introduction can be a promising tool for improving plant production and soil condition in the clay soil instead of conventional farming system
Molecular characterisation of a novel sadwavirus infecting cattleya orchids in Australia
Get PDFThe complete genome sequence of a novel sadwavirus infecting cattleya orchids in South East Queensland is described. Isometric virions of c. 27 nm diameter were observed in sap extracts viewed under a transmission electron microscope, and the genome sequence of this virus was determined by high-throughput sequencing. The viral genome consists of two RNA components, 5,910 and 4,435 nucleotides (nt) in length, each encoding a long polyprotein, with predicted cleavage sites at H/Y, E/G, Q/S, and Q/G for the RNA1 and T/G for the RNA2 translation products, respectively. RNA2 has an additional small ORF of 684 nt near the 3ʹ untranslated region. Phylogenetic analysis based on an amino acid sequence alignment of the Pro-Pol region suggested that this virus is most closely related to pineapple secovirus A, a member of the subgenus Cholivirus, but warrants classification as a member of a new species because it exhibited no more than 64% amino acid identity in pairwise sequence comparisons. Because of the prominent purple ringspots that were observed on the leaves of some of the plants, we propose the name “cattleya purple ringspot virus” for this virus (suggested species name: “Sadwavirus cattleyacola”)
A chromosome-level genome of mango exclusively from long-read sequence data
Get PDFImprovements in long-read sequencing techniques have greatly accelerated plant genome sequencing. Current de novo assemblies are routinely achieved by assembling long-read sequence data into contigs that are assembled to chromosome level by chromatin conformation capture. We report here a chromosome-level mango genome using only PacBio high-fidelity (HiFi) long reads. HiFi reads at high coverage (204x) resulted in the assembly of 17 chromosomes, each as a single contig with telomeres at both ends. The remaining three chromosomes were represented each by two contigs, with telomeres at one end and ribosomal repeats at the other end. Analyzing contig ends allowed them to be paired and linked to generate the remaining three complete chromosomes, telomere-to-telomere but with ribosomal repeats of uncertain length. The assembled genome was 365 Mb with 100% completeness as assessed by Benchmarking Universal Single-Copy Orthologs analysis. The haplotypes assembled demonstrated extensive structural differences. This approach using very high genome coverage may be useful for assembling high-quality genomes for many other plants
