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Greeneria uvicola causes bitter rot on Vitis vinifera (bunch grapes) and Muscadinia rotundifolia (muscadine grapes) in warm moist temperate and subtropical regions. This study investigated the phylogenetic relationship of G. uvicola representatives from Australia (67 isolates), the USA (31 isolates), India (1 isolate) and Costa Rica (1 isolate) and compared their pathogenicity and fungicide sensitivity. Differences in cultural and conidial morphology were observed between the isolates from Australia and the USA. Phylogenetic relationships were determined based on three gene regions: the ribosomal DNA ( rDNA) internal transcribed spacer 1 (ITS1-5∙8S-ITS2), 28S large subunit (LSU) nuclear rDNA and β-tubulin-2. Greeneria uvicola isolates were clearly differentiated into four groups: isolates from Australia and India; USA isolates from V. vinifera; USA isolates from M. rotundifolia; and the isolate from Costa Rica. All isolates were pathogenic on V. vinifera (cv. Chardonnay) berries although those originating from M. rotundifolia were not as aggressive as isolates from V. vinifera, irrespective of geographical origin. Sensitivity to pyraclostrobin and salicylhydroxamic acid (SHAM) was studied. Despite differences in fungicide applications, hyphal growth inhibition was not significantly different for geographical location, cultivar, tissue, year of collection or different spray regimes. For the Australian and USA isolates, fungal growth inhibition was significantly greater for pyraclostrobin than for SHAM, and was significantly greater for the combined treatment than for each of the fungicides applied singly. The aetiological and epidemiological knowledge of bitter rot collected through this study will aid better prediction and management strategies of this pathogen. [ABSTRACT FROM AUTHOR]

Muscadine grapes (Vitis rotundifolia Michx) are considered as excellent genetic resources for grape breeding programs as they are known for their hardiness and resistance to pests and diseases. However, contrary to popular belief, our study indicated that not all muscadine cultivars are resistant to anthracnose disease. In order to identify a source of genetic tolerance towards anthracnose among muscadine cultivars, a series of in-situ and ex-situ experiments were conducted through strict and sensitive screening processes. Two consecutive years of field evaluation of 54 grape cultivars showed various levels of anthracnose incidence among the cultivars between a scale of 0 (tolerant) to 5 (highly-susceptible). Resistance bioassay by inoculation of different spore densities of Elsinoë ampelina on 40 cultivars presented similar results and was consistent with those obtained from the field test. A real-time PCR analysis was conducted to investigate differences of gene expression between susceptible and tolerant cultivars and to confirm results by phenotypic identification. Expression of genes encoding chalcone synthase, stilbene synthase, polygalacturonase-inhibiting protein, chitinase and lipid transfer-protein was only detected in tolerant cultivars. Resistant muscadine cultivars identified in this study could be excellent candidates for grape disease resistance breeding programs. [ABSTRACT FROM AUTHOR]

Abstract: Muscadine grapes are important fruits grown in the southeastern United States. They are a good source of anthocyanins, but confirmatory analyses of the structure of individual anthocyanins in muscadine grapes using more advanced instrument are lacking. In this study, the anthocyanins of muscadine grapes were analyzed using HPLC-MS with electrospray ionization. Approximately 90% of the total anthocyanins were 3,5-diglucoside of delphinidin, cyanidin and petunidin; the remaining 10% were 3,5-diglucoside of peonidin and malvidin. There was a significant difference of total anthocyanin content among different cultivars of muscadine grapes with purple-skinned muscadine grapes having significantly higher levels of anthocyanins than bronze-skinned muscadine grapes. The total anthocyanin content in purple-skinned Jumbo and Cowart muscadine was 4.1 and 2.6mg/g dry weight, respectively, while the total anthocyanin content in bronze-skinned Higgin and Carlos was negligible. The anthocyanins were mainly concentrated in the skin of the grapes. The results of the present study confirmed some of the anthocyanins reported by previous studies and also found one anthocyanin that might be falsely identified by previous studies. [Copyright &y& Elsevier]

The article presents information on Hall, an early-season self-fertile bronze muscadine grape from the University of Georgia College of Agriculture and Environmental Sciences. It provides a background on the origin of the cultivar, which resulted from a cross of Fry by Tara made by horticulturist Melvin Hall in 2001. Information is also presented on the cultivar's features, performance, and availability.

The article provides information on Eudora muscadine grape. This fruit is for fresh market production and has been accepted for joint release as a public domain cultivar by the University of Florida Experiment Station and the U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS). An overview of the fruit's origin is presented, along with a brief description of the fruit's features and performance. Also discussed is the fruit's availability.

The article provides information on Southern Jewel, a new muscadine grape cultivar to be released by the University of Florida in Gainesville. Southern Jewel, which is said to be disease-resistant, is well-suited for fresh fruit consumption because of its taste and the texture of its skin. The leaves of Southern Jewel grow up to an average of 8 centimeters (cm) in length and 7 cm in width. It notes that the fruit of Southern Jewel ripens early despite its smaller size.

The article provides information on the Delicious muscadine grape cultivar being released by the University of Florida. It describes the variety as ideal for fresh fruit consumption due to its excellent taste and texture with an edible skin. The semirecumbant growth habit of the cultivar is three- to six-centimeters (cm) internodes. Also noted is the suitability of Delicious to deep sandy soils.