List of Records in School of Land, Crop and Food Sciences Publications - UQ eSpace

ABA effects on ethylene production, PAL activity, anthocyanin and phenolic contents of strawberry fruit

Jiang, YM og Joyce, DC — 2007-10-17T11:54:11Z

Effects of exogenously applied abscisic acid (ABA) on ethylene production rate, phenylalanine ammonia-lyase ( PAL) enzyme activity, and anthocyanin and phenolic concentrations in harvested strawberry cv. Everest fruit were evaluated. Colouration and firmness were also assessed on fruit held for 3 days at 20 degreesC. ABA treatment accelerated fruit colour and softening. Treatment with 10(-5) or 10(-4) mol ABA l(-1) stimulated ethylene production. Anthocyanin and phenolic contents and PAL activity increased during storage, but more rapidly in ABA treated fruit. As a result, red colour development was accelerated. Endogenous ABA may play a role in strawberry fruit colour development during ripening through up-regulation of ethylene production and PAL activity.

About this manual

2007-08-14T11:28:44Z

A breakthrough in DNA typing of Macadamia cultivars

2008-06-06T16:47:19Z

Abscisic acid analogue effects on the vase life and leaf crisping of cut Baccara roses

Pompodakis, NE og Joyce, DC — 2007-10-17T12:02:59Z

The plant growth regulator abscisic acid induces stomatal closure, which can reduce transpiration rate and extend vase life of cut flowers by maintaining a positive water balance. Analytical-reagent grade abscisic acid is, however, expensive. In this work, the effects of 2 potentially inexpensive synthetic analogues of abscisic acid were studied as to their effects on cut Baccara roses. Abscisic acid and its analogues PBI-365 and PBI-429 reduced transpiration and helped to increase fresh weight during the first few days of vase life. However, the reduction in transpiration rate brought about by abscisic acid and the analogues did not alter vase life. Sucrose in the vase solution at concentrations of 2 and 4% increased vase life of cut Baccara roses. However, the highest sucrose concentration ( 4%) caused leaf crisping, thereby reducing the quality of the flower stems. Abscisic acid and the analogue PBI-365 reduced this phytotoxicity by induction of stomatal closure and reduction of vase solution sucrose flux into the leaves.

A Canopy Architectural Model to Study the Competitive Ability of Chickpea with Sowthistle

2009-04-08T11:34:14Z

Accessing integrated Brassica genetic and genomic data using the BASC server

Love, C. G. og Edwards, D. — 2008-04-24T13:12:59Z

Accounting for co-extractable compounds (blank correction) in spectrophotometric measurement of extractable and total-bound proanthocyanidin in Leucaena spp

Dalzell, S. A. og Kerven, G. L. — 2007-08-14T18:26:46Z

Accurate prediction of scorpion toxin functional properties from primary structures

2007-08-15T05:51:53Z

Scorpion toxins are common experimental tools for studies of biochemical and pharmacological properties of ion channels. The number of functionally annotated scorpion toxins is steadily growing, but the number of identified toxin sequences is increasing at much faster pace. With an estimated 100,000 different variants, bioinformatic analysis of scorpion toxins is becoming a necessary tool for their systematic functional analysis. Here, we report a bioinformatics-driven system involving scorpion toxin structural classification, functional annotation, database technology, sequence comparison, nearest neighbour analysis, and decision rules which produces highly accurate predictions of scorpion toxin functional properties. (c) 2005 Elsevier Inc. All rights reserved.

Achievements in forest tree improvement in Australia and New Zealand 6: Genetic improvement and conservation of Araucaria cunninghamii in Queensland

Dieters, Mark og Nikles, D. G. og Keys, M. — 2008-04-09T14:16:27Z

Acibenzolar-S-methyl and methyl jasmonate treatments of glasshouse-grown freesias suppress post-harvest petal specking caused by Botrytis cinerea

Darras, AI og Joyce, DC og Terry, LA — 2007-08-15T09:41:05Z

Compounds that activate host plant defence responses potentially offer socio-environmentally sound alternative methods for disease control. In a series of glasshouse trials over 2 years, pre-harvest sprays with acibenzolar-S-methyl (ASM) and methyl jasmonate (MeJA) were tested for suppression of post-harvest infection of cut Freesia hybrida L. flowers by Botrytis cinerea. For the ASM treatments, variability in reducing the incidence of B. cinerea disease was observed between years freesia varieties, incubation temperatures and ASM concentrations. In the first year, the greatest reductions in lesion numbers on ASM-treated var. 'Cote d'Azur' were recorded using 2.86 mM ASM. For three different post-harvest temperature regimes, the relative reductions in lesion numbers, compared to untreated controls, were 45% at 5 degrees C, 40% at 12 degrees C and 30% at 20 degrees C, respectively. In the second year, lesion numbers were most reduced using 1.43 mM ASM to treat freesia var. 'Dukaat' flowers. Here, the relative reductions were to 44% at 5 degrees C, 26% at 12 degrees C and 51% at 20 degrees C. MeJA treatments were, in general, more consistently effective than ASM treatments in reducing lesion numbers and lesion diameters on cut freesia flowers. MeJA-treated (0.2 mM) freesia flowers (var. 'Dukaat') incubated at 20 degrees C showed relative reductions of 62%, and 45% for lesion number and lesion diameter, respectively. The differing efficacy between ASM and MeJA treatments could be attributed to their differential abilities to induce the salicylic acid (SA)-mediated vs. the jasmonic acid (JA)-mediated host defence pathways, respectively.

Acid sulfate soil assessment and monitoring - a simple robust kit for use by farmers and other land managers - The Acid Test

Saffigna, P. G. — 2007-08-24T01:38:40Z

Acid sulphate soils and proposed selective ditching for mosquito control at Lake Doonella, Noosa, Queensland, Australia

Saffigna, P. G. og Hey, K. M. — 2007-08-24T00:39:03Z

Acid sulphate soils - implications with habitat modification for mosquito control in tropical Australia

Saffigna, P. G. og Dale, P. — 2007-08-24T00:38:58Z

A common-pool resource approach for water quality management: An Australian case study

2009-09-03T09:12:39Z

Water is perhaps one of the most studied types of common-pool resource (CPR) goods. Its quality, however, has not been discussed as much in the CPR literature as its quantity. We examine the significance of studying water quality from a CPR perspective, and then analyze implications for the formulation of institutional arrangements to improve water quality. We illustrate with a case study in South East Queensland, Australia. This involves a rural catchment (watershed) that contributes high sediment and some nutrient loads to the Brisbane River, where it affects urban water quality and visual amenity, water treatment costs, and dredging costs at the port. The pollutants then threaten marine water quality and habitat values for threatened species in Moreton Bay, a marine protected area. We analyze the potential for a CPR understanding to enhance the design and financing of a water quality management regime. Rather than seeking to supplant conceptualizations of externalities as a basis for design of policy instruments, we propose arrangements that combine the CPR and externality concepts to offer a powerful logic and financial basis for collective management. Market-based instruments could facilitate downstream populations to help pay for catchment restoration in return for enjoyment of improved water quality resulting from strengthened ecosystem services, while associated non-market-based instruments could help all parties understand and expand their roles under a common-pool management regime. We argue that recognition of CPR attributes provides a logic for cooperation and co-investment between stakeholders who are in a position to affect, or are affected by, water quality in different parts of a large river system.

A comparative map viewer integrating genetic maps for Brassica and Arabidopsis

2008-04-28T12:50:35Z

Background: Molecular genetic maps provide a means to link heritable traits with underlying genome sequence variation. Several genetic maps have been constructed for Brassica species, yet to date, there has been no simple means to compare this information or to associate mapped traits with the genome sequence of the related model plant, Arabidopsis. Description: We have developed a comparative genetic map database for the viewing, comparison and analysis of Brassica and Arabidopsis genetic, physical and trait map information. This web- based tool allows users to view and compare genetic and physical maps, search for traits and markers, and compare genetic linkage groups within and between the amphidiploid and diploid Brassica genomes. The inclusion of Arabidopsis data enables comparison between Brassica maps that share no common markers. Analysis of conserved syntenic blocks between Arabidopsis and collated Brassica genetic maps validates the application of this system. This tool is freely available over the internet on http://bioinformatics.pbcbasc.latrobe.edu.au/cmap. Conclusion: This database enables users to interrogate the relationship between Brassica genetic maps and the sequenced genome of A. thaliana, permitting the comparison of genetic linkage groups and mapped traits and the rapid identification of candidate genes.

A comparative study of interspecies mating of Phratora vulgatissima and P-vitellinae using behavioural tests and molecular markers

2007-09-19T18:50:05Z

The leaf beetle genus Phratora L. (Coleoptera: Chrysomelidae) has been used to study the ecology of host plant chemicals in herbivore preference, and the evolution of host use in chemical defence. Phratora vulgatissima and P. vitellinae are sympatric species distributed widely across Europe. Their trophic niches are largely separate due to strong differences in their host feeding preference, but they have occasionally been recorded together, feeding on Salix burjatica'Germany' and, only in early spring, on Populus trichocarpa (Torr & A. Gray) 'Trichobel'. Using behavioural tests and recently developed species-specific microsatellite markers, the intra- and interspecific mating of both beetle species were investigated. The microsatellite markers provided evidence that interspecific mating occurred under field conditions. Interspecific mating also took place under laboratory conditions, but less frequently than mating within species. Females of both species laid fewer eggs, and fewer eggs per clutch, when isolated with an interspecific male than with a conspecific male. Female P. vulgatissima were polyandrous, as microsatellite markers showed that their larvae were the progeny of both P. vulgatissima males that had been isolated with a single female. While only 0.55% of eggs laid in interspecific pair combinations hatched, microsatellite markers provided evidence of hybridisation between beetle species; however, these larvae died within a week when reared in a Petri dish containing 'Germany' and P. trichocarpa leaves. It can therefore be inferred that reproductive isolation is complete. The results are discussed in relation to species integrity and the implications for diverse mixtures of short-rotation coppice willow plantations.

A comparison of broiler performance on diets formulated on a total and digestible amino acid basis

2008-06-06T16:23:46Z

A comparison of Kodak Ultraspeed and Ektaspeed Plus dental X-ray films for the detection of dental caries

2007-08-14T17:09:12Z

Background: Using the fastest dental X-ray film available is an easy way of reducing exposure to ionizing radiation. However, the diagnostic ability of fast films for the detection of proximal surface caries must be demonstrated before these films will become universally accepted. Methods: Extracted premolar and molar teeth were arranged to simulate a bitewing examination and radiographed using Ultraspeed and Ektaspeed Plus dental X-ray films. Three different exposure times were used for each film type. Six general dentists were used to determine the presence and depth of the decay in the proximal surfaces of the teeth radiographed. The actual extent of the decay in the teeth was determined by sectioning the teeth and examining them under a microscope. Results: There was no significant difference between the two films for the mean correct diagnosis. However, there was a significant difference between the means for the three exposure times used for Ultraspeed film. The practitioners used were not consistent in their ability to make a correct diagnosis, or for the film for which they got the highest correct diagnosis. Conclusions: Ektaspeed Plus dental X-ray film is just as reliable as Ultraspeed dental X-ray film for the detection of proximal surface decay. The effect of underexposure was significant for Ultraspeed, but not for Ektaspeed Plus. Patient exposure can be reduced significantly with no loss of diagnostic ability by changing from Ultraspeed X-ray film to Ektaspeed Plus X-ray film.

A comparison of Kodak Ultraspeed and Ektaspeed Plus dental x-ray films for use in endodontics

2007-08-14T18:23:48Z

A comparison of Kodak Ultraspeed and Ektaspeed Plus dental X-ray films for use in endodontics

2007-08-14T16:19:04Z

Background: The advantage of using a faster film for length determination in endodontic therapy is obvious. However, for such a film to be generally accepted, it must demonstrate comparable diagnostic quality to traditionally used films. Methods: The comparative accuracy of canal length determination of Ultraspeed and Ektaspeed Plus dental X-ray films was assessed in maxillary first and second molars; for different canals, for different teeth, for different exposures, and for different examiners (five general dentists and three endodontic specialists). Results: In general, there were no significant differences between films, among examiners, or any interaction between films and exposures. That is, an assessor's ability to estimate lengths was not significantly influenced by the film type or by exposure used. There was a wide divergence in the individual assessor's ability to estimate lengths. Specialists estimated lengths more accurately than general practitioners and estimated lengths more accurately with Ektaspeed Plus film. Length determination in distobuccal and mesiobuccal canals was more accurate than in palatal canals. Most palatal canals were underestimated in length by more than 1mm. The use of file sizes larger in number than size 15 is recommended in these canals. Conclusion: For length determination, Ektaspeed Plus dental X-ray film is as effective as Ultraspeed film. Given the acceptable quality and accuracy of Ektaspeed Plus film, there seems to be no clinical reason to subject patients to greater radiation by using a slower film during endodontic therapy.

A comparison of total and digestible amino acids in diets for broilers and layers

2008-06-10T15:00:45Z

Eleven samples of food ingredients were analysed for their total and true digestible amino acid content, apparent metabolisable energy and other components. Large batches of these ingredients were retained for st broiler and a layer experiment. Four layer diets were formulated at 0.97 and 0.90 of total and digestible amino acid requirements for egg production using the analysed ingredients. Eight broiler diets were also formulated from 1.0 to 0.91 of total and digestible amino acid requirements in starter and finisher diets. Proximate and amino acid analyses and AME values were within the normal range for the 11 foodstuffs. Digestibility of amino acids was high with very few exceptions, e.g. cottonseed meal, meat and bone meal. Diets formulated on a total or digestible amino acid basis gave no differences in egg production parameters or broiler production parameters with no effect of level of inclusion. However, the main effects showed that diets formulated on a total compared to a digestible amino acid basis gave better growth rate and feed conversion efficiency in broilers. It was concluded that nutrient specifications for layers and broilers are not sufficiently precise to be able to differentiate between 1.97 and 0.90 of requirement for egg production or 1.0 and 0.91 for broiler growth. The use of digestible amino acids may be justified in diet formulations only when unusual protein concentrates with low amino acid digestibility values are used in large amounts. (C) 1999 Elsevier Science B.V. All rights reserved.

A Computerised Key for Seed Identification

2009-04-06T12:50:35Z

Australian Quarantine and Inspection Service (AQIS) regulates the quarantine requirements regarding seed imports in Australia. There are a number of seed testing laboratories in Australia which are currently servicing AQIS needs to prevent the entry of prohibited and restricted seeds. Current practices of identifying seeds by comparing an unknown seed with samples of known seeds or photographs of seeds are time consuming, costly and inefficient. A Seed Identification Key using a computerised database has been developed to identify prohibited and restricted seeds. There are currently 78 prohibited and 47 restricted seeds in the database. Lucid software was used to develop the Key because of its versatility in handling both text and image data. A total of 21 externally visible seed characters were identified as most suitable for development of the Key. Explanatory images and notes are attached to the character states to assist the user in correct selection of the state. The Key will be helpful to quarantine officers as well as seed analysts working in seed testing laboratories throughout Australia. It can also be used as an educational tool by agricultural scientists, students and others interested in seeds.

A Conceptual Analysis of Nitrogen From Trash in the Wet Tropics

2007-08-14T18:29:46Z

A convenient method for the estimation of bacterial alpha-amylase in dairy products

Deeth, H. C. og Sparks, Z. C. og Datta, N. — 2008-06-06T16:29:54Z

A cooperative research model - biological control of Parkinsonia aculeata and Landcare groups in northern Australia

Galea, V. J. — 2009-04-19T11:22:44Z

A critical comparison of the external and internal boron requirements for contrasting species in boron-buffered solution culture

Asad, A. og Bell, R. W. og Dell, B. — 2007-08-14T15:47:47Z

Despite reports that boron (B) requirements differ among plant species there is a shortage of critical evidence to demonstrate unequivocally whether species differ in internal or external B requirements or both. The present research was conducted to establish the external and internal B requirements of three contrasting species, a woody dicot (marri), an herbaceous dicot (sunflower) and a monocot (wheat) using B-buffered solution culture. Boron-buffered solution culture provided satisfactory control of external B concentrations ranging from 0.04 to 30 muM throughout the 20- (sunflower and wheat) or 40-day (marri) growth period. At low external B concentrations (less than or equal to 0.13 muM), the growth of marri and sunflower was severely depressed but by contrast the vegetative growth of wheat plants was satisfactory and free of B deficiency symptoms. Marri and sunflower plants achieved total maximum shoot growth at greater than or equal to1.2 muM B in solutions while wheat plants did so at greater than or equal to 0.6 muM B. The critical B concentrations (mg kg(-1) dry matter) in the youngest open leaf blades of marri, sunflower and wheat plants were 17.9, 19.7 and 1.2 on 20, 10 and 10 days after transplanting (DAT), respectively. Lower internal and external B requirements of wheat were matched by a lower uptake rate of B compared to marri and sunflower.

ACT Forestry Drift Measurement

2007-08-14T13:24:29Z

Activated and deactivated sintering of hydroxyapatite adsorbent using metallic additives

2007-08-23T22:33:41Z

Activating mango fruit defence to anthracnose disease.

2007-08-24T02:04:36Z

Active packaging of UHT milk to prevent the development of stale flavour during storage

2008-02-18T17:07:07Z

Indirectly processed UHT milk was packaged in Intasept (TM) aseptic pouches with (treatment) or without (control) oxygen-scavenging film and stored for 14 weeks at 26 +/- 0.3 degrees C. Samples were analysed at 0, 4, 8 and 14 weeks for dissolved oxygen, stale flavour volatiles (methyl ketones and aldehydes) and free fatty acids. Discriminative subjective analysis of odour by a consumer panel was also conducted. The oxygen-scavenging film was shown to significantly (p < 0.05) reduce dissolved oxygen content by 23-28% during storage. Significant reductions of 23-41% were also observed for some stale flavour volatiles, including three methyl ketones and two aldehydes. Free fatty acid levels remained far below threshold values, indicating that lipolytic rancidity would not interfere with the subjective analysis. However, the consumer panel failed to detect a significant difference in odour between the treatment and control samples. Copyright (c) 2006 John Wiley & Sons, Ltd.

Activity of HIV entry and fusion inhibitors expressed by the human vaginal colonizing probiotic Lactobacillus reuteri RC-14

2008-12-12T23:54:59Z

Novel therapeutic approaches are needed to combat the rapid increase in HIV sexual transmission in women. The probiotic organism Lactobacillus reuteri RC-14 which safely colonizes the human vagina and prevents microbial infections, has been genetically modified to produce anti-HIV proteins which were capable of blocking the three main steps of HIV entry into human peripheral blood mononuclear cells. The HIV entry or fusion inhibitors were fused to the native expression and secretion signals of BspA, Mlp or Sep in L. reuteri RC-14 and the expression cassettes were stably inserted into the chromosome. L. reuteri RC-14 expressed the HIV inhibitors in cell wall-associated and secreted forms. L. reuteri RC-14 expressing CD4D1D2-antibody-like fusion proteins were able to bind single or dual tropic coreceptor-using HIV-1 primary isolates. This is the first study to show that a well-documented and proven human vaginal probiotic strain can express potent functional viral inhibitors, which may potentially lower the sexual transmission of HIV.

Adaptation of rainfed lowland rice

Fukai, S. og Cooper, M. og Wade, L. J. — 2008-06-10T15:01:34Z

Rainfed lowland rice is defined as rice growing in bunded paddies that do not have any access to irrigation water. This rice ecosystem is important, particularly in South and Southeast Asia. The area occupied by this ecosystem in Asia was 36.4 million ha and the average grain yield was 2.30 t ha-1 in 1991 (IRRI, 1997). The area was about 25% of the total cultivated area for rice. Fischer (1996) argued that by the year 2025 the production of rice must be increased by 70% over current levels in order to meet growing food demands. Scobie et al. (1993) estimated that of the extra rice production required by the year 2030, 21% would have to come from the rainfed lowlands. Sustainable genetic and agronomic improvements of the yield of rainfed lowland rice are required if this projected increase in productivity is to occur.

Adaptation of sorghum: characterisation of genotypic flowering responses to temperature and photoperiod

2007-08-13T11:23:53Z

Sorghum [Sorghum bicolor (L.) Moench] is an important cereal crop grown in a wide range of tropical and temperate environments. This study was conducted to characterise the photothermal flowering responses of sorghum genotypes and to examine relationships between photothermal characteristics and environment of origin in order to better understand the phenological basis of adaptation to environment in sorghum. Twenty-four germplasm accessions and one hybrid from 24 major sorghum-growing areas were grown in a wide range of environments varying in temperature and photoperiod in India, Kenya and Mall between 1992 and 1995. Times from sowing to flowering (f) were recorded, and the responsiveness of 1/f to temperature and photoperiod was quantified using photothermal models. Times from sowing to flowering were accurately predicted in a wide range of environments using a multiplicative rate photothermal model. Significant variation in the minimum time to flower (F-m) and photoperiod sensitivity (critical photoperiod, P-c, and photoperiod-sensitivity slope, P-s) was observed among the genotypes; in contrast there was little variation in base temperature (Tb) Adaptation of sorghum to the diverse environments in which it is grown was largely determined by photoperiod sensitivity and minimum time to flower; photoperiod sensitivity determines bread adaptation to latitude (daylength), while variation in the minimum time to flower determines specific adaptation within smaller ranges of latitude, e.g. within the humid and sub-humid tropics.

Adaptations of Caustis blakei to low phosphorus conditions and its susceptibility to phosphorus toxicity

2007-08-23T20:37:47Z

Adaptation trials of Atriplex and Maireana species and their response to saline waterlogged conditions in Pakistan

Asad, A. — 2007-08-14T15:47:51Z

Utilization of salt affected wasteland by growing forage shrubs has enormous economic and environmental implication for developing countries like Pakistan, where approximately 6.3 million ha of the land is salt affected. Considering the importance of Atriplex and Maireana species, research has been conducted using their different species on the salt affected soils of Faisalabad. Most of Atriplex and Maireana species survived under the environmental conditions of Faisalabad and gave the good yield in the form of forage. Some of these species are woody and can be used for fuel purposes. Sixteen genotypes of Atriplex and Maireana were tested for their tolerance to waterlogging in order to identify halophytic fodder shrubs suitable for growth on secondary salt-affected and waterlogged farmland. The physiological and morphological responses of the species tested were typical of species with a generally poor tolerance to waterlogging. Despite this, some species (eg A. Amnicola) were surprisingly resistant, surviving up to five months of waterlogging at moderate salinity and high evapotranspirational demand. The most resistant species, A amnicola maintained higher transpiration rates, leaf water potentials and shoot extension rates than most other species during five weeks of waterlogging, and a return to control levels more quickly than other species after plots were drained. Although little morphological adaptation to waterlogged conditions was detected, a shallow and extensive lateral root system and the formation of many short aerenchymatous adventitious roots from procumbent branches appeared to advantage A. Amnicola in an environment highly heterogeneous in salinity and low in oxygen concentration. Shallow fibrous rooted species were quickly killed by waterlogging, although the procumbent branches of some individuals survived as clones if they developed adventitious roots.

Adaptive responses of wild mungbean (Vigna radiata ssp sublobata) to photo-thermal environment. II. Growth, biomass, and seed yield

Rebetzke, G. J. og Lawn, R. J. — 2007-08-15T08:20:04Z

The leaf growth, dry matter production, and seed yield of 11 wild mungbean ( Vigna radiata ssp. sublobata) accessions of diverse geographic origin were observed under natural and artificial photoperiod temperature conditions, to determine the extent to which genotypic differences could be attributed to adaptive responses to photo-thermal environment. Environments included serial sowings in the field in SE Queensland, complemented by artificial photoperiod extension and controlled-environment growth rooms. Photo-thermal environment influenced leaf growth, total dry matter production ( TDM), and seed yield directly, through effects of ( mainly cool) temperature on growth, and indirectly, through effects on phenology. In terms of direct effects, leaf production, leaf expansion, and leaf area were all sensitive to temperature, with implied base temperatures higher than usually observed in cultivated mungbean ( V. radiata ssp. radiata). Genotypic sensitivity to temperature varied systematically with accession provenance and appeared to be of adaptive significance. In terms of the indirect effects of photo-thermal environment, genotypic and environmental effects on TDM were positively related to changes in total growth duration, and harvest index was negatively related to the period from sowing to flowering, similar to cultivated mungbean. However, seed yield was positively related to the duration of reproductive growth, reflecting the indeterminate growth habit of the wild accessions. As a consequence, the wild accessions are more responsive to favourable environments than typically observed in cultivated mungbean, which is determinate in habit. It is suggested that the introduction of the indeterminate trait into mungbean from the wild subspecies would increase the responsiveness of mungbean to favourable environments, analogous to that of black gram ( V. mungo). Although the wild subspecies appeared more sensitive to cool temperature than cultivated mungbean, it may provide a source of tolerance to the warmer temperatures experienced during the wet season in the tropics.

Adaptive responses of wild mungbean (Vigna radiata ssp sublobata) to photo-thermal environment. I. Phenology

Rebetzke, G. J. og Lawn, R. J. — 2007-08-15T08:20:02Z

The phenology of 11 diverse accessions of wild mungbean was observed under natural and artificial photoperiod - temperature conditions, in order to examine whether genotypic differences might be attributed to adaptive responses to photo-thermal conditions. There was large variation in phenological response among accessions and across environments, much of which was due to differences in the duration of the pre-flowering phase. Accessions that flowered earlier tended to flower for longer, apart from 2 earlier flowering, inland Australian lines that were also earlier maturing. The patterns of response in time from sowing to flowering over environment were consistent with quantitative short-day photoperiodic adaptation, a conclusion supported by the effects of artificial day-length extension and by 'goodness of fit' of the observed responses to standard models relating rate of development to photoperiod and temperature. The fitted models indicated that rate of development towards flowering was hastened by warmer temperatures, and delayed by longer day lengths, with differential sensitivity between accessions to both factors. The models also suggested that photoperiod was more important for accessions collected closer to the equator, which were generally later flowering as a consequence. Conversely, temperature was relatively more important in lines from higher latitudes. Modelling also suggested that the period from first flowering to maturity was sensitive to photoperiod and temperature. Again, longer days appeared to prolong growth and delay maturity. However, cooler temperatures accelerated rather than slowed maturity, by suppressing further vegetative growth. The variation observed indicated that there is considerable scope for using the wild population to broaden the adaptation of cultivated mungbean. In particular, the unusual response of a late-flowering, photoperiod-insensitive accession warrants further study to establish whether the wild population contains a unique 'long juvenile' trait analogous to that being used for improving phenological adaptation in soybean.

Adding value to the hen's egg

Farrell, D. J. — 2007-08-24T01:14:38Z

A decision-making tool to minimise environmental and public health risk of pesticide application

2007-08-23T22:31:48Z

A digital imaging technique to quantify the incidence of internal browning in potato (Solanum tuberosum) tubers

Harper, S. M. og Blamey, F. P. C. — 2009-04-09T12:19:55Z

Adoption of tropical legume technology: an update on leucaena

Shelton, M. — 2008-05-06T10:05:58Z

Advances in agronomic research in the lowland rice environments of Laos

2007-08-14T12:44:02Z

Advances in application of climate prediction in agriculture

2007-08-14T16:54:51Z

Agricultural ecosystems and their associated business and government systems are diverse and varied. They range from farms, to input supply businesses, to marketing and government policy systems, among others. These systems are dynamic and responsive to fluctuations in climate. Skill in climate prediction offers considerable opportunities to managers via its potential to realise system improvements (i.e. increased food production and profit and/or reduced risks). Realising these opportunities, however, is not straightforward as the forecasting skill is imperfect and approaches to applying the existing skill to management issues have not been developed and tested extensively. While there has been much written about impacts of climate variability, there has been relatively little done in relation to applying knowledge of climate predictions to modify actions ahead of likely impacts. However, a considerable body of effort in various parts of the world is now being focused on this issue of applying climate predictions to improve agricultural systems. In this paper, we outline the basis for climate prediction, with emphasis on the El Nino-Southern Oscillation phenomenon, and catalogue experiences at field, national and global scales in applying climate predictions to agriculture. These diverse experiences are synthesised to derive general lessons about approaches to applying climate prediction in agriculture. The case studies have been selected to represent a diversity of agricultural systems and scales of operation. They also represent the on-going activities of some of the key research and development groups in this field around the world. The case studies include applications at field/farm scale to dryland cropping systems in Australia, Zimbabwe, and Argentina. This spectrum covers resource-rich and resource-poor farming with motivations ranging from profit to food security. At national and global scale we consider possible applications of climate prediction in commodity forecasting (wheat in Australia) and examine implications on global wheat trade and price associated with global consequences of climate prediction. In cataloguing these experiences we note some general lessons. Foremost is the value of an interdisciplinary systems approach in connecting disciplinary Knowledge in a manner most suited to decision-makers. This approach often includes scenario analysis based oil simulation with credible models as a key aspect of the learning process. Interaction among researchers, analysts and decision-makers is vital in the development of effective applications all of the players learn. Issues associated with balance between information demand and supply as well as appreciation of awareness limitations of decision-makers, analysts, and scientists are highlighted. It is argued that understanding and communicating decision risks is one of the keys to successful applications of climate prediction. We consider that advances of the future will be made by better connecting agricultural scientists and practitioners with the science of climate prediction. Professions involved in decision making must take a proactive role in the development of climate forecasts if the design and use of climate predictions are to reach their full potential. (C) 2001 Elsevier Science Ltd. All rights reserved.

Advances in forage legumes: Schrub legumes

Shelton, H.M. — 2007-08-24T00:21:07Z

Advances in understanding of enzymatic browning in harvested litchi fruit

2007-08-15T03:03:34Z

Litchi (Litchi chinensis Sonn.) is a subtropical to tropical fruit of high commercial value in international trade. However, harvested litchi fruit rapidly lose their bright red skin colour. Peel browning of harvested litchi fruit has largely been attributed to rapid degradation of red anthocyanin pigments. This process is associated with enzymatic oxidation of phenolics by polyphenol oxidase (PPO) and/or peroxidase (POD). PRO and POD from litchi pericarp cannot directly oxidize anthocyanins. Moreover, PPO substrates in the pericarp are not well characterised. Consequently, the roles of PPO and POD in litchi browning require further investigation. Recently, an anthocyanase catalysing the hydrolysis of sugar moieties from anthocyanin to anthocyanidin has been identified in litchi peel for the first time. Thus, litchi enzymatic browning may involve an anthocyanase-anthocyanin-phenolic-PPO reaction. Current research focus is on characterising the properties of the anthocyanase involved in anthocyanin degradation. Associated emphasis is on maintenance of membrane functions in relation to loss of compartmentation between litchi peel oxidase enzymes and their substrates. (C) 2004 Elsevier Ltd. All rights reserved.

Advancing modelling of leaf production by maize

Birch, C. J. og Vos, J. og Kiniry, J. R. — 2008-06-06T13:08:45Z

Advantage of single-trial models for response to selection in wheat breeding multi-environment trials

2007-08-15T05:11:11Z

An investigation was conducted to evaluate the impact of experimental designs and spatial analyses (single-trial models) of the response to selection for grain yield in the northern grains region of Australia (Queensland and northern New South Wales). Two sets of multi-environment experiments were considered. One set, based on 33 trials conducted from 1994 to 1996, was used to represent the testing system of the wheat breeding program and is referred to as the multi-environment trial (MET). The second set, based on 47 trials conducted from 1986 to 1993, sampled a more diverse set of years and management regimes and was used to represent the target population of environments (TPE). There were 18 genotypes in common between the MET and TPE sets of trials. From indirect selection theory, the phenotypic correlation coefficient between the MET and TPE single-trial adjusted genotype means [r(p(MT))] was used to determine the effect of the single-trial model on the expected indirect response to selection for grain yield in the TPE based on selection in the MET. Five single-trial models were considered: randomised complete block (RCB), incomplete block (IB), spatial analysis (SS), spatial analysis with a measurement error (SSM) and a combination of spatial analysis and experimental design information to identify the preferred (PF) model. Bootstrap-resampling methodology was used to construct multiple MET data sets, ranging in size from 2 to 20 environments per MET sample. The size and environmental composition of the MET and the single-trial model influenced the r(p(MT)). On average, the PF model resulted in a higher r(p(MT)) than the IB, SS and SSM models, which were in turn superior to the RCB model for MET sizes based on fewer than ten environments. For METs based on ten or more environments, the r(p(MT)) was similar for all single-trial models.

Adventitious root formation in cuttings of Backhousia citriodora F. Muell 1. Plant genotype, juvenility and characteristics of cuttings

2007-08-15T03:03:08Z

Backhousia citriodora is a commercially valuable Australian woody species that has a reputation for being recalcitrant in forming adventitious roots from cuttings. A study was carried out to determine whether maturation and plant genotype influenced rooting. It also tried to establish whether genotypic differences in rooting ability were related to characteristics of the cutting material. The rooting of cuttings in B. citriodora declines after maturation and is strongly influenced by genotype. The cutting characteristics of actively growing axillary buds, wide stems and mature leaves are associated with rooting and survival but not related to genotype. Furthermore, the 8-24 weeks required by B. citriodora to form roots from cuttings makes it difficult to distinguish between the characteristics that increase rooting and those characteristics that enhance survival. A subsequent disbudding experiment demonstrated that axillary buds per se have an inhibitory effect on rooting. This suggests that the presence of actively growing axillary buds are an indication of overall growth and condition of the stock plant unrelated to the formation of adventitious rooting. The effects of other cutting characteristics on rooting are also discussed. (C) 2004 Elsevier B.V. All rights reserved.

Adventitious Root Formation In Cuttings Of Backhousia citriodora F. Muell: 1 Plant Genotype, Juvenility And Characteristics Of Cuttings

2005-01-13T00:00:00Z

Backhousia citriodora is a commercially valuable Australian woody species that has a reputation for being recalcitrant in forming adventitious roots from cuttings. A study was carried out to determine whether maturation and plant genotype influenced rooting. It also tried to establish whether genotypic differences in rooting ability were related to characteristics of the cutting material. The rooting of cuttings in B. citriodora declines after maturation and is strongly influenced by genotype. The cutting characteristics of actively growing axillary buds, wide stems and mature leaves are associated with rooting and survival but not related to genotype. Furthermore, the 8 to 24 weeks required by B. citriodora to form roots from cuttings makes it difficult to distinguish between the characteristics that increase rooting and those characteristics that enhance survival. A subsequent disbudding experiment demonstrated that axillary buds per se have an inhibitory effect on rooting. This suggests that the presence of actively growing axillary buds are an indication of overall growth and condition of the stock plant unrelated to the formation of adventitious rooting. The effects of other cutting characteristics on rooting are also discussed.

Adventitious root formation in cuttings of Backhousia citriodora F. Muell 2. Seasonal influences of temperature, rainfall, flowering and auxins on the stock plant

2007-08-15T03:07:36Z

A 2-year study was carried out on established trees at two sites in southeastern Queensland, Australia, to identify environmental factors that influenced rooting of Backhousia citriodora from cuttings. Complex interactions of rainfall events above 20 mm from the preceding month and mean maximum temperature on stock plants resulted in a correlation with rooting success of r = 0.81 and 0.74 for sites at The University Of Queensland, Gatton Campus, and Cedar Glen, respectively. A more detailed investigation under controlled environmental conditions showed that maintaining stock plants at temperatures between 10 and 30degreesC had no direct effect on rooting capacity. However, temperature was correlated with growth, which may have an indirect effect on root formation. In spring floral initiation was found to only delay rooting and had no effect on the final rooting percentage. A series of seasonal experiments demonstrated that application of the auxins indole-3-acetic acid, indole-3-butyric acid and napthaleneacetic acid over a range of concentrations (1000-8000 mug/ml) did not significantly increase rooting compared to the control and there is no practical advantage in applying auxins. Seasonal results and the temperature experiment also suggest that under a glasshouse environment with higher temperatures in winter and an adequate supply of water, B. citriodora cuttings can be successfully rooted over the whole year. (C) 2004 Elsevier B.V. All rights reserved.