Glucosinolate composition and anti-cancer potential of daikon and radish sprouts

Daikon and radish sprouts contain high levels of glucoraphenin, a glucosinolate which hydrolyses to form sulphoraphene. Sulphoraphene, like sulphoraphane from broccoli, is a potent inducer of phase 2 detoxification enzymes and consequently has potential anti-cancer action. Unlike broccoli however, daikon and radish do not possess epithiospecifier protein, a protein that inhibits conversion of glucosinolates to isothiocyanates, and consequently they may represent more suitable sources of phyto-chemicals with anti-cancer potential. Concentrations of glucoraphenin were highest in the seed, declining exponentially with sprout development. The rate of decline was observed to vary considerably between varieties of daikon and radish, with some varieties maintaining significantly high levels of glucoraphenin. Varieties maintaining a high level of glucoraphenin included 'Cherry Belle' and 'French Breakfast'.

The distribution of Fasciola hepatica in Queensland, Australia, and the potential impact of introduced snail intermediate hosts

A survey was conducted to establish the distribution of the liver fluke, Fasciola hepatica, in the state of Queensland, Australia, and to evaluate the impact of the introduced snail intermediate hosts, Pseudosuccinia columella and Austropeplea viridis. Serum samples from a total of 5103 homebred cattle in 142 beef herds distributed throughout the state and 523 pooled milk samples from dairy herds from the state's major dairying regions were tested for antibodies to F. hepatica by ELISA. Snails were collected on infected properties around the limits of the F. hepatica distribution. F. hepatica infection was detected in 44 dairy herds and two beef herds. The distribution of infected herds indicates that F. hepatica is established only in southeast Queensland. The distribution there was patchy but the parasite was more widespread than suggested by an earlier survey. The predominant intermediate host species found along the northern limit of the distribution was P. columella. We conclude that the introduction of P. columella and A. viridis has not yet had a major impact on the distribution of F. hepatica in Queensland. However, the presence of P. columella, which is much more adaptable to tropical habitats than the native intermediate host, Austropeplea tomentosa, at the northern limit of the F. hepatica distribution suggests that there is potential for the parasite to expand its range.

Patterns in the distribution and abundance of female eastern king prawns, Melicertus plebejus (Hess, 1865), capable of spawning and reproductive potential in waters off

Linear mixed models were used to test the null hypothesis that there were no differences between seasons and locations in the reproductive potential of female eastern king prawns, Melicertus plebejus along the east coast of Australia. Three samples were collected in each season between autumn 1991 and winter 1992 (inclusive). Females capable of spawning were found at all locations but proportions were greater in lower than higher latitudes. Females capable of spawning were not found at the southern (highest latitude) most location in all seasons. There was a significant interaction in reproductive potential between seasons and locations suggesting that patterns among seasons differed between locations and vice versa. Reproductive potential was greatest amongst the northern (lower latitudes) most locations and was greatest in autumn at these locations. Seasonal patterns were less pronounced further south (higher latitudes). The length composition of females in catches differed between locations with more larger prawns found in samples from northern locations. The challenge that remains is to quantify the oceanic sources of larvae that contribute to recruitment in each nursery area and the estuarine sources of juveniles that contribute adults back to the effective spawning stock. Maintaining the effective spawning stock and important nursery areas are crucial to the sustainability of this resource.

Pyriproxyfen controls silverleaf whitefly, Bemisia tabaci (Gennadius), biotype B (Homoptera: Aleyrodidae) (SLW) better than buprofezin in bitter melons Momordica charantia L. (Cucurbitaceae)

To improve compatibility between chemical and biological controls, the use of selective insecticides such as insect growth regulators (IGRs) is crucial. In cucurbits, the use of pyriproxyfen (an IGR) has been shown by others to be an effective method of reducing the number of sap-sucking insects, especially silverleaf whitefly, Bemisia tabaci (Gennadius) Biotype B (SLW). Therefore, we compared pyriproxyfen and buprofezin (an IGR) with that of no treatment (control) in a bitter melon crop for the control of populations of SLW and for their effects on fruit production. Pyriproxyfen controlled SLW and tended to have heavier fruits than the control treatment and reduced the abundance of nymphs and exuvia. Buprofezin showed no evidence in controlling SLW compared with the pyriproxyfen and control treatments. Neither pyriproxyfen nor buprofezin had any effect on the number of harvested fruit or overall fruit yield, but the average weight per fruit was higher than the control treatment. Pyriproxyfen was effective in controlling whitefly populations in bitter melons, and both pyriproxyfen and buprofezin may have the potential to increase yield. Their longer-term use may increase predation by natural enemies as they are species-specific and could favour build up of natural enemies of SLW. Thus, the judicious use of pyriproxyfen may provide an effective alternative to broad-spectrum insecticides in small-scale cucurbit production.

New efforts at biological control of Mikania micrantha H.B.K. (Asteraceae) in Papua New Guinea and Fiji.

New efforts at biological control of Miconia calvescens (Melastomataceae) is a serious invader in the tropical Pacific, including the Hawaiian and Tahitian Islands, and currently poses a major threat to native biodiversity in the Wet Tropics of Australia. The species is fleshy-fruited, small-seeded and shade tolerant, and thus has the potential to be dispersed widely and recruit in relatively intact rainforest habitats, displacing native species. Understanding and predicting the rate of spread is critical for the design and implementation of effective management actions. We used an individual-based model incorporating a dispersal function derived from dispersal curves for similar berry-fruited native species, and life-history parameters of fecundity and mortality to predict the spatial structure of a Miconia population after a 30 year time period. We compared the modelled population spatial structure to that of an actual infestation in the rainforests of north Queensland. Our goal was to assess how well the model predicts actual dispersion and to identify potential barriers and conduits to seed movement and seedling establishment. The model overpredicts overall population size and the spatial extent of the actual infestation, predicting individuals to occur at a maximum 1,750 m from the source compared with the maximum distance of any detected individual in the actual infestation of 1,191 m. We identify several characteristic features of managed invasive populations that make comparisons between modelled outcomes and actual infestations difficult. Our results suggest that the model’s ability to predict both spatial structure and spread of the population will be improved by incorporating a spatially explicit element, with dispersal and recruitment probabilities that reflect the relative suitability of different parts of the landscape for these processes. Mikania micrantha H.B.K. (Asteraceae) in Papua New Guinea and Fiji.

Inter-seasonal population dynamics and pest status of Bemisia tabaci (Gennadius) biotype B in an Australian cropping system

Bemisia tabaci, biotype B, commonly known as the silverleaf whitefly (SLW) is an alien species that invaded Australia in the mid-90s. This paper reports on the invasion ecology of SLW and the factors that are likely to have contributed to the first outbreak of this major pest in an Australian cotton cropping system, population dynamics of SLW within whitefly-susceptible crop (cotton and cucurbit) and non-crop vegetation (sowthistle, Sonchus spp.) components of the cropping system were investigated over four consecutive growing seasons (September-June) 2001/02-2004/05 in the Emerald Irrigation Area (EIA) of Queensland, Australia. Based on fixed geo-referenced sampling sites, variation in spatial and temporal abundance of SLW within each system component was quantified to provide baseline data for the development of ecologically sustainable pest management strategies. Parasitism of large (3rd and 4th instars) SLW nymphs by native aphelinid wasps was quantified to determine the potential for natural control of SLW populations. Following the initial outbreak in 2001/02, SLW abundance declined and stabilised over the next three seasons. The population dynamics of SLW is characterised by inter-seasonal population cycling between the non-crop (weed) and cotton components of the EIA cropping system. Cotton was the largest sink for and source of SLW during the study period. Over-wintering populations dispersed from weed host plant sources to cotton in spring followed by a reverse dispersal in late summer and autumn to broad-leaved crops and weeds. A basic spatial source-sink analysis showed that SLW adult and nymph densities were higher in cotton fields that were closer to over-wintering weed sources throughout spring than in fields that were further away. Cucurbit fields were not significant sources of SLW and did not appear to contribute significantly to the regional population dynamics of the pest. Substantial parasitism of nymphal stages throughout the study period indicates that native parasitoid species and other natural enemies are important sources of SLW mortality in Australian cotton production systems. Weather conditions and use of broad-spectrum insecticides for pest control are implicated in the initial outbreak and on-going pest status of SLW in the region.

Radish sprouts versus broccoli sprouts: a comparison of anti-cancer potential based on glucosinolate breakdown products.

Radish sprouts and broccoli sprouts have been implicated in having a potential chemoprotective effect against certain types of cancer. Each contains a glucosinolate that can be broken down to an isothiocyanate capable of inducing chemoprotective factors known as phase 2 enzymes. In the case of broccoli, the glucosinolate, glucoraphanin, is converted to an isothiocyanate, sulforaphane, while in radish a similar glucosinolate, glucoraphenin, is broken down to form the isothiocyanate, sulforaphene. When sprouts are consumed fresh (uncooked), however, the principal degradation product of broccoli is not the isothiocyanate sulforaphane, but a nitrile, a compound with little anti-cancer potential. By contrast, radish sprouts produce largely the anti-cancer isothiocyanate, sulforaphene. The reason for this difference is likely to be due to the presence in broccoli (and absence in radish) of the enzyme cofactor, epithiospecifier protein (ESP). In vitro induction of the phase 2 enzyme, quinone reductase (QR), was significantly greater for radish sprouts than broccoli sprouts when extracts were self-hydrolysed. By contrast, boiled radish sprout extracts (deactivating ESP) to which myrosinase was subsequently added, induced similar QR activity to broccoli sprouts. The implication is that radish sprouts have potentially greater chemoprotective action against carcinogens than broccoli sprouts when hydrolysed under conditions similar to that during human consumption.

Taxonomy, distribution and ecology of Zoysia macrantha desv., an Australian native species with turf breeding potential

Only three of the 11 species in the genus Zoysia Willd. have thus far contributed to commercially available turfgrass varieties. One of the neglected taxa is Z. macrantha Desv., an Australian native species further divided into two subspecies. The coarser Z. macrantha subsp. macrantha occurs on sand dunes, headlands and tidal areas along eastern and southeastern coasts from about 23 to 38°S latitude. The shorter, denser-growing Z. macrantha subsp. walshii M.E. Nightingale is found on the southern mainland (South Australia and Victoria from longitude 137° to 148°E and at latitudes higher than 36°S), adjacent offshore islands, and northern, eastern and central Tasmania to 43°S growing on the edges of coastal, sub-coastal and even inland salt lakes, in riverine environments, and from moist grassy depressions (both coastal and inland) to rocky headlands. The latter subspecies has the more discontinuous and specialised distribution, largely determined by the need for an appropriate level of peat, clay or silt in the soil to maintain adequate moisture during the dry summers in southern Australia while at the same time avoiding anything more than temporary waterlogging. It grows on low fertility soils ranging from strongly acid to neutral or mildly alkaline, and is often very closely grazed by marsupials. Both subspecies are salt and drought tolerant, but not notably shade tolerant. Their potential to add greater drought tolerance in particular to the Asian Zoysia material in current use through future breeding programs is discussed.

Sequences that adopt non-B-DNA conformation in form V DNA as probed by enzymic methylation

pBR322 form V DNA is a highly torsionally strained molecule with a linking number of zero. We have used sequence- specific DNA methylases as probes for B-DNA in this molecule, exploiting the inability of methylases to methylate single-stranded DNA and Z-DNA, both of which are known to occur in form V DNA. Some sequences in form V DNA were shown to be totally in the B-form, others were totally in an altered, unmethylatable conformation, while still other sites appeared to exist partly in altered and partly in normal B-conformation. Some potential Z-forming sequences (alternating pyrimidine/purine) of less than seven base-pairs were not in the Z conformation in form V DNA, whereas others did adopt an altered structure, indicating a modulating influence of flanking sequences. Furthermore, regions of imperfect alternating pyrimidine/purine structure were sometimes capable of adopting an altered structure. In addition, some regions of altered structure had no apparent Z-forming sequences, nor were they in polypurine stretches, which have also been proposed to form left-handed DNA. These non-B-DNA conformations may represent novel left-handed helical structures or sequences that become single stranded under torsional strain. Long regions of either altered (unmethylatable) DNA or B-DNA were not always observed. In fact, one region showed three transitions between B-like DNA and altered structure within 26 base-pairs.

Investigations into the potential for mixed cultures of banana prawns Penaeus merguiensis, sea mullet Mugil cephalus and rabbitfish Siganus nebulosus for bioremediation of aquaculture waste

To experimentally investigate the potential of mixed species polycultures for bioremediation of nutrient rich prawn farm effluent, a series of experiments was performed with banana prawns Penaeus (Fenneropenaeus) merguiensis, sea mullet Mugil cephalus and rabbitfish Siganus nebulosus to determine their compatibilities during particular life stages. Rabbitfish demonstrated a high tendency to prey upon banana prawn juveniles when no other food was available. Mullet of various sizes did not appear to prey upon banana prawn postlarvae (PL16) or juveniles in a fed or unfed environment. The study confirms the good potential for mullet and banana prawn polycultures.

Studies on the pro-oxidative properties and neurotoxic potential of Angeli's salt-derived nitroxyl (HNO/NO-)

The biological function of nitric oxide and its oxidized forms has received a great deal of attention over the past two decades. However much less attention has been focused on the reduced nitric oxide, nitroxyl (HNO). Unlike NO, HNO is highly reactive species and thus it needs to be generated by using donor compounds under experimental conditions. Currently there is only one donor available, Angeli s salt, which releases HNO in a controlled fashion under pysiological conditions. Prior studies have shown the pro-oxidative and cytotoxic potential of Angeli s salt compared to NO donors. The high reactivity of HNO with cysteine thiols is considered to form the biochemical basis for its unique properties compared to other nitrogen oxides. Such thiol modification cold result in disturbances of vital cellular functions and subsequently to death of disturbance sensitive cells, such as neurons. Therefore modification of proteins and lipids was studied in vitro and the potential neurotoxicity was studied in vivo by local infusion of Angeli s salt into the rat central nervous system. The results show that under aerobic in vitro conditions, HNO can, subsequent to autoxidation, cause irreversible oxidative modification of proteins and lipids. These effects are not however seen in cell culture or following infusion of Angeli s salt directly into the rat central nervous tissue likely due to presence of lower oxygen and higher thiol concentration. However, due to high reactivity with thiols, HNO can cause irreversible inactivation of cysteine modification sensitive enzymes such as cysteine proteases papain in vitro and cathepsin B in cell culture. Furthermore it was shown that infusion of HNO releasing Angeli s salt into the rat central nervous system causes necrotic cell death and motor dysfunction following infusion into the lumbal intrathecal space. In conclusion, the acute neurotoxic potential of Angeli s salt was shown to be relatively low, but still higher compared to NO donors. HNO was shown to affect numerous cellular processes which could result in neurotoxicity if HNO was produced in vivo.

Residue Potential of Norsesquiterpene Glycosides in Tissues of Cattle Fed Austral Bracken (Pteridium esculentum).

Austral bracken, Pteridium esculentum, occurs widely in Australian grazing lands and contains both the known carcinogen ptaquiloside and its hydroxy analogue, ptesculentoside, with untested carcinogenic potential. Calves were fed a diet containing 19% P. esculentum that delivered 1.8 mg of ptaquiloside and 4.0 mg of ptesculentoside per kilogram of body weight (bw) per day to explore the carcass residue potential of these compounds. Concentrations of ptaquiloside and ptesculentoside in the liver, kidney, skeletal muscle, heart, and blood of these calves were determined as their respective elimination products, pterosin B and pterosin G, by HPLC-UV analysis. Plasma concentrations of up to 0.97 mu g/mL ptaquiloside and 1.30 mu g/mL ptesculentoside were found, but were shown to deplete to <10% of these values within 24 h of bracken consumption. Both glycosides were also detected in all tissues assayed, with ptesculentoside appearing to be more residual than ptaquiloside. Up to 0.42 and 0.32 mu g/g ptesculentoside was present in skeletal muscle and liver, respectively, 15 days after bracken consumption ended. This detection of residual glycosides in tissues of cattle feeding on Austral bracken raises health concerns for consumers and warrants further investigation.

Computer-model for vedavati groundwater basin .3. Irrigation potential

An estimate of the irrigation potential over and above the existing utilization was made based on the ground water potential in the Vedavati river basin. The estimate is based on assumed crops and cropping patterns as per existing practice in the various taluks of the basin. Irrigation potential was estimated talukwise based on the available ground water potential identified from the simulation study. It is estimated that 84,100 hectares of additional land can be brought under irrigation from ground water in the entire basin.

Evaluation of wood characteristics of tropical post-mid rotation plantation Eucalyptus cloeziana and E. pellita: Part (b) Accelerated seasoning of sawn timber.

Drying trials were conducted using two species of plantation grown eucalypt timbers: 19-year-old Eucalyptus cloeziana (Gympie messmate) and 15-year-old Eucalyptus pellita (red mahogany). The objective of this study was to gain an understanding of the drying potential of young plantation grown material using accelerated seasoning methods, a process expected to be critcal to the success of plantation hardwood products entering value added markets. The findings are encouraging, indicating that both species can be dried using conventional drying techniques much faster than industry is currently achieving when drying native forest timber. The results suggest that there is a definite drying time advantatge in vacuum drying over conventional methods for 19-year-old E. cloeziana. The findings have shown that through careful schedule manipulation and adjustment, the grade quality can be optimised to suit the desired expectation. As this study was limited to only a small number of trials, time and quality improvements are expected to be realised for both conventional and vacuum drying methods as more research is conducted.

A review of potential contaminants in Australian livestock feeds and proposed guidance levels for feed

Contaminants of man-made and natural origin need to be managed in livestock feeds to protect the health of livestock and that of human consumers of livestock products. This requires access to information on the transfer from feed to food to inform risk profiles and assessments, and to guide management interventions such as regulation or Hazard Analysis Critical Control Point approaches. This paper reviews contaminants of known and potential concern in the production of livestock feeds in Australia and compares existing but differing state and national regulatory standards with international standards. The contaminants considered include man-made organic chemical contaminants (e.g. legacy pesticides), elemental contaminants (e.g. arsenic, cadmium, lead), phytotoxins (e.g. gossypol) and mycotoxins (e.g. aflatoxins). Reference is made to scientific literature and evaluations by regulators to propose maximum levels that can be used for guidance by those involved in managing contamination incidents or developing feed safety programs. © 2013 CSIRO.