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The development of multiplex PCR assays for the rapid identification of multiple Saccostrea species, and their practical applications in restoration and aquaculture
Get PDFThe ecology and biology of oysters (Ostreidae) across the tropics is poorly understood. Morphological plasticity and shared characteristics among oysters have resulted in the misidentification of species, creating challenges for understanding basic species-specific biological information that is required for restoration and aquaculture. Genetic barcoding has proven essential for accurate species identification and understanding species geographic ranges. To reduce the costs of molecular species identification we developed multiplex assays using the cytochrome c oxidase subunit I (COI or cox1) barcoding gene for the rapid identification of five species of oysters within the genus Saccostrea that are commonly found in Queensland, Australia: Saccostrea glomerata, Saccostrea lineage B, Saccostrea lineage F, Saccostrea lineage G, and Saccostrea spathulata (lineage J)
Reliability of Nonlinear least square broken stick model in quantifying the effects of temperature and photoperiod on flowering of pigeonpea genotypes (Cajanus cajan (L.) Millsp.)
Get PDFTemperature and photoperiod are two major environmental determinants that affect the flowering time. The information on the effect of temperature and photoperiod on flowering response in pigeonpea is limited and needs updating for new genotypes. The present study aimed to assess the reliability of the Nonlinear least square broken stick model to quantify photothermal ef-fects in pigeonpea (Cajanus cajan(L.) Millsp.) genotypes. Data at 50 % flowering (FL) from pot, field, and temperature-controlled glasshouse experiments under eight sowing dates were analysed using regression models to describe the individual effect of temperature and photoperiod and photothermal models to quantify the combined effect. The critical photoperiod (Pce)and optimum temperature (To)predicted by the Nonlinear broken stick model for 50 % FL ranged from 12.4 -13.4 h and 21.0 -23.5 °C, respectively. The higher Pcereported for extra-early flowering genotype (QPL 1001) indicates that their insensitiveness to a range of photoperiod regimes compared to QPL 941 and ICP 14425 (medium duration). Further, the results also revealed that the time to 50 % FL of genotype QPL 1001 was strongly sensitive to the temperature at sub-optimal range (T To), with flowering being delayed in warmer temperatures. The parameters (Toand Pce) derived from Nonlinear least square broken stick model can be used as a proxy to identify photoperiod insensitivity in pigeopea genotype
FutureBeef: coordinated and collaborative delivery of online information for the northern beef industry
No full textFutureBeef is a collaboration between the Queensland, Northern Territory and Western Australian government departments and Meat & Livestock Australia to provide coordinated delivery of online information for the northern beef industry. Achievements 2018-2022 include: a website with 1222 pages and over 1.7M pageviews and 954,000 visitors; 49 webinars with almost 6900 registrations, over 3000 attendees and 27,200 webinar recording views; 54 eBulletins to 6288 subscribers, with an average open rate of almost 33% and click rate of 8.6%; Facebook, Twitter and Linkedin with 18,821 combined followers and over 85,000 engagements. The FutureBeef website is the key communication tool, while webinars, ebulletins and social media raise awareness and direct users to the website. Improvements to all these tools are critical to enhance user experience
The genome of Citrus australasica reveals disease resistance and other species specific genes
No full textThe finger lime ( Citrus australasica ), one of six Australian endemic citrus species shows a high natural phenotypic diversity and novel characteristics. The wide variation and unique horticultural features have made this lime an attractive candidate for domestication. Currently no haplotype resolved genome is available for this species. Here we present a high quality, haplotype-resolved reference genome for this species using PacBio HiFi and Hi-C sequencing.
Results.
Hifiasm assembly and SALSA scaffolding resulted in a collapsed genome size of 344.2 Mb and 321.1 Mb and 323.2 Mb size for the two haplotypes. The nine pseudochromosomes of the collapsed genome had an N50 of 35.2 Mb, 99.1% genome assembly completeness and 98.9% gene annotation completeness (BUSCO). A total of 41,304 genes were predicted in the nuclear genome. Comparison with C. australis revealed that 13,661 genes in pseudochromosomes were unique in C. australasica . These were mainly involved in plant-pathogen interactions, stress response, cellular metabolic and developmental processes, and signal transduction. The two genomes showed a syntenic arrangement at the chromosome level with large structural rearrangements in some chromosomes. Genetic variation among five C. australasica cultivars was analysed. Genes related to defense, synthesis of volatile compounds and red/yellow coloration were identified in the genome. A major expansion of genes encoding thylakoid curvature proteins was found in the C. australasica genome.
Conclusions
The genome of C. australasica present in this study is of high quality and contiguity. This genome helps deepen our understanding of citrus evolution and reveals disease resistance and quality related genes with potential to accelerate the genetic improvement of citrus
Direct and indirect effects of Basta®, a glufosinate-based herbicide, on banana plantation soil microbial diversity and function
No full textHerbicide applications have doubled over the past 30 years to control weeds, but their use may influence soil microbial communities, which mediate important ecosystem services. Here, we characterised the direct effects of a single application of Basta® (glufosinate), at 1× and 2× the recommended rate (5 and 10 kg product ha−1), as well as the indirect effects of vegetation loss on the diversity and function of soil microbial communities within a banana plantation. A 10-month pre-experimental period using Basta® to remove additional vegetation from half of the experimental area created conditions for assessing the indirect herbicide effects. Direct assessments on soil microbial communities began when the Basta® herbicide treatments were applied to the areas with and without vegetation and continued over multiple time-points, for 56 days. Herbicide treatment had no significant direct impacts on basal, and substrate induced respiration rates, or the potential activities of microbial enzymes as inferred from fluorescein diacetate hydrolysis (FDA) and β-glucosidase assays. Similarly, phylogenetic marker gene sequencing indicated that Basta® application did not significantly influence the diversity of soil bacterial or fungal communities. Indirectly, Basta® had a greater influence on the soil microbial activity and functions by removing understory vegetation cover around banana plants. This suggested that continual use of herbicides to reduce soil vegetation cover under bananas had a greater impact on soil microbial communities than a single application of the herbicide. Furthermore, the presence or absence of vegetation cover, significantly altered the abundance of Fusarium oxysporum, plus an additional eight bacterial and ten fungal taxa. Our results indicated that a single application of glufosinate as Basta® at the recommended or double the recommended rate, did not adversely affect soil microbial communities or their activities in banana plantations directly. However, application of herbicides, such as Basta® in crops like banana, indirectly alters soil microbial communities and their activities through loss of vegetation cover and should only be used as a component of an integrated weed management system
Feral pigs
No full textWild boar and feral pigs are the most widely distributed, medium-large sized free-living terrestrial mammal in the world. Growing populations of wild boar and feral pigs, together with their resultant environmental, agricultural, cultural and social impacts, have focused increased attention on their control by humans. This article discusses the biology, behavior and ecology of wild boar and feral pigs, their impacts, pathogens transmitted, and strategic initiatives being implemented in USA, Europe, Australia, and Canada to reduce ongoing threats that these animals pose. Different management approaches are used in different countries to control populations and their impacts. The importance of compliance with relevant legislation, welfare, and processing requirements to ensure that wild boar can be certified to be fit for human consumption is also presented. This review highlights the lack of published literature on microbiological, technological and sensory quality attributes of meat obtained from feral pigs. The latter section of this article is therefore based on European studies that have examined factors including season, diet type and availability, age, carcass weight and gender on carcass, meat and sensory characteristics of wild boar
Phylogenetic relationships in the genus Mangifera based on whole chloroplast genome and nuclear genome sequences
No full textThe genus Mangifera (Anacardiaceae) includes 69 species with Mangifera indica L. being the most important and predominantly cultivated species for commercial mango production. Although the species are classified based on morphological descriptors, molecular evidence has proposed the hybrid origin of two species suggesting the possibility that more of the species may be of hybrid origin. To analyze evolutionary relationships within the genus, 19 samples representing 14 Mangifera species were sequenced. Whole chloroplast genomes and 47 common single-copy nuclear gene sequences were assembled and used for phylogenetic analysis using concatenation and coalescence-based methods. The chloroplast genome size varied from 151,752 to 158,965 bp with M. caesia and M. laurina having the smallest and largest genomes, respectively. Annotation revealed 80 protein-coding genes, 31 tRNA and four rRNA genes across all the species. Comparative analysis of whole chloroplast genome sequence and nuclear gene-based phylogenies revealed topological conflicts suggesting chloroplast capture or cross-hybridization. The chloroplast genomes of M. altissima, M. applanata, M. caloneura and M. lalijiwa were similar to those of M. indica (99.9% sequence similarity). Their close sequence relationship suggests a common ancestry and likely cross-hybridization between wild relatives and M. indica. This study provides improved knowledge of phylogenetic relationships in the genus Mangifera, indicating extensive gene flow among the different species, suggesting that hybridisation may be common within the genus
Life cycle, host specificity and potential impact of a gall-inducing thrips Acaciothrips ebneri, a biological control agent for prickly acacia (Vachellia nilotica subsp. indica) in Australia
Get PDFPrickly acacia (Vachellia nilotica subsp. indica (Benth.) Kyal. & Boatwr.; Fabales: Fabaceae) is a Weed of National Significance and a target for biological control in Australia. Currently there are no effective biological control agents for the weed in Australia. Based on genetic and climate matching, a gall thrips (Acaciothrips ebneri Karny; Thysanoptera: Phlaeothripidae) inducing rosette galls resulting in shoot tip dieback, was identified as a prospective biological control agent from Ethiopia. No-choice host-specificity tests were conducted on 59 test plant species in a high security quarantine in Brisbane, Australia. Acaciothrips ebneri is host-specific, inducing galls and reproducing only on prickly acacia. Acaciothrips ebneri, as predicted by the CLIMEX model, is suited to hot and arid western Queensland where major prickly acacia infestations occur. The Australian Government approved A. ebneri for field release in October 2022. This is the first time a true gall-inducing thrips has ever been approved as a weed biological control agent. Field releases commenced in January 2023 and are in progress. There are early signs of field establishment resulting in shoot tip die back in the field, and field release and monitoring will continue
The untold history of banana bunchy top disease
Get PDFOf all the plant diseases that occur in Australia, banana bunchy top disease would rank high on any list of those that have had the greatest impact on society. Bunchy top first became a major problem in Australia during World War 1 in the Tweed Valley in New South Wales, close to the border of Queensland. The Soldier Settlement Scheme was initiated to provide a livelihood for returned soldiers, and the Northern Rivers region of New South Wales was chosen as the site for a new subtropical fruit industry. Physically and psychologically damaged men were encouraged to settle on the land to grow bananas, only to be left in ruins within two years because bunchy top had destroyed their plantations. Bunchy top did not discriminate, and many other well-established growers also ‘went broke’. The cries for assistance from the banana growers made it to the federal Parliament in Melbourne, and a Bunchy Top Investigation Committee was formed in 1924 with funding equally contributed by the New South Wales, Queensland, and Australian Governments. Charles Magee was the full-time plant pathologist appointed to the investigation, and he did most of the research. Most histories of the bunchy top research program follow the written accounts of Magee, but he only provided a narrow perspective. Several of the major hypotheses about the epidemiology of bunchy top disease, such as that it was spread in the plant’s suckers and was vectored by the banana aphid Pentalonia nigronervosa, were established by growers such as William John (aka Jack) Burton Marks well before the Bunchy Top Investigation Committee began. This paper describes the beginnings of the subtropical banana industry, the introduction of bunchy top disease, and efforts by the scientific and farming communities to find a preventative treatment or cure for the disease
Joseph Bancroft’s discovery of Fusarium Wilt of banana
Get PDFn the early decades of British settlement at Sydney Cove in 1788, the struggling colonials tried their hand at growing edible bananas but invariably failed. However, they grew extremely well in the Moreton Bay colony (Brisbane) and over time banana growing became an important agricultural industry there, particularly after the introduction of the Cavendish variety. All was progressing well until a new disease appeared in plantations around Brisbane in the early 1870s. The medical practitioner and naturalist Joseph Bancroft investigated the problem and concluded that a fungus was implicated as the causal agent. In the early 1900s, following serious outbreaks of a disease with similar symptoms in Caribbean countries (where it was called Panama Disease), the American bacteriologist Erwin Frink Smith studied the same disease in Cuba, and named the pathogen Fusarium cubense. Another American scientist, Elmer Walker Brandes, conclusively proved that Fusarium cubense (now called Fusarium oxysporum f.sp. cubense) was the cause of the banana disease. Bancroft’s discovery of the disease now called Fusarium Wilt not only predates other reports of the disease in the Caribbean but also represents the first scientific investigation of a plant disease in Australia