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GWAS, KASP-SNP markers and haplotype-based pre-breeding for improving yield potential on sodic-dispersive soils in wheat (Triticum aestivum L.)
No full textSodic-dispersive soils have multiple subsoil constraints including poor soil structure, high pH ( \u3e 7), salinity, high subsoil toxic elemental ion concentration (boron, aluminium), and water-logging, affecting growth and development in wheat. Dispersive soils are common in the Australian agricultural landscapes and wheat growing regions around the world. Recent estimates show about 8-10 % soils in Western Australian grain belt to be dispersive leading to heavy losses in production and grower income. Tolerance is required at all developmental stages to enhance wheat yield potential on such soils. An in-depth investigation of genome wide associations was conducted using a two-year field phenotypic data of 206 diverse. Focused Identification of Germplasm Strategy (FIGS) wheat lines from different sodic and non-sodic plots and the exome targeted genotyping by sequencing (tGBS) assay. A total of 39 quantitative trait SNPs (QTSs), including 18 haplotypes were identified on chromosome 1A, 1B, 1D, 2A, 2B, 2D, 3A, 3B, 5A, 5D, 6B, 7A, 7B, 7D for yield and yield components’ tolerance to soil sodicity. Among these, three QTSs had common associations for multiple traits, indicating pleiotropism and four QTSs had close associations for multiple traits, within 32.38 Mb. The overlapping metal ion binding (Mn, Ca, Zn and Al) and photosynthesis genes, and transcription factors (PHD-, Dof-, HTH myb-, BHLH-, PDZ_6-domain) identified are known to be highly regulated during germination, maximum stem elongation, anthesis, and grain development stages. The homozygous/biallelic SNPs were identified for yield and crop establishment/plants m-2. These SNPs correspond to HTH myb-type and BHLH transcription factors, brassinosteroid signaling pathway, kinase activity, ATP, and chitin binding activity (Published, 10.1007/s00122-021-04021-8). Further, the variants (SNPs and InDel) identified are functionally annotated and characterized using snpEff pipeline. The characterized variants are analyzed for their effects on protein based on type of impact (high, low, moderate and modifier) using the wheat genome binary database. The functional SNPs having higher phenotypic variation and allele frequency greater than five percent is now being converted to KASP-SNP markers and the rapid KASP-SNP assay will be validated in FIGS and double haploid populations. These resources are valuable in haplotype-based breeding and genome editing to improve yield potential on sodic-dispersive soils
Improving design-based estimates of biological data collected from a restricted spatio-temporal access point survey of recreational fishers
No full textAccurate and precise estimates of recreational harvest are required where there are formal catch allocations between commercial and recreational sectors. Yet they are challenging to obtain without appropriately designed surveys, especially in the recreational sector, which often require complex survey designs. Estimates of mean body mass are required for recreational fisheries when converting catch by numbers to catch by weight and should account for pseudoreplication to truly represent the characteristics of the data. However, methods for determining mean mass from recreational fishing surveys are rarely defined, leading to assumptions that an arithmetic mean has been applied, which does not account for pseudoreplication or hierarchical, clustered sampling. This study uses western rock lobster (Panulirus cygnus), commonly targeted by recreational fishers in Western Australia, as a case study to determine a mean mass for retained lobsters using several survey design-based methods. The six-year, restricted spatio-temporal access point survey of boat-based recreational fishers, who target lobsters by trapping or diving, addresses pseudoreplication by aggregating survey data and calculating a weighted mean and uncertainty for non-normally distributed data using nonparametric hierarchical bootstrapping. While we present the mean and confidence intervals for all levels of the survey design, our preferred level is the ultimate sampling unit (lobster) because there are insufficient replicates to conduct nonparametric hierarchical bootstrapping at the primary (day) or secondary (interview) sampling units. For this species, we recommend using a fishing method-based mean rather than an overall mean to capture annual variability in catch and participation and provide an index for determining harvest when catches by number are known for each fishing method. This approach for analyzing recreational fishing data is relevant to other fisheries estimating total recreational harvest from restricted spatio-temporal surveys
Distinctive diets of eutherian predators in Australia
No full textIntroduction of the domestic cat and red fox has devastated Australian native fauna. We synthesized Australian diet analyses to identify traits of prey species in cat, fox and dingo diets, which prey were more frequent or distinctive to the diet of each predator, and quantified dietary overlap. Nearly half (45%) of all Australian terrestrial mammal, bird and reptile species occurred in the diets of one or more predators. Cat and dingo diets overlapped least (0.64 ± 0.27, n = 24 location/time points) and cat diet changed little over 55 years of study. Cats were more likely to have eaten birds, reptiles and small mammals than foxes or dingoes. Dingo diet remained constant over 53 years and constituted the largest mammal, bird and reptile prey species, including more macropods/potoroids, wombats, monotremes and bandicoots/bilbies than cats or foxes. Fox diet had greater overlap with both cats (0.79 ± 0.20, n = 37) and dingoes (0.73 ± 0.21, n = 42), fewer distinctive items (plant material, possums/gliders) and significant spatial and temporal heterogeneity over 69 years, suggesting the opportunity for prey switching (especially of mammal prey) to mitigate competition. Our study reinforced concerns about mesopredator impacts upon scarce/threatened species and the need to control foxes and cats for fauna conservation. However, extensive dietary overlap and opportunism, as well as low incidence of mesopredators in dingo diets, precluded resolution of the debate about possible dingo suppression of foxes and cats
New techniques for underwater video photography of line fishing and their application in shark depredation studies
No full textThere is an increasing need to understand the interaction of marine fauna with line fishing, both recreational and commercial, particularly in regions where shark depredation has become an increasing issue. The dynamic nature of the fishing requires underwater filming techniques that can move with the fishing activity and capture high-resolution footage enabling the identification of fauna species. In the case of shark depredation, the development of deterrent devices specifically designed for use while line fishing will require underwater footage to determine the effectiveness of those devices designed to invoke avoidance behaviours in sharks that approach hooked fish. Two new and inexpensive mounting systems were developed, enabling a range of “action” cameras to be attached to fishing lines to capture underwater footage while line fishing. Using these mounting systems with GoProTM cameras, high-resolution video was obtained during line fishing trials in which the effectiveness of shark deterrents was investigated. The video footage enabled the identification of fish and shark species and recorded any avoidance behaviours of sharks, in response to the presence of deterrents
Lowering the water solubility of phosphorus fertilisers impacts leaching, plant growth and residual soil phosphorus
No full textContext: Leaching of phosphorus (P) from water soluble agricultural fertilisers applied to sandy soil can adversely impact downstream water quality. Less soluble fertilisers may reduce P leaching and increase production. However, repeated application of low water soluble P (LWSP) fertiliser with high citrate soluble P (CSP) has potential to increase P leaching and P accumulation. Methods: We examined the effect of LWSP fertilisers (single superphosphate, SSP; fertilisers low in water soluble P, WSP) on leaching losses in soil with low P retention/low P status; with/without bauxite residue amendment and with/without plants. Key results: On low P retentive soils with a low P status, P leaching was reduced by reducing the WSP of fertiliser. Plants and soil amendment reduced P leaching further, but P loss remained proportional to WSP applied. Under field conditions, a subset of LWSP fertilisers greatly increased pasture dry matter production and increased soil test P values. Soil test P increases were positively correlated to fertiliser citrate soluble P content. Soils already containing at least 80% of the required plant available P did not require a WSP fertiliser to provide early season P. Conclusions: LWSP fertilisers and soil amendment have potential to reduce P leaching in low P retentive soils. Fertiliser formulations targeting reduced WSP and high CSP require attention. Implications: LWSP fertilisers may increase soil P residues reducing future P needs; however, ongoing soil testing is required for assessment of soil P accumulation, requirements and leaching potential
Mind the depth of soil amelioration to surpass the yield gap in Western Australia
No full textIn Western Australia (WA), there is a mean difference of 1.3 t/ha between the actual yield achieved and the water-limited yield potential. We hypothesised deep amelioration of multiple soil constraints would increase yield above the calculated water-limited yield potential for a low-input cropping system. We conducted a series of field experiments in the low rainfall region of WA where soil was ameliorated (i) either by surface application of agricultural lime or (ii) by loosening and incorporating agricultural lime to different depths (up to 45 cm). Surface application of agricultural lime significantly increased yield within 1–7 years of application while combined loosening with lime addition to 45 cm depth (soil re-engineering) at least doubled the grain yield almost immediately and continued to generate the same yield advantage over multiple seasons. Grain yield, in the re-engineering treatment, exceeded the water-limited yield potential by 33─56% under standard agronomic practice
Maximization of fitness by phenological and phenotypic plasticity in range expanding rabbitfishes (Siganidae)
No full textGlobal warming is modifying the phenology, life-history traits and biogeography of species around the world. Evidence of these effects have increased over recent decades; however, we still have a poor understanding of the possible outcomes of their interplay across global climatic gradients, hindering our ability to accurately predict the consequences of climate change in populations and ecosystems. We examined the effect that changes in biogeography can have on the life-history traits of two of the most successful range-extending fish species in the world: the tropical rabbitfishes Siganus fuscescens and Siganus rivulatus. Both species have established abundant populations at higher latitudes in the northern and southern hemispheres and have been identified as important ecological engineers with the potential to alter the community structure of seaweed forests (Laminariales and Fucales) in temperate regions. Life-history trait information from across their global distribution was compiled from the published literature and meta-analyses were conducted to assess changes in (i) the onset and duration of reproductive periods, (ii) size at maturity, (iii) fecundity, (iv) growth rates, (v) maximum body sizes and (vi) longevity in populations at the leading edge of range expansion in relation to sea surface temperature and primary productivity (a common proxy for nutritional resource levels). Populations at highest latitudes had shortened their reproductive periods and reduced growth rates, taking longer to reach sexual maturity and maximum sizes, but compensated this with higher fecundity per length class and longer lifespans than populations in warmer environments. Low primary productivity and temperature in the Mediterranean Sea resulted in lower growth rates and body sizes for S. rivulatus, but also lower length at maturity, increasing life-time reproductive output. The results suggest that plasticity in the phenology and life-history traits of range-expanding species would be important to enhance their fitness in high latitude environments, facilitating their persistence and possible further poleward expansions. Quantifying the magnitude and direction of these responses can improve our understanding and ability to forecast species redistributions and its repercussions in the functioning of temperate ecosystems
DPIRD scientists monitor a tree for biosecurity threats
No full texthttps://library.dpird.wa.gov.au/site_carousel/1049/thumbnail.jp
Chapter 31: Sharks, rays and chimaeras
No full textWildlife Research in Australia: Practical and Applied Methods is a guide to conducting wildlife research in Australia. It provides advice on working through applications to animal ethics committees, presents general operating procedures for a range of wildlife research methods, and details animal welfare considerations for all Australian taxa. Compiled by over 200 researchers with extensive experience in field-based wildlife research, teaching and animal ethics administration, this comprehensive book supports best practice research methods and helps readers navigate the institutional animal care approval process. Wildlife Research in Australia will help foster a national approach to wildlife research methods, and is an invaluable tool for researchers, teachers, students, animal ethics committee members and organisations participating in wildlife research and other activities with wildlife.https://library.dpird.wa.gov.au/books/1032/thumbnail.jp