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Spinelli F.,University of Bologna | Noferini M.,University of Bologna | Vanneste J.L.,HortResearch | Costa G.,University of Bologna
EPPO Bulletin | Year: 2010

The electronic-nose instrumentation has advanced rapidly during the past decade, as the need for highly sensitive, fast and accurate analytical measurements have considerably stimulated the interest in developing these sensors as diagnostic tools. Given that the pathogen-induced plant responses also include changes in emission of volatiles, the electronic-nose may represent a powerful and operator-friendly alternative for rapid and reliable screening of asymptomatic plant material. In the present study, the electronic nose EOS835 (Sacmi, Imola, Italy), based on metal oxide semiconductors, was used. EOS835 was able to detect asymptomatic apple and pear plants experimentally infected with Erwinia amylovora (fire blight). The electronic nose was also successfully tested for discriminating Botrytis and Sclerotinia rots on both green and yellow kiwifruits. Even if the electronic-nose can be successfully used in experimental conditions for early diagnosis of both pre- and post-harvest diseases, its practical application in open fields, nurseries and packing houses still requires further studies. © 2010 The Authors. Journal compilation © 2010 OEPP/EPPO.

Kriticos D.J.,CSIRO | Kriticos D.J.,University of Minnesota | Kriticos D.J.,New Zealand Forest Research Institute | Leriche A.,CSIRO | And 10 more authors.
PLoS ONE | Year: 2013

Biosecurity agencies need robust bioeconomic tools to help inform policy and allocate scarce management resources. They need to estimate the potential for each invasive alien species (IAS) to create negative impacts, so that relative and absolute comparisons can be made. Using pine processionary moth (Thaumetopoea pityocampa sensu lato) as an example, these needs were met by combining species niche modelling, dispersal modelling, host impact and economic modelling. Within its native range (the Mediterranean Basin and adjacent areas), T. pityocampa causes significant defoliation of pines and serious urticating injuries to humans. Such severe impacts overseas have fuelled concerns about its potential impacts, should it be introduced to New Zealand. A stochastic bioeconomic model was used to estimate the impact of PPM invasion in terms of pine production value lost due to a hypothetical invasion of New Zealand by T. pityocampa. The bioeconomic model combines a semi-mechanistic niche model to develop a climate-related damage function, a climate-related forest growth model, and a stochastic spread model to estimate the present value (PV) of an invasion. Simulated invasions indicate that Thaumetopoea pityocampa could reduce New Zealand's merchantable and total pine stem volume production by 30%, reducing forest production by between NZ$1,550 M to NZ$2,560 M if left untreated. Where T. pityocampa is controlled using aerial application of an insecticide, projected losses in PV were reduced, but still significant (NZ$30 M to NZ$2,210 M). The PV estimates were more sensitive to the efficacy of the spray program than the potential rate of spread of the moth. Our novel bioeconomic method provides a refined means of estimating potential impacts of invasive alien species, taking into account climatic effects on asset values, the potential for pest impacts, and pest spread rates. © 2013 Kriticos et al.

Bajaj S.,ViaLactia Biosciences NZ Ltd | Puthigae S.,ViaLactia Biosciences NZ Ltd | Bryant C.,ViaLactia Biosciences NZ Ltd | Whittaker D.,ViaLactia Biosciences NZ Ltd | And 2 more authors.
Asia-Pacific Journal of Molecular Biology and Biotechnology | Year: 2010

Perennial ryegrass (Lolium perenne L.) is the most important pasture grass for meat, dairy and wool production in New Zealand, covering more than 7 million hectares. Due to its high self-incompatible nature, genetic improvement of this species has proven difficult thorough conventional breeding methods. Genomics is a tool that will help accelerate the improvements to ryegrass in traits recalcitrant to traditional conventional breeding. These traits include increased biomass, improved digestibility and enhanced drought tolerance. With this as our goal, we carried out a SAGE based transcriptome program in perennial ryegrass from livestock active paddocks and laboratory raised plants (Sathish et al., 2007). The SAGE tags were mapped to our proprietary methyl-filtered (GeneThresher®) perennial ryegrass genome sequence database. Genes and promoters were selected based on the transcriptome data and were functionally tested in transgenic rice, using the services of a commercial research lab - MetaHelix in Bangalore, India. We have identified ryegrass genes that confer increased shoot biomass in rice and ryegrass gene promoters that are constitutively expressed in transgenic rice. Leads from the functional testing are being fed into the perennial ryegrass Cisgenic® program of the Pastoral Genomics Research Consortium in New Zealand, where ryegrass may be improved using only ryegrass genetic elements, using our high-throughput Agrobacterium tumefaciens-mediated genetic transformation platform (Bajaj et al., 2006). We have also serendipitously identified a gene that improves the seed yield (but not the biomass of the plant) in rice by almost two fold. We will present the salient findings from our research in the presentation.

James H.,Sydney Postharvest Laboratory | James H.,University of Sydney | Jobling J.,University of Sydney | Tanner D.,Food Science Australia | And 2 more authors.
Acta Horticulturae | Year: 2010

Climactic conditions during two distinct periods of the growth and development of Pink Lady™ apples may be associated with the development of two expressions of flesh browning (FB) symptoms. The expression of symptoms has been linked to certain seasonal and storage conditions, growing district and several other factors have been implicated in the development of the disorder over the last two seasons. The variation between districts could be related to climatic conditions, for example low temperatures during the 50 days after full bloom growth period are speculated to increase the risk of CO 2 injury during storage as the cooler growing conditions result in more dense fruit with reduced gas diffusivity. Such fruit may accumulate high internal levels of CO2 resulting in a predisposition to develop CO2 related FB known as radial FB. Pink Lady™ apples grown in districts experiencing <1200 cumulative growing degree days from full bloom to harvest are at an increased risk of diffuse FB. Another climatic risk is if there is a low diurnal temperature variation during the 60 days prior to harvest maturity which is associated with reduced blush colour development. This situation results in growers delaying harvest in order to maximise the development of blush in order to meet strict quality guidelines designed for marketing of the cultivar under the trademark. Such fruit have an increased risk of developing both types of FB. Our results also show that the risk of developing both types of FB is higher with advanced fruit maturity at harvest. The atmospheric conditions and length of time of storage have also been shown to influence the severity of the disorder.

Varkonyi-Gasic E.,HortResearch
Methods in molecular biology (Clifton, N.J.) | Year: 2010

Plant small RNAs are a class of 19- to 25-nucleotide (nt) RNA molecules that are essential for genome stability, development and differentiation, disease, cellular communication, signaling, and adaptive responses to biotic and abiotic stress. Small RNAs comprise two major RNA classes, short interfering RNAs (siRNAs) and microRNAs (miRNAs). Efficient and reliable detection and quantification of small RNA expression has become an essential step in understanding their roles in specific cells and tissues. Here we provide protocols for the detection of miRNAs by stem-loop RT-PCR. This method enables fast and reliable miRNA expression profiling from as little as 20 pg of total RNA extracted from plant tissue and is suitable for high-throughput miRNA expression analysis. In addition, this method can be used to detect other classes of small RNAs, provided the sequence is known and their GC contents are similar to those specific for miRNAs.

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