2004 SAKHANOKHO Induction of Somatic Embryogenesis.pdfVIP

R ep ro du ce d fr om C ro p S ci en ce . P ub lis he d by C ro p S ci en ce S oc ie ty o f A m er ic a. A ll co py rig ht s re se rv ed . GENOMICS, MOLECULAR GENETICS BIOTECHNOLOGY Induction of Somatic Embryogenesis and Plant Regeneration in Select Georgia and Pee Dee Cotton Lines Hamidou F. Sakhanokho, Peggy Ozias-Akins, O. Lloyd May, and Peng W. Chee* ABSTRACT methods suffer from extremely low transformation effi- ciencies. Essentially all commercial cultivars in the mar-The current standard strategy for cotton transformation uses Agro- ket were developed by first transforming the transgenebacterium for gene transfer and regeneration via somatic embryogene- sis, but it is successful only for a handful of cultivars. This study was into a highly regenerable Coker line, typically from Coker undertaken with the prospect of expanding the number of elite Upland 312, and then introducing the transgene into the elite cotton (Gossypium hirsutum L.) genotypes that can be regenerated cultivars by backcross breeding (Trolinder, 1995). The via somatic embryogenesis. We tested 15 elite Upland cotton lines availability of additional cultivars or elite lines that can from Southeast germplasm: eight lines developed by the Georgia Agri- be directly transformed would greatly benefit the devel- culture Experiment Station and seven by the USDA-ARS Pee Dee opment of transgenic cotton cultivars. Increasing the cotton breeding program. These genotypes were tested on three em- number of regenerable genotypes could also benefitbryo initiation–maturation media that were previously found to be cotton genomic research by augmenting the use of genecapable of inducing somatic embryogenesis in diverse cotton species. complementation, gene knock-out, or other similar ap-Three Pee Dee lines, PD 97019, PD 97021, and PD 97100, and one proaches in gene discovery and gene confirmation whereGeorgia line, GA 98033, responded to at least one of the three medium treatments. As expected, the r