Screening of muscadine grape (Vitis rotundifolia) plants in vineyards has revealed that many plants carry Xylella fastidiosa; under suitable conditions, this bacterium causes Pierce's disease which can result in considerable loss. To determine whether propagation of muscadine through shoot tips would eliminate X. fastidiosa, plants were injected with this bacterium. After demonstrating infection, shoot tips were collected and cultured. according to the technique of Barlass and Skene (1978). Plants which were regenerated were found to be free of the bacterium. To determine whether this shoot-tip culture technique would be effective for propagation of a diverse group of muscadines, 19 cultivars were tested. Three of the cultivars failed to produce any plants, and several others reproduced at a low rate of efficiency. In an attempt to improve the rate of regeneration, several modifications to the technique were tested. For most cultivars, better initiation occurred on liquid medium, more shoots were produced with BA than with 2iP, and the addition of adenine sulfate and sodium phosphate improved the regeneration frequency.
Carol D. Robacker and C.J. Chang
James M. Spiers and John H. Braswell
The effects of varying N, Ca, and Mg fertilization levels on plant growth and leaf elemental content of `Sterling' muscadine grapes (Vitis rotundifolia Michaux) were studied in a 2 year sand culture experiment. Increased N levels reduced leaf K, Ca, and Mn and increased leaf N and P concentrations plus plant growth. Calcium fertilization increased leaf Ca, decreased leaf Mg, but did not affect plant growth. Mg fertilization reduced leaf K and Ca and increased leaf Mg plus plant growth. Visual symptoms, assumed to be Mg deficiencies, were decreased by Mg fertilization and highly correlated to leaf Mg content. Plants which received the highest Ca fertilizer level had fewer deficiency symptoms when treated with the highest rate of N. Calcium fertilization tended to slow both Mg uptake and deficiency symptoms reductions caused by increases in levels of applied Mg. Growth of `Sterling' muscadine plants was positively correlated to leaf N and Mg and negatively related to leaf K, Ca, Mn, Zn, and Cu concentrations.
Sebastain N. Awondo, Esendugue Greg Fonsah, and Dennis J. Gray
Muscadine grape is a species native to the southeastern United States and is well adapted to the warm and humid conditions in this region. Unlike widely consumed “bunch” grapes (primarily Vitis vinifera ), muscadine grapes form smaller clusters
Creiehton L. Gunton and James M. Spiers
The role of phosphorus (P) in magnesium (Mg) translocation from roots to leaves of muscadines (Vitis rotundifolia Michx.) was investigated in shadehouse experiments. Vines of 13 clones were grown for two seasons in sand culture fertilized with nutrient solutions containing no P (-P), 20 PPM P (+P), and -P plus P added during the two weeks before harvest (-P+P). Leaves were sampled at the end of each growing season and in July of the second year and analyzed for P, potassium (K), and Mg content. Mg and K contents of roots were determined at the end of the second year. No interactions occurred between clones and P fertilization levels for Mg or K content, indicating no differences among clones in response of these minerals to P treatments. Leaf Mg content was slightly but significantly lower for -P than +P treatments in the `92 and July `93 samples but about rhe same in September `93. Root Mg content in September `93 was higher for +P than -P or -P+P. No evidence was found that Mg translocation from root to leaves was mediated by P. No Mg deficiency symptoms were visible on the leaves for any treatment.
Stephen J. Stringer, Donna A. Marshall, Blair J. Sampson, and James M. Spiers
pierce's disease in Vitis J. Amer. Soc. Hort. Sci. 102 695 697 Olein, W.C. 1990 The muscadine grape: Botany, viticulture, history, and current industry HortScience 25 732 739 Sampson, B.J. Noffsinger, S. Gupton, C. Magee, J. 2001 Pollination biology of
Teresa L. Walker, Justin R. Morris, Renee T. Threlfall, Gary L. Main, Olusola Lamikanra, and Stephen Leong
Muscadine grapes (Vitis rotundifolia Michx.), native to the southeastern United States, have a distinct flavor, and grocers are interested in marketing them as table grapes. Two studies using 'Fry' muscadines were conducted to assist the muscadine industry in providing quality table grapes. Study 1 (1998 and 1999) evaluated density sorting and relationships between maturity, color, soluble solids, firmness, shelf life, and sensory evaluation of grapes. Study 2 (1998) determined the effect of storage on quality attributes of different maturities of grapes and evaluated use of polyethylene bags to extend their storage. Density separation successfully sorted grapes by maturity. Muscadine berry color may allow for visual or electronic sorting to eliminate immature fruit. Sensory panelists could distinguish differences in maturities for all sensory attributes. In 1999 maturities 3 and 4 (≈24-33 soluble solids: acid ratio) were preferred overall by panelists. As maturity increased, soluble solids and pH increased, and acidity decreased. Firmness decreased as maturity and storage at 2 °C increased. Percent decay increased with maturity and storage time. Grapes stored in polyethylene bags had reduced decay. A chart developed from the 1999 data related berry color to soluble solids: acid ratio, soluble solids, tartaric acid, and pH. Data from these studies can be used by industry to establish harvest parameters and enhance marketability of 'Fry' muscadine grapes.
R.K. Striegler, J.R. Morris, P.M. Carter, J.R. Clark, R.T. Threlfall, and L.R. Howard
A muscadine grape (Vitis rotundifolia) planting was established in 1996 at the Southwest Research and Extension Center in Hope, Ark., to provide information on the performance of muscadine grape cultivars in a region where cold hardiness is not a major limitation. This research evaluated harvest parameters, fruit and juice quality, and nutraceutical potential of selected muscadine cultivars grown in southwestern Arkansas. The cultivars evaluated were `Black Beauty', `Carlos', `Cowart', `Doreen', `Early Fry', `Fry', `Granny Val', `Ison', `Jumbo', `Late Fry', NC67A015-17, NC67A015-26, `Nesbitt', `Scarlett', `Southern Home', `Sterling', `Sugargate', `Summit', `Supreme', and `Tara'. Muscadine cultivars differed in productivity and fruit quality. In 2002 and 2003, juice was produced from `Carlos', `Granny Val', `Ison', `Nesbitt', `Southern Home', `Summit', and `Supreme' grapes. `Black Beauty' was also produced into juice in 2003. In 2002, `Nesbitt' grapes had the highest juice yield, 520 L·t–1 (124.6 gal/ton). `Ison' and `Supreme' juice had the highest soluble solids level. In 2003, `Granny Val' grapes had the highest juice yield, 551 L·t –1 (132.0 gal/ton). `Southern Home' juice had the highest soluble solids. The press materials of muscadine grapes were a potential source of high levels of nutraceutical compounds. Dried seeds had the highest total phenolic and oxygen radical absorbance capacity (ORAC) levels followed by the dried skins, the grapes, and then the juice. The skins of the black cultivars had the highest total anthocyanins level. `Supreme' seeds had the highest total phenolic and ORAC levels while `Ison' skins had the highest total anthocyanin levels. Based on yield, harvest, and juice quality, cultivars recommended to growers in southwestern Arkansas and other areas with a similar climate include `Black Beauty', `Carlos', `Fry', `Granny Val', `Nesbitt', `Southern Home', `Summit', and `Supreme'.
Jean Carlos Bettoni, Aike Anneliese Kretzschmar, Remi Bonnart, Ashley Shepherd, and Gayle M. Volk
cultivars assigned to Vitis vinifera ( Li et al., 2017 ). Wild Vitis species as well as Muscadinia rotundifolia have been used for hybrid grape breeding as new cultivars and rootstocks, many of which provide resistance to pests and diseases ( Carimi et
Sadanand A. Dhekney, Zhijian T. Li, Michael E. Compton, and Dennis J. Gray
muscadine grape cultivars ( Vitis rotundifolia ) Plant Cell Tissue Organ Cult. 27 7 14 Gray, D.J. Jayasankar, S. Li, Z. 2005 Vitis spp. grape 672 706 Litz R.E. Biotechnology of fruit and
dans l'espéce Vitis vinifera L. d'un caractere de résistance á oidium ( Uncinula necator Schw. Burr.) issu de l'espéce Muscadinia rotundifolia (Michl.) Small Vignevini 12 141 146 Galet, P. 1988 Cépages et vignobles de France, Tome 1. Les vignes