Project Number: 500-42-001-62
Project Type: Grant

Start Date: Mar 24, 2004
End Date: Mar 23, 2005

Objective:
1. Test transgenic Dakota Pearl minitubers for the presence of the construct and the presence of A-II proteins of UGPase; 2. Develop microtuber explants of the cultivar Norchip and numbered selection MSF099-3 (provided by potato breeder David Douches, Michigan State University) for transformation with the anti-sweetening gene; 3. Utilize minitubers for field production of transgenic potatoes to be evaluated for (1) sugars, (2) processing color, and acrylamide content following processing from cold temperature storage (4 C) compared to wild-type mother tubers; 4. Continue to propagate superior transgenic lines.

Approach:
Objective 1: One hundred and eighty plants representing thirty-four independent lines of transgenic Dakota Pearl have been grown in the greenhouse facilities at the University of MN, Crookston. Plantlets were grown in a growth chamber for one week (12 h day; 22 C, 3000 lux light intensity) and then transferred to a greenhouse for two additional weeks. In September, 2003, plantlets were transferred to 6" pots for minituber production. After 3 months minitubers will be harvested and tested for the presence of the construct and A-II isozymes of UGPase. Minitubers of each line will be planted in the spring, 2003, along with wild-type plants for the production of mature field growth potatoes. Objective 2: Microtubers of Norchip and MSF099-3 will be prepared for Agrobacterium t. transformation with the pGUT construct containing the Asgene 'UgpA' using the same procedure used with Dakota Pearl (as described by Dr. Bill Belknap, personal communication). After the development of rooted plantlets, the number of integrated copies will be tested by Southern blot analysis. Only those plants carrying a single copy of the integrated construct will be continued. Objective 3: Minitubers of transgenic Norchip and MSF099-3 lines will be developed as described above for Dakota Pearl in Objective 1. Following production of mature field growth potatoes they will be harvested, suberized at room temperature for two weeks and then placed into cold storage (4 C) for three months. The transgenic and wild-type tubers will be analyzed for (1) UGPase isozyme profiles using activity-stained native-gels (Gupta and Sowokinos 2003), (2) sucrose and glucose concentrations using the YSI-2700 select sugar analyzer (Sowokinos and Preston 1988) and (3) final-product chip color and chip color reflectance (Lulai and Orr 1980). Acrylamide content will also be evaluated using a gas chromatography/mass spectrometry (GC/MS) procedure as described by Tareke et al. (2002). Objective 4: Seed increase of superior transgenic lines will be initiated to provide material for large scale evaluation of yield, phenotypic characteristics, and storage performance.

Project Team

Bennett, A. Rick Joseph Sowokinos - Professor 301-504-6915

Related National Programs

Plant Diseases (303)