|Castillion, Javier - FORMER USDA EMPLOYEE|
|Smith, Francine - SANFORD SCIENTIFIC|
Submitted to: Plant Cell Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 1, 2003
Publication Date: April 3, 2004
Citation: Kamo, K., Jones, B., Castillon, J., Smith, F. 2004. Dispersal and Filtration of Embryogenic Callus Increases the Frequency of Embryo Maturation and Conversion for Hybrid Tea Roses. Plant Cell Reports, 22:787-792. Interpretive Summary: Genetic engineering of roses offers the opportunity to incorporate genes of interest into roses. There are numerous cultivars of roses, and genetic engineering of roses has been applied to only a few cultivars because of the difficulty in regenerating rose plants from many cultivars. The technique of dispersing undifferentiated callus cells and then filtering the dispersed cells to isolate globular-stage embryos is described in this manuscript. Culturing cells from these treatments results in an increased efficiency of embryo development and their further development to plants. The method has been applied to two commercially important cultivars of hybrid tea roses.
Technical Abstract: The number of plants regenerated from embryogenic cells of two of three Rosa hybrida cultivars studied, Kardinal and Classy was increased by shaking embryogenic callus in liquid medium for three hours to disperse the callus followed by filtration through a 530 um screen to isolate globular-stage embryos and cell clusters. Dispersed callus of three cultivars, Kardinal, Classy, and Tineke, produced 61-135 cotyledonary-stage embryos/100 mg fresh weight callus as compared to intact callus that had not been dispersed and produced 0-3 cotyledonary-stage embryos/100 mg fresh weight callus when the callus was cultured on solidified Murashige and Skoog¿s basal salts medium supplemented with 0.25% activated charcoal. A maximum of 610 cotyledonary-stage embryos/100 mg fresh weight callus developed from cell clusters and globular-stage embryos that were <530 um in diameter after they were cultured on solidified Murashige and Skoog's basal salts medium for two months. Cotyledonary-stage embryos isolated from both dispersed callus and callus that had passed through various screen sizes showed a significantly higher conversion frequency to plants than cotyledonary-stage embryos isolated from intact callus of the cultivar Classy.