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Aims: Two introgression lines (ILs), 182Q20 and 200A12, which had chromosomal segments introgressed from Hordeum bulbosum in H. vulgare backgrounds, were identified to show seedling resistance against Puccinia hordei, possibly attributed to two resistance genes, Rph22 and Rph26, respectively. This study characterized the phenotypic responses of the two genes against P. hordei over different plant development stages. Methods and Results: Using visual and fungal biomass assessments, responses of ILs 182Q20, 200A12 and four other barley cultivars against P. hordei were determined at seedling, tillering, stem elongation and booting stages. Plants carrying either Rph22 or Rph26 were found to confer gradually increasing resistance over the course of different development stages, with partial resistant phenotypes (i.e. prolonged rust latency periods, reduced uredinia numbers but with susceptible infection types) observed at seedling stage and adult plant resistance (APR) at booting stage. A definitive switch between the two types of resistance occurred at tillering stage. Conclusions: Rph22 and Rph26 derived from H. bulbosum were well characterized and had typical APR phenotypes against P. hordei. Significance and Impact of the Study: This study provides important insights on the effectiveness and expression of Rph22 and Rph26 against P. hordei during plant development and underpins future barley breeding programmes using non‐host as a genetic resource for leaf rust management. [ABSTRACT FROM AUTHOR]

Simple Summary: The western flower thrips (WFT) is a major glasshouse pest worldwide. Colour and odour are used to attract WFT to traps for monitoring in pest management. However, the use of colour attraction for surveillance, or its potential as a control tool for mass trapping, has not progressed due to ongoing debate about the optimal colour. Blue is commonly used for monitoring, but yellow can also be preferred over blue, confounding the implications for field application. As methodological differences amongst studies could cause this discrepancy, in the present study we evaluated populations from Germany (DE) and the Netherlands (NL) that had previously expressed different preferences for blue and yellow. Examining the behavioural response of WFT to blue or yellow LEDs in a wind tunnel by using the same methodology and facilities, the two populations maintained their original differential preferences. This remained after several generations under common conditions, although a significant increase in attraction to yellow was observed for both populations when reared on yellow-flowered chrysanthemum plants. This is the first report demonstrating that WFT populations can differ in their colour preferences even under the same experimental circumstances. Given that research is typically achieved with populations isolated from the wild for many generations, caution is still needed when extrapolating this to field situations. Discrepancies in the published research as to the attraction of the economically important pest western flower thrips (WFT) to different colours confounds the optimisation of field traps for pest management purposes. We considered whether the different experimental conditions of independent studies could have contributed to this. Therefore, the behavioural response (i.e., landings) to different colour cues of two WFT laboratory populations from Germany (DE) and The Netherlands (NL), which had previously been independently shown to have different colour preferences, were tested in the same place, and under the same experimental conditions. Single-choice wind tunnel bioassays supported previous independent findings, with more of a NL population landing on the yellow LED lamp (588 nm) than the blue (470 nm) (p = 0.022), and a not-statistically significant trend observed in a DE population landing more on blue compared to yellow (p = 0.104). To account for potential original host rearing influences, both populations were subsequently established on bean for ~20 weeks, then yellow chrysanthemum for 4–8 and 12–14 weeks and tested in wind tunnel choice bioassays. Laboratory of origin, irrespective of the host plant rearing regime, remained a significant effect (p < 0.001), with 65% of the NL WFT landing on yellow compared to blue (35%), while 66% of the DE WFT landed on blue compared to yellow (34%). There was also a significant host plant effect (p < 0.001), with increased response to yellow independent of laboratory of origin after rearing on chrysanthemum for 12–14 weeks. Results suggest that differing responses of WFT populations to colour is, in this case, independent of the experimental situation. Long-term separate isolation from the wild cannot be excluded as a cause, and the implications of this for optimising the trap colour is discussed. [ABSTRACT FROM AUTHOR]

Plants release volatiles in response to caterpillar feeding. These herbivore-induced plant volatiles (HIPVs) attract natural enemies of the herbivores and repel or attract conspecific adult herbivores in a tri-trophic interaction which has been considered to be an indirect plant defense against herbivores. Recently, we demonstrated the attraction of male and female European grapevine moth, Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) to a blend of phenylacetonitrile and acetic acid, two compounds identified as HIPVs in heterospecific apple-leafroller interactions. The ecological basis of our findings is not clearly understood. Thus, this work was undertaken to investigate HIPVs in the grapevine-leafroller interaction and study the response of heterospecific adults L. botrana, to these volatiles. We collected headspace volatiles emitted from uninfested grapevines and grapevines infested with larvae of a generalist herbivore, the grapevine leafroller moth, Sparganothis pilleriana (Denis & Schiffermüller), and analyzed them using gas chromatography/mass spectrometry. Infested grape leaves released three compounds (phenylacetonitrile, indole, and 2-phenylethanol) not found from uninfested leaves. Nine different blends, comprising a full factorial set of the three compounds with each blend containing acetic acid, were tested in a field-cagetrial. Only lures containing phenylacetonitrile caused a significant increase in trap catches compared to the other lures and blank traps. Electroantennographic tests show that L. botrana can detect the compounds. The results confirm our hypothesis that phenylacetonitrile is released during grapevines infestation with herbivores, and attracts adult L. botrana. Graphical Abstract [ABSTRACT FROM AUTHOR]

Two strains of western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), are found in New Zealand. One strain was recorded in 1934 mainly from outdoor Lupinus arboreus Sims (lupin strain, a non‐pest); the other strain was first recorded in 1992 and is found mostly on greenhouse crops (greenhouse strain, a pest). To test whether this differential pest status may be explained by different temperature requirements, a comparative life‐history study was carried out assessing the effects of temperature on life‐history traits and thermal requirements for development. Thrips strains were verified using sequence alignment of the COI gene. Thrips from each strain were fed sucrose solution and pollen, and they were reared at 8, 10, 12, 17, 22, and 27 (± 2) °C, respectively (>80% r.h., L16:D8 photoperiod). Longevity decreased with increasing temperature for both strains; however, the greenhouse strain had a significantly longer lifespan at all temperatures. Overall, the greenhouse strain laid more eggs than the lupin strain at all temperatures, with the highest mean number laid at 22 °C for the lupin strain (36.3 total eggs/female) and at 17 °C for the greenhouse strain (63.2 total eggs/female). No significant difference between the two strains was found in regards to the effect of temperature on development rate, Tmin (minimum temperature required for development), and Do (degree days). We estimated that 227 degree‐days, above a threshold temperature of 7.7 °C, were required to complete development of the greenhouse strain. No life‐history data of either strain were obtained for 8 °C as eggs did not hatch or development had not completed. The lupin strain required 261 days above 5.7 °C for complete development. The results of the study did not support the hypothesis that the lupin strain's outdoor non‐pest status was due to different temperature requirements compared with those of the greenhouse strain. [ABSTRACT FROM AUTHOR]

The effects of nitrogen on the interaction between apple trees and European canker caused by Neonectria ditissima are not well understood. Previous field and laboratory studies have shown that nitrogen affects N. ditissima disease development, germination and germ-tube growth in vitro but the type of nitrogen source has not been examined in vivo. Therefore, the aim of this study was to determine the effects of root-applied nitrogen from different sources on the development of European canker on inoculated potted trees. One-year-old 'Royal Gala' trees were planted in a low-nitrogen growth substrate and treated with a range of concentrations of calcium ammonium nitrate (CAN) or other nitrogen sources (Ca(NO3)2, KNO3, (NH4)2SO4, NH4NO3, urea, YaraMila™) at equivalent molar rates of nitrogen as the highest CAN treatment. Treatments were applied during the growing season (Nov to May). The control treatment received no applied nitrogen. Bud and leaf scar wounds were inoculated at leaf fall with N. ditissima conidia. Tree growth and health, disease progression and leaf nitrogen content were monitored. The rate of nitrogen application affected tree diameter and leaf nitrogen content while the nitrogen source mainly affected tree survival, powdery mildew incidence, leaf weights, leaf nitrogen and European canker symptom expression. Trees treated with (NH4)2SO4 had the lowest survival rates and highest leaf nitrogen content. Disease expression was highest with NH4NO3 and lowest with KNO3 applications. The control plants (which received no additional nitrogen), showed the least amount of both growth and disease expression. Applications of CAN, even at the lowest rate (20 g), increased disease susceptibility. Increasing rates of CAN applications did not significantly increase disease incidence. Nitrogen concentration is an important factor in the disease development of European canker of apple. Field evaluation is recommended to further validate these results. [ABSTRACT FROM AUTHOR]

'Lure‐and‐infect' is an insect pest management strategy with high potential but so far there are few examples of its application. Using traps as surrogates for auto‐dissemination devices, we tested the attractiveness to naturally occurring thrips (Thysanoptera: Thripidae) of three trap types differing in colour and structure, with and without the thrips lure methyl isonicotinate (MI), and sticky plate traps as a control. The aim was to find more effective traps that could be further developed into devices for auto‐dissemination and lure‐and‐infect of thrips. The number of thrips captured varied substantially with trap type and the presence of the MI lure. We found a high visual response to a sticky 'white ruffle' trap (i.e., a 30‐cm‐long cylindrical outline of folded fabric), compared to a commonly used blue sticky plate trap (Bug‐scan) as the control. This effect was seen both in a greenhouse with roses (Rosa spp.), where we encountered western flower thrips, Frankliniella occidentalis (Pergande), and in a grass field, where we encountered onion thrips, Thrips tabaci Lindeman, and New Zealand flower thrips, Thrips obscuratus (Crawford). In the absence of MI, the white ruffle trap caught 7–22× more thrips than the control Bug‐scan trap. A similarly designed blue ruffle trap and a modified Lynfield trap caught lower thrips numbers than the white ruffle and the control Bug‐scan traps. Presence of MI substantially increased the captures of T. tabaci in all three trap types in the field (2.5–18×). In the greenhouse, without MI the white ruffle trap caught 3.5–14× more thrips than the Bug‐scan, blue ruffle, or modified Lynfield traps. Presence of MI increased the captures of F. occidentalis males and females in the Lynfield and blue ruffle traps (1.4–2.8×), but not in the white ruffle trap in the greenhouse (ca. 1.1×). The importance of visual and olfactory factors for the design of effective auto‐dissemination and lure‐and‐infect strategies for thrips management is discussed. [ABSTRACT FROM AUTHOR]

Molecular detection of phytopathogens is increasingly being applied to identify regulated organisms at the border in many parts of the world. However, even with molecular tests, complete phenotyping and identification of a strain is often time consuming and sometimes inconclusive. In this study, a leaf‐based pathogenicity test was used to separate pseudomonads into two groups, Group A containing pathogens, and Group B containing saprotrophs. Comparative genomics of 56 pseudomonad genomes from different plant hosts (including 29 strains from kiwifruit) agreed with kiwifruit pathogenicity test results, placing pathogens into Group A and saprotrophs into Group B. Sixteen loci were found unique to Group A. A PCR assay was developed for amplification of one of these loci, the trehalose phosphatase gene. The generation of this 655 bp amplicon was associated with production of water‐soaked lesions on inoculated kiwifruit leaves by pseudomonads in Group A. This test was validated for further strains from all seven pathogenic Pseudomonas phylogroups, non‐pathogenic pseudomonads, and other bacterial genera. The sensitivity of the PCR was comparable to the limit of recovery of pseudomonads by culturing. This simple PCR assay could be used as part of a testing pipeline at the border and for general surveillance for screening plants with and without symptoms, offering the potential to detect uncharacterized pseudomonads that may pose a biosecurity risk. The method was shown to be able to rapidly identify pathogens cultured from plant material with symptoms, or, more importantly, to detect pathogens directly from plant tissue. [ABSTRACT FROM AUTHOR]

Real-time quantitative PCR assay targeting a 16S-23S intergenic space region sequence is designed for measuring the sizes of populations of Lactobacillus salivarius present in ileal digesta collected from broiler chickens. Stocking densities have not affected the numbers of Lactobacillus salivarius cells in the ileum, whereas a diet containing meat and bone meal has reduced the size of the Lactobacillus salivarius populations relative to that of chickens given the controlled diet.

Knowledge about the behaviour of passive dispensers used to release semiochemicals for insect pest management is essential to ensure the efficacy of monitoring and control methods based on the use of the semiochemicals. The release characteristics of different passive dispenser types (commercial sachet, altered commercial sachet, polyethylene bags and cotton rolls) were investigated in the laboratory under various conditions. Using the volatile compound methyl isonicotinate (MI), a known lure for western flower thrips Frankliniella occidentalis (Pergande) and two additional homologues ethyl and n-propyl isonicotinate the effect of loading amount (0.5, 1.0 or 2.5 ml), temperatures (15°C, 25°C or 35°C) and air flow (0.1–0.15 m/s or 0.25–0.3 m/s) were tested in a low-speed laminar-flow wind tunnel. The results showed zero-order release kinetics for all tested dispenser types. Release rate kinetics relies on the type of molecule, dispenser type, and the climatic conditions with temperature being a major determinant of release rate. The results of the release characteristics of the different dispensers are discussed in regards to their practical use under greenhouse and field conditions. [ABSTRACT FROM AUTHOR]

BACKGROUND: Management of tomato potato psyllid (TPP; Bactericera cockerelli (Šulc)) predominantly relies on insecticides. However, biological control agents (BCAs) could provide viable alternatives to suppress TPP populations. In this laboratory experiment, we assessed the predatory mite Amblydromalus limonicus (Garman & McGregor) as a BCA of TPP on whole plants of two tomato and two pepper cultivars over a 5‐week period. RESULTS: Plant species and cultivar had a significant effect on the ability of A. limonicus to suppress populations of TPP. Numbers of TPP were suppressed by A. limonicus on four pepper treatments, but on only one tomato treatment. Amblydromalus limonicus could survive and reproduce on pepper and tomato, but more were found on pepper at the end of the 5‐week period. CONCLUSION: Amblydromalus limonicus has the potential to suppress TPP populations on pepper but not tomato cultivars, based on the present study. Possible reasons for these results include the difference in leaf morphology between species, and higher predator:prey ratios on pepper than tomato because of the longer TPP generation time on pepper. © 2018 Society of Chemical Industry The predatory mite Amblydromalus limonicus established on both pepper and tomato plants infested with Bactericera cockerelli (TPP), but may only provide suppression of TPP on pepper plants but not tomato plants. [ABSTRACT FROM AUTHOR]

Captan (a trichloromethyl sulfenyl fungicide) is commonly used for control of Neonectria ditissima in apple. In New Zealand, picking and leaf scars are the main source of new infections. The captan concentrations required for wound protection of leaf scars, picking and rasp wounds was determined in planta. Fresh wounds, inoculated with N. ditissima, were sprayed with captan using a motorised knapsack (leaf scars) or hand-held spray bottles targeting the wound area (picking and rasp wounds). Captan concentrations ranged from 0 to 400% field rate (100% = 2 kg captan/ha). Wounds were sampled pre- and post-captan application for residue analyses and the remainder assessed regularly in the field for disease expression. Disease development decreased as captan concentrations increased. Approximately 2 μg captan/scar (100% field rate) was required to protect leaf scars. Four times the field rate of captan was needed for a 55 and 70% disease reduction on picking and rasp wounds, respectively. Label-rate applications of captan controlled low incidence of N. ditissima leaf-scar infections in the field in autumn, but disease control of picking scars and other large wounds might be difficult to achieve. [ABSTRACT FROM AUTHOR]

Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker of kiwifruit, currently the most important disease of Actinidia species worldwide. Due to the risk of Psa being associated with plant material moved from Psa-affected regions, there is a need to understand the behaviour and survival of Psa within tissue cultured plants, and identify detection or intervention points within the propagation process. In this study, we evaluate the ability of Psa to grow on plant culture media, assess the movement of Psa within in vitro growing plants, investigate the detection threshold of Psa and model the likelihood of false negatives when screening for Psa. Following inoculation of in vitro growing plants, even of genotypes considered Psa resistant, the bacteria spread rapidly through growing shoots. Standard plant tissue culture media did not support easily visible growth of Psa, however, supplementing these with peptone promoted Psa growth, providing a rapid, non-destructive visual indicator of its presence. [ABSTRACT FROM AUTHOR]

Invasions by insects introduced via international trade continue to cause worldwide impacts. Surveillance programs using traps baited with host volatiles and pheromones can detect incursions of nonnative species. We report on two experiments executed to determine if attractants for several insect species can be combined without compromising trap catches and detection ability of target species. In the first experiment, we tested the effect of bark beetle pheromones (plus α-pinene) and trap contact with foliage on trap catches of the brown marmorated stink bug Halyomorpha halys Stål (Hemiptera: Pentatomidae) in traps baited with a mixture of bisabolenes and methyl (E,E,Z)-2,4,6-decatrienoate. Trap capture of H. halys adults was greater in traps not in contact with foliage, and the bark beetle pheromones ipsenol and ipsdienol did not affect trap capture of H. halys. In the second experiment, we tested the effects of multi-lure interactions among the primary host attractants α-pinene and ethanol, and the pheromones monochamol, ipsenol, ipsdienol, lanierone, and the H. halys compounds, on trap captures of various forest and agricultural insect pests. Specifically, we targeted Monochamus spp. (Coleoptera: Cerambycidae), Ips spp. (Coleoptera: Scolytinae) and H. halys. We found that a combination of all lures did not catch significantly lower numbers of Monochamus carolinensis Olivier, Monochamus scutellatus Say (Coleoptera: Cerambycidae), and Ips pini Say (Coleoptera: Scolytidae) than lure combinations missing components although removal of both lanierone and ipsdienol somewhat increased catches of Ips grandicollis Eichhoff (Coleoptera: Curculionidae). Our results support the use of traps baited with a full combination of these attractants in surveillance programs. This should reduce costs and increase detection rates of a wider range of conifer forest pests and H. halys. [ABSTRACT FROM AUTHOR]

Brassica napus and Brassica rapa are grown across six continents for purposes including oilseed, biofuel, vegetables and livestock fodder. Hybridisation between the two can downgrade seed quality reducing grower returns. We assess the similarity of flower visitor assemblages of both species to determine the applicability of pollinator management strategies to both. Insect taxa were collected using window traps placed within ten peak- flowering fields, five each of B. napus and B. rapa (one cultivar/species) located in South Canterbury, New Zealand. Both crops contained similar flower visitor assemblages with 25 of 29 taxa in common. Of the 1549 insects counted, Apis mellifera was most abundant (~40% of individuals in both crops). Bombus terrrestris and the flies Delia platura, and Oxysarcodexia varia were also common. Crop location more likely influenced assemblage composition than crop species. Strategies to boost the role of bee and non-bee pollinators have potential benefits for both crops; however, a broader understanding of pollinator movement between crops is required to optimise seed purity and crop spacing. [ABSTRACT FROM AUTHOR]

Fresh, wild-type conidium suspensions of Neonectria ditissima prepared from sporulating European canker lesions for use in field inoculation trials are not always readily available. The effect of freezing inoculum on the viability of spores and their ability to cause infection in situ was assessed using 15-19 frozen N. ditissima conidium suspensions during 2015-2017. Freshly prepared inoculum and water only were used to inoculate rasp wounds on 'Braeburn' (2015), 'Scilate'/Envy™ (2016) and 'Royal Gala' and 'Braeburn' (2017) along with frozen inoculum ranging in age from 1-462 days at concentrations >104 conidia/mL. Lesion development was assessed at approximately monthly intervals. In all experiments, there was no substantial effect of storage time on lesion development although germination in droplets may have decreased during storage. As expected, there was a cultivar effect (2017 data only), with fewer lesions on 'Braeburn' compared with 'Royal Gala'. Long-term deep- freeze storage up to 462 days of N. ditissima conidium suspensions (>104 conidia/mL) did not affect the ability of spores to infect apple trees. Therefore, spore suspensions can be batch-prepared and stored frozen for future experimental use. [ABSTRACT FROM AUTHOR]

Background: Although starch consists of large macromolecules composed of glucose units linked by α-1,4-glycosidic linkages with α-1,6-glycosidic branchpoints, variation in starch structural and functional properties is found both within and between species. Interest in starch genetics is based on the importance of starch in food and industrial processes, with the potential of genetics to provide novel starches. The starch metabolic pathway is complex but has been characterized in diverse plant species, including pea. Results: To understand how allelic variation in the pea starch metabolic pathway affects starch structure and percent amylose, partial sequences of 25 candidate genes were characterized for polymorphisms using a panel of 92 diverse pea lines. Variation in the percent amylose composition of extracted seed starch and (amylopectin) chain length distribution, one measure of starch structure, were characterized for these lines. Association mapping was undertaken to identify polymorphisms associated with the variation in starch chain length distribution and percent amylose, using a mixed linear model that incorporated population structure and kinship. Associations were found for polymorphisms in seven candidate genes plus Mendel's r locus (which conditions the round versus wrinkled seed phenotype). The genes with associated polymorphisms are involved in the substrate supply, chain elongation and branching stages of the pea carbohydrate and starch metabolic pathways. Conclusions: The association of polymorphisms in carbohydrate and starch metabolic genes with variation in amylopectin chain length distribution and percent amylose may help to guide manipulation of pea seed starch structural and functional properties through plant breeding. [ABSTRACT FROM AUTHOR]

Lr34 is an important adult plant resistance gene that is effective against a number of wheat (Triticum aestivum L.) diseases and has proved durable for over 100 yr. However, the energy requirements of Lr34 resistance, combined with the pleiotrophic effect of leaf tip necrosis, can result in reduced yield potential. To evaluate the absence of Lr34 from elite breeding material, a cross was made between similar-yielding, milling wheat cultivars 'Conquest' (Lr34sus) and 'Bakker Gold' (Lr34res). Independent lines were carried forward and, at the F4 stage, sister pairs were selected for the different homozygous alleles of the marker csLV34, corresponding to Lr34res or Lr34sus. These lines were further selfed to produce nine stable F8 pairs (Lr34res and Lr34sus) for field trialing and evaluation over 3 yr under a range of fungicide treatments. In the absence of fungicide and with natural infections of stripe rust (Puccinia striiformis f.sp. tritici) and leaf rust (Puccinia triticina), Lr34res lines had lower disease severity, increased total yield, and better grain quality than Lr34sus lines. This pattern was reversed under full fungicide control, as Lr34sus lines displayed higher mean plot yield (2010: +4.3%, p < 0.001; 2012: +4.4%, p < 0.001) and possessed superior grain quality data than the Lr34res lines. The high-yield, high-input farming environment and the use of full fungicide control in New Zealand's current wheat cultivar trialing system means that genetic sources of rust resistance such as Lr34 provide little or no competitive advantage. [ABSTRACT FROM AUTHOR]

Amblydromalus limonicusconsumed fewer first instarFrankliniella occidentalisthrips thanBactericera cockerellipsyllids per day when on the same (1.7 thrips, 3.7 psyllids) or separate (2.9 thrips, 4.4 psyllids) capsicum leaf discs. Mites ate fewer psyllids per day on tomato (1.9) than on capsicum (3.1). Mite survival was similar on both prey and plants. [ABSTRACT FROM PUBLISHER]

The present study compared different adhesives for trapping efficacy, ease of removing specimens and the subsequent quality of specimens for identification of thrips pests captured on blue plastic boards in a commercial capsicum glasshouse. The mean total number of thrips caught on sticky boards differed significantly with different adhesives. Blue boards covered with a water-based adhesive caught the least total number of thrips in the two experiments (56 thrips per trap, experiment 1; 4 thrips per trap, experiment 2). Traps covered with Stikem Special ® caught the greatest number of total thrips (299 per trap, experiment 1; 32 per trap, experiment 2). De-Solv-it ® was the most effective solvent to remove thrips from sticky boards compared with water and mineral oil, with all thrips detached from boards for all adhesive treatments within 150 min. Damage to or absence of key morphological features due to removal of specimens with De-Solv-it that would prevent species identification was recorded in only 10 of the 720 specimens removed from traps across all adhesives. The majority of thrips (70–92%) identified were Thrips tabaci Lindeman or Frankliniella occidentalis (Pergande). The type of adhesive used is an important factor to consider when developing traps for insect pest monitoring and management. [ABSTRACT FROM AUTHOR]

Starch phosphorylation is an important aspect of plant metabolism due to its role in starch degradation. Moreover, the degree of phosphorylation of starch determines its physicochemical properties and is therefore relevant for industrial uses of starch. Currently, starch is chemically phosphorylated to increase viscosity and paste stability. Potato cultivars with elevated starch phosphorylation would make this process unnecessary, thereby bestowing economic and environmental benefits. Starch phosphorylation is a complex trait which has been previously shown by antisense gene repression to be influenced by a number of genes including those involved in starch synthesis and degradation. We have used an association mapping approach to discover genetic markers associated with the degree of starch phosphorylation. A diverse collection of 193 potato lines was grown in replicated field trials, and the levels of starch phosphorylation at the C6 and C3 positions of the glucosyl residues were determined by mass spectrometry of hydrolyzed starch from tubers. In addition, the potato lines were genotyped by amplicon sequencing and microsatellite analysis, focusing on candidate genes known to be involved in starch synthesis. As potato is an autotetraploid, genotyping included determination of allele dosage. Significant associations (p < 0.001) were found with SNPs in the glucan water dikinase (GWD), starch branching enzyme I (SBEI) and the starch synthase III (SSIII) genes, and with a SSR allele in the SBEII gene. SNPs in the GWD gene were associated with C6 phosphorylation, whereas polymorphisms in the SBEI and SBEII genes were associated with both C6 and C3 phosphorylation and the SNP in the SSIII gene was associated with C3 phosphorylation. These allelic variants have potential as genetic markers for starch phosphorylation in potato. [ABSTRACT FROM AUTHOR]

Background Non-structural carbohydrate ( NSC; glucose, fructose, sucrose and fructan) composition of onions ( Allium cepa L.) varies widely and is a key determinant of market usage. To analyse the physiology and genetics of onion carbohydrate metabolism and to enable selective breeding, an inexpensive, reliable and practicable sugar assay is required to phenotype large numbers of samples. Results A rapid, reliable and cost-effective microplate-based assay was developed for NSC analysis in onions and used to characterise variation in tissue hexose, sucrose and fructan content in open-pollinated breeding populations and in mapping populations developed from a wide onion cross. Sucrose measured in microplates employing maltase as a hydrolytic enzyme was in agreement with HPLC-PAD results. The method revealed significant variation in bulb fructan content within open-pollinated 'Pukekohe Longkeeper' breeding populations over a threefold range. Very wide segregation from 80 to 600 g kg−1 in fructan content was observed in bulbs of F2 genetic mapping populations from the wide onion cross 'Nasik Red × CUDH2150'. Conclusion The microplate enzymatic assay is a reliable and practicable method for onion sugar analysis for genetics, breeding and food technology. Open-pollinated onion populations may harbour extensive within-population variability in carbohydrate content, which may be quantified and exploited using this method. The phenotypic data obtained from genetic mapping populations show that the method is well suited to detailed genetic and physiological analysis. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Light brown apple moth [Epiphyas postvittana (Walker)] is now established as an economic and quarantine pest in California, and new technologies are being investigated to increase options for its management. Two new organic formulations for mating disruption, SPLAT LBAM HD-0 and organic Hercon Biotie (biodegradable) were field tested at four point source densities (25, 72, 322, and 500/ha) and compared with the standard Isomate LBAM Plus (500/ha, as a positive control) and an untreated (negative) control. Assessment involved trapping using synthetic lures and virgin females. In total, 175,776 male light brown apple moths were caught to both the caged females and synthetic lures, from 10 February to 19 May 2011. The light brown apple moth catch dramatically decreased from baseline measurements after the treatments were applied, with the highest density treatments reducing catch to below 10% of the catch in the untreated controls within the first week (>90% disruption). In synthetic lure traps, the SPLAT and Biotie treatment performed similarly well over all rates (P = 0.317 for posttreatment percentage communication disruption), but SPLAT performed better at disrupting virgin female traps (P = 0.045). There was a significant increase in disruption with an increasing number of points/ha (P < 0.001). Disruption of communication was similar for all three technologies (SPLAT, Biotie and Isomate) at 500 points/ha for both types of trap (P > 0.74). Disruption of this species in vineyards is thus highly feasible. [ABSTRACT FROM AUTHOR]

The radiation biology of two geographically isolated populations of the light brown apple moth [Epiphyas postvittana (Walker)] was studied in Australia and New Zealand as an initiation of a SIT/F1 sterility program. Pharate and ≤ 2 d pre-emergence pupae were exposed to increasing radiation doses up to a maximum dose of 300 Gy. Fertility and other life history parameters were measured in emerging adults (parental) and their progeny (F1-F3 adults). Parental fecundity was significantly ,affected by increasing irradiation dose in pharate pupae only. For both populations, parental egg fertility declined with increasing radiation. This was most pronounced for the irradiated parental females whose fertility declined at a higher rate than of irradiated males. At 250 Gy, females ≤ 2 d preemergence pupae produced few larvae and no adults at F No larvae hatched from 250 Gy-irradiated female pharate pupae. At 300 Gy, males still had residual fertility of 2-5.5%, with pharate pupae being the more radio-sensitive. Radiation-induced deleterious inherited effects in offspring from irradiated males were expressed as increased developmental time in F larvae, a reduction in percent F1 female survival, decreased adult emergence and increased cumulative mortality over subsequent generations. Males irradiated at ≥150 Gy produced few but highly sterile offspring at F1 and mortality was >99% by F2 egg. [ABSTRACT FROM AUTHOR]

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A study was undertaken to determine whether Scolypopa australis, the passionvine hopper, communicates using substrate-borne vibrations, as its use of such signals for communication is currently unknown. This insect is a costly pest to the kiwifruit industry in New Zealand, where few pest management tools can be used during the growing season. Vibrations emitted by virgin females and males of S. australis released alone on leaves of Griselinia littoralis were recorded with a laser vibrometer to identify and characterise potential spontaneous calling signals produced by either sex. In addition to single-insect trials, preliminary tests were conducted with female–male pair trials to determine whether individuals exchanged signals. The signal repertoire of S. australis includes a male calling signal and two female calling signals. However, no evidence of duetting behaviour that is potentially necessary for pair formation has been found to date. Our outcome suggests that a deeper understanding of the role of vibrational communication employed by S. australis is needed, and by disclosing the pair formation process, a new residue-free pest management tool against this pest may be developed. In addition, this vibration-based tool could contribute to future biosecurity preparedness and response initiatives. [ABSTRACT FROM AUTHOR]

Two field experiments examined the distance over which an attractant odour of a volatile chemical could influence thrips capture in proximal traps that were without the odour. In each experiment a star-shaped array of water traps consisted of a centre trap with or without an odour surrounded by odourless traps at 0.5, 1, 2, 5, and 10 m in eight equally spaced radial arms 45° apart. Experiments ran for 47 h (centre trap: ethyl nicotinate) or 7 h (centre trap: ethyl isonicotinate). Each had four replicates. With ethyl nicotinate, more thrips were trapped in the centre-baited traps than in the unbaited centre traps (63×, 7×, 98× and 200× for total thrips, Thrips tabaci Lindeman ♀, and Thrips obscuratus Crawford ♀and ♂, respectively) (Thysanoptera: Thripidae). More total thrips and T. tabaci♀ were trapped in the centre traps baited with ethyl isonicotinate than in unbaited centre traps (21× for both). For ethyl nicotinate, numbers of T. obscuratus in unbaited traps downwind from the baited centre trap declined by 50% within 0.4 m (♀) and 2 m (♂) and by 95% within 3 m (both ♀ and ♂) based on model predictions. For ethyl isonicotinate, numbers of T. tabaci in unbaited traps downwind from the baited centre trap declined by 50% within 1.3 m and by 95% within 10 m based on model predictions. Wind direction was an important factor in the degree and direction of thrips capture with the highest thrips capture downwind from the centre trap with odour. There was no increase in numbers of T. tabaci in any traps without odour in the ethyl nicotinate-centred array. Differences in trapping patterns between thrips species and odours indicated that there were thrips species–odour specific interactions. Experiments examining differences between traps with and without a thrips attractant odour need to be designed very carefully to ensure meaningful results especially in enclosed and/or low-wind indoor situations. [ABSTRACT FROM AUTHOR]

Abstract: The effects of starvation or age on the walking or flying response of female Frankliniella occidentalis to visual and/or odor cues in two types of olfactometer were examined in the laboratory. The response of walking thrips starved for 0, 1, 4, or 24h to an odor cue (1μl of 10% p-anisaldehyde) was examined in a Y-tube olfactometer. The take-off and landing response of thrips (unknown age) starved for 0, 1, 4, 24, 48 or 72h, or of thrips of different ages (2–3 days or 10–13 days post-adult emergence) starved for 24h, to a visual cue (98cm2 yellow sticky trap) and/or an odor cue (0.5 or 1.0ml p-anisaldehyde) was examined in a wind tunnel. More thrips walked up the odor-laden arm in the Y-tube when starved for at least 4h (76%) than satiated thrips (58.7%) or those starved for 1h (62.7%, P<0.05). In the wind tunnel experiments the percentage of thrips to fly or land on the sticky trap increased between satiated thrips (7.3% to fly, 3.3% on trap) and those starved for 4h (81.2% to fly, 29% on trap) and decreased between thrips starved for 48 (74.5% to fly, 23% on trap) and 72h (56.5% to fly, 15.5% on trap, P<0.05). Fewer younger thrips (38.8%) landed on a sticky trap containing a yellow visual cue of, those that flew, than older thrips (70.4%, P<0.05), although a similar percentage of thrips flew regardless of age or type of cue present in the wind tunnel (average 44%, P>0.05). [Copyright &y& Elsevier]

This paper reviews current methods for fitting a range of models to censored seed germination data and recommends adoption of a probability-based model for the time to germination. It shows that, provided the probability of a seed eventually germinating is not on the boundary, maximum likelihood estimates, their standard errors and the resultant deviances are identical whether only those seeds which have germinated are used or all seeds (including seeds ungerminated at the end of the experiment). The paper recommends analysis of deviance when exploring whether replicate data are consistent with a hypothesis that the underlying distributions are identical, and when assessing whether data from different treatments have underlying distributions with common parameters. The inverse normal distribution, otherwise known as the inverse Gaussian distribution, is discussed, as a natural distribution for the time to germination (including a parameter to measure the lag time to germination). The paper explores some of the properties of this distribution, evaluates the standard errors of the maximum likelihood estimates of the parameters and suggests an accurate approximation to the cumulative distribution function and the median time to germination. Additional material is on the web, at. [ABSTRACT FROM AUTHOR]