Over one hundred Gladiolus plants of the commercially important cultivars `Jenny Lee' and `Peter Pears' have been stably transformed following particle bombardment on regenerable callus, suspension cells, or cormel slices. The phosphinothricin acetyltransferase gene which confers phosphinothricin resistance was cotransformed with either antiviral genes or the uidA reporter gene coding for β- glucuronidase expression. Transformed plants were regenerated following selection on concentrations of phosphinothricin which varied with the type of tissue used for bombardment. Integration of foreign DNA was confirmed by polymerase chain reaction and gene expression.
Kathryn Kamo, Alan Blowers, Franzine Smith, and Joyce Van Eck
Mack Thetford, Debbie Miller, Kathryn Smith, and Mica Schneider
Survival and subsequent growth of two beach species produced in containers of differing volume and depth were evaluated following transplant on Eglin Air Force Base, Santa Rosa Island, Fla. Rooted cuttings of gulf bluestem (Schizachyrium maritimum) were produced in four container types: 1-gal (gallon), 0.75-gal treepot, 1-qt (quart), or 164-mL Ray leach tube (RLT) containers. Root and shoot biomass of gulf bluestem harvested after 12 weeks in container production were greatest for plants grown in treepot containers and root: shoot ratio decreased as container size increased. Regardless of container size, survival of beach-planted gulf bluestem was 100%. Basal area of plants from standard gallon and treepot containers was similar 11 months after transplant and basal area for plants from treepot containers remained greater than plants from quart or RLT containers. Effect of planting zone [92, 124, 170, and 200 m landward of the Gulf of Mexico (Gulf)] on transplant survival was also evaluated for inkberry (Ilex glabra). Seedling liners of inkberry were produced in 3-gal treepot or gallon containers. Inkberry was taller when grown in 3-gal treepot containers than when grown in gallon containers. Regardless of container size, all inkberry planted 92 m from the Gulf died. Inkberry survival (>75%) when grown in 3-gal treepot containers was two to six times greater than plants grown in gallon containers (15%, 50%, 40%; 124, 170, and 200 m from Gulf, respectively). After 15 months, inkberry grown in 3-gal treepot containers remained larger with 1.5 times the mean maximum height and twice the mean canopy area compared to those grown in gallon containers.
Carol A. Miles, Kathryn Kolker, Tracy Smith, Jenn Reed, Gail Becker, and Carolyn Adams
Icebox watermelons first appeared in the United States about 50 years ago. They weigh between 6 and 12 pounds and come in a variety of shapes and colors. With a rising interest in local production, organic produce, and direct marketing, farmers in Washington are looking to diversify crop varieties to meet these demands. Icebox watermelons offer a means of locally producing high-quality watermelons. In 2004 and 2005, we evaluated icebox watermelon varieties to determine which are most suitable for production in our region. In 2004, we evaluated 44 varieties of icebox watermelon and in 2005 we evaluated 100 varieties at WSU Vancouver REU. Varieties were seeded in the greenhouse mid-April and transplanted to the field by mid-June. The greenhouse and field were managed organically. The study design was a randomized complete-block with three replications. Plots were single rows, 6.1 m long, with seven plants per plot. Spacing was 1 m between plants and 3 m between rows. Plants were mulched with black plastic and drip-irrigated 2.5 cm per week. Melons were harvested twice weekly, from mid-August through mid-October. Fruit weight, number, and size were measured, and percentage of soluble solids was measured using a °Brix meter. General eating quality was also evaluated. Summaries of selected varieties will be presented here. To view other varieties included in the trial, see our website, http://agsyst.wsu.edu. Results of this study show significant differences among icebox watermelon varieties in total yield, number of fruit per plot, average fruit weight, number of days to harvest, and percentage of soluble solids. These preliminary findings indicate that more than 80 varieties of icebox watermelon can be grown productively in our region.
Kathryn Kamo, Alan Blowers, Franzine Smith, Joyce Van Eck, and Roger Lawson
More than 100 transgenic Gladiolus plants were recovered after particle bombardment of regenerable suspension cells and callus. For transformation, Gladiolus callus and suspension cells were co-bombarded with phosphinothricin acetyltransferase-(PAT) and ß- glucuronidase (GUS) -expressing plasmids. Stably transformed calli were selected on medium containing either phosphinothricin (PPT) or bialaphos followed by transfer to a regeneration medium to recover transgenic plants. Stable transformation was confirmed by detection of the PAT gene by DNA gel blot analysis and by enzymatic assays to measure GUS activity. In general, particle bombardment of regenerable suspension cells rather than callus resulted in the largest number of transformants. The rate of co-expression for GUS in PPT-resistant plants was high (≈ 70%). Promoters that are typically more efficient in dicotyledonous plants were very active in Gladiolus, a monocotyledonous bulb plant. Establishment of an efficient transformation protocol for Gladiolus will now allow the introduction of transgenes to confer resistance to the viral and fungal pathogens that decrease Gladiolus production.