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Structural Characteristics and Immunological Function of a New Non-Starch Polysaccharide from Red Sprout Taro
No full textTaro is a tuber crop that is used for nutritional and medicinal purposes due to its abundance of non-starch polysaccharides (NSPs). Red Sprout taro is a local variety in Southern China, but the characteristics and bioactivities of its NSPs are currently unknown. In this study, NSPs were isolated from the corms of Red Sprout taro using hot-water extraction, ion-exchange chromatography, and ethanol precipitation; their molecular weight, monosaccharide composition, structural formulae, and immunomodulatory effects were examined. A novel NSP named Colocasia esculenta polysaccharide 1 (CEP1) was purified and characterized and was shown to mainly consist of glucose (60.49%) and galactose (25.92%) and have a molecular weight of 4556.272 kDa. The backbone of CEP1 consisted primarily of →4)-α-D-Glcp-(1→, →4,6)-β-D-Galp-(1→, and →3)-β-D-Galp-(1→ residues, with a branch consisting of the β-D-Glcp-(1→ residue. In addition, 25–400 µg/mL CEP1 was shown to have immunomodulatory effects on RAW264.7 macrophages. CEP1 not only increased cell viability, phagocytic capacity, inducible nitric oxide synthase secretion, and nitric oxide generation in RAW264.7 cells, but it also activated M1 and M2 macrophages to generate tumor necrosis factor α, interleukin 6, transforming growth factor β, and interleukin 10. These findings could lead to the use of CEP1 from Red Sprout taro as a possible immunomodulatory polysaccharide in functional foods
Understanding the cocoa genetic resources in the Pacific to assist producers to supply the growing craft market
Get PDFThe Pacific countries of Fiji, Samoa, Solomon Islands, and Vanuatu account for less than 2% of the world?s cacao dry bean production. To capitalise on the rapidly expanding origin craft cocoa market, understanding the genetic attributes of Theobroma cacao in the Pacific is essential. A six-year ACIAR-funded project collected 1647 dried leaf samples from research stations and smallholder farms to identify the population ancestry of T. cacao in the partner countries. Using SNP marker profiling, the study identified germplasm high in Amelonado, which represents the majority of material throughout the Pacific. However, the study also identified samples high in the remaining nine genetic groups, including Criollo, Nanay, IMC (Iquitos), Guiana, Parinari (Marañón), Nacional, Ucayali (Contamana), LCT EEN (Curaray), and Purus, which were distributed throughout the Pacific. The results, if utilised in local selection trials, could reposition growers in the Pacific countries, allowing them to supply the growing origin craft cocoa market, with genetically unique beans. Cocoa genetics was one aspect of a project incorporating production and postharvest research to refocus the commodity based cocoa industry to a supplier of high-quality beans of unique Pacific cocoa origin to the rapidly expanding craft ?bean to bar? cocoa industry
What is the latest random weed resistance survey telling us about paraquat and 2,4-D?
Get PDFTake home messages
• Resistance to the Group 22 herbicides paraquat and paraquat + diquat has been found in feathertop Rhodes grass (Chloris virgata) and tall fleabane (Conyza sumatrensis), respectively
• 2,4-D (Group 4) resistance has been found in 5 and 8% of common sowthistle and wild radish populations respectively from the northern cropping region
• Group 22 herbicides are important components of the double knock strategy commonly used for effective control of many northern region weeds. Alternative herbicide options for this use practice are limited
• To manage herbicide resistance, alternative herbicide and non-chemical tactics should be used in combination
Impact of factors contributing to internal disorders of mango (Mangifera indica L.) fruit—A systematic literature review
Get PDFThe expression of internal disorders is a complex phenomenon due to the interaction of genotype, environment, and management practices at the pre-harvest, harvest, and post-harvest stages. This study aims to provide a comprehensive overview of factors associated with, and have been investigated in relation to, the susceptibility and expression of internal disorders in mango. In this context, a systematic literature review was conducted to identify, extract, and analyse the most pertinent data. Six hundred and fifty-seven studies were sourced from three databases. Of these, 72 were relevant after screening based on exclusion-inclusion criteria. An additional nine relevant studies were identified through manual searches and included in the final data synthesis. From the 81 studies, the prevalent disorders were spongy tissue and jelly seed, followed by flesh browning and soft nose. ‘Alphonso’ expressed only spongy tissue disorder. By contrast, ‘Tommy Atkins’ simultaneously expressed multiple disorders, viz., soft nose, jelly seed, and stem-end cavity. Mineral composition of flesh and exposure to heat post-harvest (viz., sunlight, phytosanitary heat treatment, and elevated storage temperature) were prominent in association with IDs expression. Relatively high N, N/Ca, Mg/Ca, and K/Ca ratios and relatively low Ca and B were related to most disorders. With K and Mg, studies inconsistently suggested positive and inverse relationship with a particular disorder. While individual studies suggest casual relationships, there was a relative dearth of pre-harvest work on soil characteristics, growing conditions (e.g., temperature, rain, and VPD), crop physiology (e.g., age and biennial bearing) and management practices (e.g., fertilisation and irrigation) in the literature. This review provides a benchmark against which future research might adopt holistic approaches to contiguously ascertain predisposition of mango fruit to internal disorders across the pre-harvest, harvest, and post-harvest continuum
Postharvest diseases of mangoes in Fiji
Get PDFDespite considerable research globally on postharvest diseases of mango, virtually no work has been done to determine the occurrence of these diseases and their causal agents in Fiji. This study is the first major field and market survey of postharvest diseases of mango in Fiji. For the field survey, fruits from five local mango cultivars were harvested at each of five locations. Fruits from five imported cultivars were also harvested from one location in Nadi. For the market survey, vendors were selected at five municipal markets for fruit collection, along with ten roadside stalls. For field and market surveys, fruits were incubated at 23°C and assessed for postharvest disease (incidence and severity of body rots and stem end rots) when ripe. Isolations were made from disease lesions and fungal cultures were identified using multilocus sequence typing. High incidences of body and stem end rots were recorded across all surveys. In the field survey of local cultivars, ?Salusalu? fruits were found to have the lowest severity of body rot and stem end rot on average, while for imported cultivars, ?Nam Doc Mai? had the lowest average severity of these diseases. The market survey showed that ?Salusalu? had a lower incidence of anthracnose on the body of fruit compared to all other cultivars, although it did have a surprisingly high incidence of stem end rot at some localities. Fungal isolates from anthracnose lesions in the field and market surveys were identified as Colletotrichum asianum, C. simmondsii and C. fructicola. C. asianum was the predominant species associated with anthracnose symptoms, accounting for 97% of isolations. Lasiodiplodia theobromae and Neofusicoccum parvum were the predominant species found in association with mango stem end rot symptoms. Other species isolated from mango stem end rot in lesser numbers included L. brasiliensis, N. umdonicola and N. kwambonambiense. All of these fungi represent new reports for Fiji
The pathogenic diversity and host range of Colletotrichum spp. causing pepper spot and anthracnose of lychee (Litchi chinensis) in Australia
Get PDFLychee pepper spot, a field disease affecting lychee fruit skin, pedicels and petioles, is caused by Colletotrichum siamense, a fungal pathogen within the gloeosporioides species complex. Members of Colletotrichum from the gloeosporioides species complex and occasionally those from the acutatum species complex also cause postharvest anthracnose of lychee. Pepper spot was first described in Australia many years after anthracnose on lychee was first described, giving rise to the hypothesis that a novel species or strain within the gloeosporioides species complex causes pepper spot. In the present study, 19 isolates of Colletotrichum spp., collected from pepper spot and anthracnose symptoms on lychee fruit, representing 13 different genotypes across five species, were inoculated onto lychee fruit in the field or on detached fruit in the laboratory, to understand more about their pathogenic diversity. We found that symptoms were specific to genotype of the pathogen, as three genetically similar isolates of C. siamense consistently caused pepper spot and anthracnose, whilst other isolates caused anthracnose only. Cross-inoculation studies on detached fruit of lychee, banana, avocado and mango also provided some evidence of host specialization in isolates of C. siamense infecting lychee in Australia. Our experiments provided further evidence that detached fruit assays cannot be used as a reliable proxy for field inoculation studies. This research confirms that C. siamense is a causal agent of both lychee pepper spot and lychee anthracnose in Australia, and Colletotrichum alienum and Colletotrichum queenslandicum are reported as causal agents of anthracnose of lychee for the first time
NEXUS project: exploring profitable, sustainable livestock businesses in an increasingly variable climate
Get PDFChanging climates, and increased pressure from government and consumers to reduce the impacts of red meat on the environment threaten the viability of red meat production in Australia. We used bioeconomic modelling of a constructed case study farm in the Northern Downs region of Queensland to understand the impacts of a future climate (centred on 2050) on the productivity, profitability, and sustainability of beef production, and to evaluate a range of interventions. We also used semi-structured interviews to understand human adaptive and transformation capacity. Without changes to management, productivity, profitability, and sustainability of beef production in the Northern Downs region is predicted to decrease by 2050. Of the activities modelled, improving the feedbase through oversowing of herbaceous legumes, and transitioning from a breeder herd to steer turnover operation resulted in the greatest improvements in productivity and profitability. Large decreases in methane emissions, on a per ha and per kg liveweight sold basis, were possible through changing to a steer turnover operation and through the application of novel technologies that could provide reductions in the production of enteric methane. The results provide an indication of potential adaptation pathways for the industry and highlight gaps for future research and development
Covariance Clustering: Modelling Covariance in Designed Experiments When the Number of Variables is Greater than Experimental Units
Get PDFThe size and complexity of datasets resulting from comparative research experiments in the agricultural domain is constantly increasing. Often the number of variables measured in an experiment exceeds the number of experimental units composing the experiment. When there is a necessity to model the covariance relationships that exist between variables in these experiments, estimation difficulties can arise due to the resulting covariance structure being of reduced rank. A statistical method, based in a linear mixed model framework, is presented for the analysis of designed experiments where datasets are characterised by a greater number of variables than experimental units, and for which the modelling of complex covariance structures between variables is desired. Aided by a clustering algorithm, the method enables the estimation of covariance through the introduction of covariance clusters as random effects into the modelling framework, providing an extension of the traditional variance components model for building covariance structures. The method was applied to a multi-phase mass spectrometry-based proteomics experiment, with the aim of exploring changes in the proteome of barley grain over time during the malting process. The modelling approach provides a new linear mixed model-based method for the estimation of covariance structures between variables measured from designed experiments, when there are a small number of experimental units, or observations, informing covariance parameter estimates
Timber Production Opportunities from Private Native Forests in Southern Queensland
Get PDFHistorically, Queensland’s private native forests have supplied between 40 and 70% of the hardwood resource to the state’s primary processors. Hardwood timber production from state-owned native forests and plantations in Queensland has decreased substantially in recent decades, increasing the hardwood timber industry’s reliance on private native forests. However, timber production opportunities from these forests are poorly understood. This study assessed the future wood supply capacity from private native forests in southern Queensland assuming alternative levels of landowner interest in management for timber production and willingness to invest in silvicultural treatment. Commercial and harvestable private native forests in southern Queensland were classified into six forest types and their spatial distributions were assessed. Potential growth rates for each forest type were estimated based on available literature and expert opinion, and their ability to supply logs to industry with and without silvicultural treatments was projected. Commercial and harvestable private native forests were found to cover an area of approximately 1.9 M ha in southern Queensland, of which spotted gum (693,000 ha) and ironbark (641,500 ha) forest types are most common. The private native forest estate is distributed over 17,665 landholdings (LotPlans), with 17% of these accounting for 66% of the commercial and harvestable resource. Most private native forests have not been actively managed for timber production and are in poor condition. Nevertheless, they presently have the potential to supply between about 150,000 and 250,000 m3 of logs to industry per annum. Silvicultural treatments were found to have the potential to increase the mean annual increment of these forests by a factor of between two and four, indicating substantial opportunities to increase harvestable log volumes in the medium and long-term. Private native forests in southern Queensland could potentially more than compensate for the supply gap left by the declining area of state-owned native forests that are available for timber harvesting. Actual forest management performed and log volumes supplied to market will depend on the forest management decisions of thousands of individual landholders, which are influenced by their heterogeneous management objectives, the policy environment, perceptions of sovereign risk, timber markets and the long payback periods in forestry. An accommodating forest policy environment and landholder willingness to invest in forest management could maintain and potentially increase private hardwood log supply to industry, which would support farm income diversification and regional employment opportunities
Personal electric deterrents can reduce shark bites from the three species responsible for the most fatal interactions
Get PDFThe frequency of unprovoked shark bites is increasing worldwide, leading to a growing pressure for mitigation measures to reduce shark-bite risk while maintaining conservation objectives. Personal shark deterrents are a promising and non-lethal strategy that can protect ocean users, but few have been independently and scientifically tested. In Australia, bull (Carcharhinus leucas), tiger (Galeocerdo cuvier), and white sharks (Carcharodon carcharias) are responsible for the highest number of bites and fatalities. We tested the effects of two electric deterrents (Ocean Guardian’s Freedom+ Surf and Freedom7) on the behaviour of these three species. The surf product reduced the probability of bites by 54% across all three species. The diving product had a similar effect on tiger shark bites (69% reduction) but did not reduce the frequency of bites from white sharks (1% increase), likely because the electrodes were placed further away from the bait. Electric deterrents also increased the time for bites to occur, and frequency of reactions and passes for all species tested. Our findings reveal that both Freedom+ Surf and Freedom7 electric deterrents affect shark behaviour and can reduce shark-bite risk for water users, but neither product eliminated the risk of shark bites entirely. The increasing number of studies showing the ability of personal electric deterrents to reduce shark-bite risk highlights personal protection as an effective and important part of the toolbox of shark-bite mitigation measures