Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: June 1, 1998
Publication Date: N/A
Interpretive Summary: Genetically engineered herbicide resistant kenaf varieties would greatly enhance kenaf establishment, crop development, stalk yields, and harvest quality. Herbicide resistant genes are now available and have been successfully incorporated in crops such as cotton. The first requirement of incorporating a gene into kenaf is the development of a cell culture system specifically designed for kenaf. The objective of this research was to develop a cell culture system for kenaf which is rapid, genotype independent, and results in rooted plants at a high frequency. A gene vector was used in the transformation of kenaf. Seeds from kenaf varieties Everglades 71, Tainung #1, and Tainung #2 were used in the transformation process. Contamination was controlled and was minimal for all three cultivars. Kenaf shoot apices were co-cultivated with different Agrobacterium tumefaciens strains (LBA4404, EHA101S, and Z707S) containing genes for resistance to phosphinotrician (ppt) and hygromycin (hyg). The highest percentages of rooted plants on selective medium were obtained from shoots co-cultivated with Agrobacterium strain LBA4404. The Agrobacterium strain LBA4404 produced slightly more established plants with Tainung #2 than Tainung #1, while Everglades 71 was a distance third for percent of plants established in soil. Initial results from this research provide a reliable cell culture system that produces rooted kenaf plants that can be readily established in soil.
A practical genetic transformation method for kenaf requires that the system is rapid genotype independent, and results in high frequency of transformants. A system is described which uses an easily regenerated explant, the 3-to-4-day-old shoot apex, and Agrobacterium tumefaciens as the gene vector. Shoot apices were isolated, surface sterilized, and germinated on a Murashige and Skoog (MS) salts medium. Shoot apices were co-cultivated with different Agrobacterium tumefaciens strains, LBA4404, EHA101S and Z707S, containing genes for resistance to phosphinotricin (ppt) and hygromycin (hyg). After co-cultivation for 3 days in the light, shoot apices were transferred to the selective medium containing 10 mg/l ppt or 16 mg/l hyg formed roots on MS medium. The highest percentages of rooted plants on selective medium were obtained from shoots that were co- cultivated with Agrobacterium strain LBA4404.