12 research outputs found

    Open field trial of genetically modified parthenocarpic tomato: seedlessness and fruit quality

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    BACKGROUND: Parthenocarpic tomato lines transgenic for the DefH9-RI-iaaM gene have been cultivated under open field conditions to address some aspects of the equivalence of genetically modified (GM) fruit in comparison to controls (non-GM). RESULTS: Under open field cultivation conditions, two tomato lines (UC 82) transgenic for the DefH9-RI-iaaM gene produced parthenocarpic fruits. DefH9-RI-iaaM fruits were either seedless or contained very few seeds. GM fruit quality, with the exception of a higher ÎČ-carotene level, did not show any difference, neither technological (colour, firmness, dry matter, °Brix, pH) nor chemical (titratable acidity, organic acids, lycopene, tomatine, total polyphenols and antioxidant capacity – TEAC), when compared to that of fruits from control line. Highly significant differences in quality traits exist between the tomato F1 commercial hybrid Allflesh and the three UC 82 genotypes tested, regardless of whether or not they are GM. Total yield per plant did not differ between GM and parental line UC 82. Fruit number was increased in GM lines, and GM fruit weight was decreased. CONCLUSION: The use in the diet of fruits from a new line or variety introduces much greater changes than the consumption of GM fruits in comparison to its genetic background. Parthenocarpic fruits, produced under open field conditions, contained 10-fold less seeds than control fruits. Thus parthenocarpy caused by DefH9-RI-iaaM gene represents also a tool for mitigating GM seeds dispersal in the environment

    Deep learning can be used to classify and segment plant cell types in xylem tissue

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    Studies of plant anatomical traits are essential for understanding plant physiological adaptations to stressful environments. For example, shrubs in the chaparral ecosystem of southern California have adapted various xylem anatomical traits that help them survive drought and freezing. Previous studies have shown that xylem conduits with a narrow diameter allows certain chaparral shrub species to survive temperatures as low as -12 C. Other studies have shown that increased cell wall thickness of fibers surrounding xylem vessels improves resistance to water stress-induced embolism formation. Historically, these studies on xylem anatomical traits have relied on hand measurements of cells in light micrographs, but this approach is time- and labor-intensive. Here we propose that deep learning-based models can be used to rapidly detect, classify, and measure plant cells with high precision and accuracy. Our goal was to develop models that can detect and classify plant cell types with greater than 95% accuracy. In this project, we constructed a deep convolutional neural network (DCNN) to segment and classify cell types in light micrographs. We created an encoder-decoder U-Net architecture, where we used convolutional layers to encode the features of the cross section, and transposed convolutional layers to upscale the features to a vessel segmentation mask. We interleaved batch normalization and max pooling layers inside the encoder-decoder blocks to provide a strong regularization to the U-Net. For classification, we explored various transformers and convolutional neural networks to achieve a cell type classification accuracy of 98.1%. The testing samples were isolated from the training data, and our DCNN performed vessel segmentation on this dataset with high pixel classification accuracy (97.05%) and excellent precision score (80.71%) that represents the model’s ability to predict positive vessel-class pixel values. With further development, the DCNN may provide the ability to measure vessel thickness and area, while also potentially measuring vessel cell wall thickness by performing a digital subtraction of a cell wall mask and vessel mask. This approach could provide opportunities to rapidly analyze larger plant anatomy datasets, allowing us to scale up questions relating plant xylem structure and function to the level of ecosystems or the globe

    Isolating the impact of antipsychotic medication on metabolic health : secondary analysis of a randomized controlled trial of antipsychotic medication versus placebo in antipsychotic medication naïve first‐episode psychosis (the STAGES study)

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    Background Cardiovascular and metabolic diseases are the leading contributors to the early mortality associated with psychotic disorders. To date, it has not been possible to disentangle the effect of medication and non-medication factors on the physical health of people with a first episode of psychosis (FEP). This study aimed to isolate the effects of antipsychotic medication on anthropometric measurements, fasting glucose and lipids. Methods This study utilized data from a triple-blind randomized placebo-controlled trial comparing two groups of antipsychotic-naĂŻve young people with a FEP who were randomized to receive a second-generation antipsychotic medication (FEP-medication group) or placebo (FEP-placebo group) for 6 months. Twenty-seven control participants were also recruited. Results Eighty-one participants commenced the trial; 69.1% completed at least 3 months of the intervention and 33.3% completed the full 6 months. The FEP-placebo group gained a mean of 2.4 kg (±4.9) compared to 1.1 kg (±4.9) in the control participants (t = 0.76, p = .45). After controlling for multiple analyses, there was no difference in blood pressure, waist circumference or heart rate between the FEP-placebo group and controls. After 6 months, the FEP medication group had gained 4.1 kg (±4.5), higher than those receiving placebo but not statistically significant (t = 0.8, p = .44). There were no differences in fasting glucose or lipids between the FEP groups after 3 months. Conclusions While limited by small numbers and high attrition, these findings indicate that some of the metabolic complications observed in psychotic disorders could be attributable to factors other than medication. This emphasizes the need to deliver physical health interventions early in the course of FEP

    Quality and nutritional value in strawberry breeding and cultivar evaluation

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    Nutritional attributes like antioxidant activity (AA) and total phenolic content and fruit quality attributes including firmness, colour, soluble solids (SS) content and titratable acidity (TA) were determined for strawberry cultivars, selections and seedlings. The TEAC (Trolox Equivalent Antioxidant Analysis) method has been used to assess the AA of cultivars (ranged from 12.12 mumol TE/g FW to 20.50 mumol TE/g FW). Correlation between nutritional attributes TEAC and total phenolic content was found (data not shown). Quality attributes such as soluble solid content and the titratable acidity concentration, in particular their ratio (SS/TA), are important to show how a fruit is balanced (ratio = 1). Our results demonstrate a high variability in quality and nutritional attributes among strawberry cultivars and that these characters can be combine

    Study on adaptability of blueberry cultivars in center south Europe

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    The European countries have significantly different climates, growing conditions and consumer requirements for berry fruit. The increased demand of blueberry fruit and the consequent cultivation areas is limited by the reduced adaptability of cultivars to different soils and climates. The present study describes the field evaluation of nineteen Vaccinium genotypes (cultivars and selections). The combination of genotypes includes commercial varieties (cultivars) and new breeding lines (selections) released by the New Zealand Institute for Plant & Food Research Ltd. breeding program. For all the genotypes data were collected for two years (2012 and 2013) and included: total plant yield, fruit size, soluble solid content, titratable acidity and phytochemical compounds. Results from this study have demonstrated that none of the genotypes had the best of all traits, however, some adapted to the growing conditions and climat

    Protective nets reduce pollen flow in blueberry orchards

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    Protective covers are commonly employed in agricultural systems to reduce the impacts of extreme weather events, pest species and to control the environmental conditions in which crop plants are grown. As protected cropping systems are expanding rapidly, there is an urgent need to better understand how variations in netting practices might impact pollination service delivery by wild and managed insects to pollinator dependent crops. We used southern highbush blueberry (Vaccinium corymbosum L. interspecific hybrid) crops to investigate (i) how variations in protected cropping structures (fully netted, partially netted and unnetted blocks) influence the amount and composition of pollen deposited on crop stigmas; (ii) to what extent blueberry floral abundance and plant richness in remnant vegetation influence pollen composition on crop stigmas; and (iii) the difference between stigmatic pollen load composition in the middle and at the edge of crop blocks. We collected data from 15 field blocks of 6 different cultivars distributed on 10 farms. We collected blueberry stigmas to analyse the pollen load and measured blueberry floral abundance and richness of flowering plant taxa in remnant vegetation every two weeks. Our results indicate that blueberry pollen abundance on stigmas was reduced by up to 81% under full netting and 36% by partial netting. On blueberry stigmas, we identified a total of 31 morphospecies of non-blueberry pollen from 20 plant families. There was no relationship between blueberry stigmatic pollen loads and blueberry floral abundance. Moreover, the composition of non-blueberry pollen on stigmas differed between blueberry blocks under different netting categories. However, there was no relationship between plant taxa present in the surrounding remnant vegetation of each block and the pollen load on the stigmas of each block. Combining all netting treatments, stigmas located at the edge of the blocks received a greater amount of both conspecific (5% more) and heterospecific (40% more) pollen grains than those within the middle of blocks. Pollen flow in fields is reduced under netting structures as well as in the middle of blocks. Reduced blueberry pollen flow under nets may be detrimental to fruit yield and quality for some varieties of pollinator dependent crops, particularly those that are self-incompatible

    Self‐compatible blueberry cultivars require fewer floral visits to maximize fruit production than a partially self‐incompatible cultivar

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    Effective pollination is a complex phenomenon determined by the outcome of the interaction between pollen transfer and a plants' pollinator dependency, yet most studies investigate pollinator effectiveness without consideration of plant mating system differences. We investigated pollinator effectiveness in three types of blueberry that differed in their degree of pollinator dependency as measured by plant mating system: two self-compatible highbush cultivars and one partially self-incompatible rabbiteye cultivar. We quantified pollinator effectiveness as a function of the fruit set and fruit weight resulting from single and multiple floral visits (2–15 visits), in comparison with estimates of fruit set and fruit weight resulting from experimental pollination treatments (open-pollination, cross-pollination and self-pollination). Single-visit effectiveness of fruit set was similar across pollinator taxa but considerably higher in both self-compatible cultivars. The probability of fruit set in all three blueberry types improved in response to an increasing number of visits, but this relationship was steeper in self-compatible cultivars: >90% probability of fruit set was achieved in three to five visits. In the self-incompatible rabbiteye cultivar, 58% fruit set was achieved with 15 visits. Multiple visits improved fruit weight by 27%–48% in self-compatible cultivars, but there was no relationship in rabbiteye. Pollination deficits in fruit set and fruit weight due to self-pollination were most pronounced in rabbiteye. Synthesis and applications. Improved understanding of cultivar-level mating system differences in plants will inform pollination planning and management in agroecosystems. Self-compatible (highbush) cultivars require less floral visitation to maximize fruit production. Therefore, these cultivars may be best suited to landscapes in which pollinator abundance is low, such as intensive and/or simple landscapes. In contrast, self-incompatible (rabbiteye) cultivars may benefit from the implementation of mixed-cultivar crop row plantings to facilitate cross-pollination
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