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  • Author or Editor: Donald Walters x
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Anthocyanins (Acy) in ripening blueberry fruit of the cv. Wolcott were identified and their amounts estimated spectrophotometrically. Fifteen Acy, all combinations of Mv, Pt, Pn, Dp, and Cy with glu, gal, or arab4 in the 3-position were found in unripe, red fruit. Ripe and overripe fruit contained all these Acy except Pn-gal. Cy-glu and Cy-gal comprised about 40% of the total Acy in unripe fruit, while Mv-glu and Mv-gal constituted about 60% in the overripe fruit. The relative proportions of 3-glucosides, 3-galactosides, and 3-arabinosides remained fairly constant throughout fruit ripening.

Open Access

Diploid zonal geraniums (Pelargonium ×hortorum) are able to resist attack by small arthropod pests such as the two-spotted spider mite (Tetranychus urticae Koch) when exudate produced by tall glandular trichomes contains a high percentage of ω5-unsaturated anacardic acids. Trichomes of susceptible plants exude primarily saturated anacardic acids. Inbred mite-resistant and -susceptible geraniums were reciprocally crossed and the F1, F2, and backcross generations were examined for anacardic acid composition and trichome density. Selected F2 plants were bioassayed for resistance to two-spotted spider mites. High concentrations of ω5-unsaturated anacardic acids in resistant plants are conditioned by a single dominant allele. We propose that inheritance of tall glandular trichome density can be controlled by a small number of loci (possibly as few as one) exhibiting codominance. F2, with low densities of tall glandular trichomes and producing ω5-unsaturated anacardic acids, displayed effective resistance to two-spotted spider mites as measured by mite mortality and fecundity. A genetic model for the biosynthesis of anacardic acids is proposed.

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Databases are commonly used to coordinate and summarize research from multiple projects. The potato (Solanum tuberosum) research community has invested significant resources in collecting data from multiple states and provinces, and we have developed a web-based database format for the use of researchers, farmers, and consumers. The northeast regional potato variety development project (NE1031) is a U.S. Department of Agriculture, Cooperative State Research, Education, and Extension Service (USDA-CSREES) regional project focused on developing and evaluating the suitability of new varieties and advanced clones from multiple breeding programs for a range of environments. This multistate project and its predecessors have been in existence for more than two decades, and they have resulted in the collection of a significant amount of standardized potato trial data. We have developed an interactive potato variety database that allows researchers and end-users to access and obtain potato variety trial results in one centralized site. The database is populated with the results of potato variety trials conducted in eight states (Florida, Maine, New Jersey, New York, North Carolina, Ohio, Pennsylvania, and Virginia) and two Canadian provinces (Prince Edward Island and Quebec). It currently contains over 35 data features and was developed primarily for scientists interested in potato variety development, growers, and allied industry members. Hypertext mark-up language (HTML) and hypertext preprocessor (PHP) were used to develop the database interface.

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