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ARS Home » Research » Publications at this Location » Publication #92003
Title: FACTORS INFLUENCING GENE TRANSFER EFFICIENCY DURING THE EARLY STAGES OF TRANSFORMATION OF HIGHBUSH BLUEBERRIES

Author
item CAO, XIAOLING - CONTRACT EMPLOYEE
item LIU, QUINGZHONG - CONTRACT EMPLOYEE
item Rowland, Lisa
item Hammerschlag, Freddi

Submitted to: Blueberry Research Extension North American Workers Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/27/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Plant transformation provides an important adjunct to sexual hybridization, because it allows us to introduce genes into plants that are outside the scope of conventional plant breeding. Numerous genes have been isolated and these genes will be used increasingly for the introduction of important traits into crops. Blueberry (Vaccinium spp.) is an especially suitable target for improvement through direct gene manipulations because of the genetic limitations associated with high heterozygosity and polyploidy that hamper improvement through traditional breeding methods. Improvement of blueberry via genetic engineering will depend on an efficient gene delivery system, a system for selection, and reliable, high frequency shoot regeneration. To date, there is only one report of blueberry transformation, but this has not yet been confirmed by Southern analyses. In the present study, we report on several factors that influence the efficiency of Agrobacterium-mediated gene transfer into leaf cells of several commercially important blueberry cultivars. This information should be useful to other scientists interested in improving blueberry via gene transfer technologies.

Technical Abstract: Several factors were investigated for their influence on the transfer of an intron - containing B-glucuronidase (GUS) gene into highbush blueberry (Vaccinium spp.) leaf explants during the early stages of Agrobacterium-mediated gene transfer including days of cocultivation, strain of Agrobacterium tumefaciens, explant age and genotype. The number of GUS expressing leaf zones and calli were counted immediately and two weeks after cocultivation, respectively, to evaluate the gene transfer process. Agrobacterium tumefaciens strain EHA105 (pEHA105/p35SGUSint) was more effective for transformation than strain LBA4404 (pAL4404/p35SGUSint). Four days of cocultivation with A. tumefaciens strain EHA105 yielded about 50-fold as many GUS expressing zones compared to two days cocultivation. Differences among cultivars were observed for both GUS expressing leaf zones and calli. For some cultivars, explant age influenced number of GUS expressing leaf zones and calli. In most cases, the number of GUS expressing calli was highest in those cultivars where GUS expression in leaves was high.