Establishing a Source of Disease Free, True-to- Type Muscadine Vines Zvezdana Pesic Van Esbroeck, Bill Cline, Benny Bloodworth, Rose Caldwell, Christie Almeyda Plant Pathology, NCSU
Purpose: The purpose of this project is to use micropropagation and virus testing to establish a source of clean, disease-free, true-to-type muscadine grape vines.
What are the Goals? Trueness-to-type Eliminating plant-borne diseases Establishment of a tissue culture plant source
Muscadine grape vines are often not true-to-type (wrong cultivar, mixed cultivars) TRUENESS-TO-TYPE
Trueness-to-type is very important -- especially when marketers specify what cultivars they will buy CARLOS NOT CARLOS
Muscadine nursery stock can harbor pathogens (viruses, bacteria, fungi) that are carried by plants to new vineyards. ELIMINATING PLANT-BORNE DISEASES
Pierce s Disease (PD) Bacteria (Xylella fastidiosa) Muscadines are fairly resistant to PD Causes marginal leaf burn on Carlos
Crown Gall Bacteria (Agrobacterium tumefaciens) Muscadines are commonly infected Fleshy, irregularlyshaped gall Associated with cold injury (note aerial roots above point of injury)
Fruit Rots Macrophoma rot Botryosphaeria spp. Bitter Rot Greeneria uvicola Ripe rot Colletotrichum spp. Sooty mold Peltaster fructicola
Some examples of plant-borne diseases in BLUEBERRY Blueberry Red Ringspot (virus) Blueberry Bacterial Scorch Blueberry stem canker (fungus) Bluebery stem blight (fungus)
Blueberry Red Ringspot Virus Mapping at NCSU Ideal Tract in a new field spread very slow over three years of observation (<1% per year) Most often spread by propagation Start with clean plants and do not propagate from infected plants Fungicides do NOT control this disease
Bacterial leaf scorch (Xylella) Similar to Pierce s Disease of grape Not seen or confirmed in NC Positive ID in GA, FL Most severe on GA cultivar V-1, also Star Sharpshooter insects are the most likely vector Spread by propagation? Spread by summer mowing/hedging?
Bacterial leaf scorch (Xylella) in GA
Bacterial scorch Oak Leaf pattern
Bacterial scorch in Georgia
Muscadines are one of the few vegetatively propagated small fruit crops for which no clean plant source exists. ESTABLISHMENT OF A TISSUE CULTURE PLANT SOURCE
NCSU Breeding Program greenhouse pollination study
NCSU Breeding Program Seedlings Crosses
NC 1005
Softwood propagation of freshmarket cultivars
Tissue Culture for Muscadines? Ease of propagation New cultivars Old cultivars Exclude diseases Crown Gall Pierce s Disease Plant-borne fungi Viruses?
CARLOS (NCSU, 1970) Self-fertile Highly productive Dry stem scar Best cultivar for wine +90% of NC acreage Tart skin Not highly rated for fresh market (does not chill well, small size)
NOBLE (NCSU, 1974) Very productive Self-fertile Stable pigments Small size Wet stem scar #1 muscadine used for wine in Florida Not for fresh sales!
SUMMIT Pink-bronze, very productive and vigorous, edible skin, few rots
TRIUMPH early-ripening, dry scar, productive, with edible skin, few rots
NESBITT Medium large, perfect-flowered, good vigor, productive, dry stem scar
Project Activity Who Timeline Identify clonal sources and verify trueness-to-type by examining fruit at harvest. Mark vines with permanent tags, map and GPS Collect emerging shoots for tissue culture Test for viruses and other pathogens Micropropagation Transfer plantlets to pots in the greenhouse Cline, Bloodworth, Pesic- VanEsbroeck Caldwell, Cline, Pesic- VanEsbroeck Almeyda, Cline, Pesic- VanEsbroeck Caldwell, Pesic- VanEsbroeck Caldwell, Pesic- VanEsbroeck Fall 2014 Spring 2015 Spring 2015 through 2016 Spring 2015 through 2016 Fall 2015 through 2016
Facilities at the Micropropagation and Repository Unit (MPRU) in Raleigh The MPRU has all necessary infrastructure (labs, greenhouses, growth chambers) in place for the project, and experienced personnel are on staff to perform the work. Facilities valued in excess of $250,000 include: Micropropagation: --Biological safety cabinets (laminar flow hoods) for meristem micropropagation --Percival tissue culture chambers (7 units) for controlled maintenance environments --Conviron environmental chambers for heat treating and establishing rooted plants -- Stereoscope, autoclave, microsurgical tools, ph meter, hot plates, balances -- Greenhouses with screen cages to isolate plants undergoing virus testing -- Clean greenhouse for tested material -- Screen house for winter chilling -- Isolation greenhouse for diseased plants Virology Lab: --Thermocyclers (DNA amplifiers) --ELISA reader (enzyme linked immunosorbent assay) --Real-time PCR (polymerase chain reaction) --Real-time gel imager --Other associated lab equipment
Facilities at the NCSU Horticultural Crops Research Station in Castle Hayne The station includes two sites, a 50-acre blueberry research farm and a 60-acre main farm. The main farm includes offices, laboratories, greenhouses, and seven (7) acres of muscadine research vineyards. For this project, we will utilize: The Plant pathology lab, equipped to isolate and identify pathogens. The muscadine cultivar vineyard with clearly marked vines of known cultivars.