|Gilbert, Robert - UNIVERSITY OF FLORIDA|
Submitted to: International Society of Sugar Cane Technologists Proceedings
Publication Type: Proceedings
Publication Acceptance Date: December 1, 2004
Publication Date: January 6, 2005
Citation: Miller, J.D., Tai, P.Y., Edme, S.J., Comstock, J.C., Glaz, B.S., Gilbert, R.A. Basic germplasm utilization in the sugarcane development program at Canal Point, FL, USA. International Society of Sugar Cane Technologists Proceedings. Vol. 2:532-536. 2005. Interpretive Summary: Sugarcane scientists need new genetic sources to increase yields and particularly to provide resistance to pests and environmental stresses. Sugarcane cultivars have a low level of genetic diversity resulting from a narrow genetic base. It was hypothesized that wild canes could be exploited in the Canal Point crossing program for introduction of genes of resistance to diseases and genes to increase yields into cultivated varieties. Crosses were made between commercial cultivars and wild relatives of sugarcane (S. officinarum, S. spontaneum, S. robustum, Erianthus, and Miscanthus) and the progeny were evaluated for yields. It was found that the first generation of introgression (I1), derived from crosses that involve S. offininarum and robustum, could be used directly for selection in the regular breeding program. However, several generations of introgression breeding were necessary to bring the progeny from crosses involving the other wild relatives to commercial standards. Saccharum species must be included in the introgression program to increase sugar yield, since its progeny had higher sucrose content that those derived from Erianthus and Miscanthus. As a success story, CP 96-1252 is one cultivar with a widened germplasm base that was recently released to the Florida industry. CP 96-1252 is an I1 progeny derived from a polycross involving NG 57-252, an S. officinarum clone, as the female parent. Florida sugarcane growers are the direct beneficiaries of this introgression breeding carried out by the cooperative USDA-ARS sugarcane breeding program in Florida. The sugarcane scientific community can use these results as a guide to maintain genetic diversity in their respective programs, to increase yields, and to improve disease resistance in commercial cultivars.
Technical Abstract: Sugarcane (Saccharum spp.) growers in Florida need profitable cultivars that sustain productivity through at least two ratoon crops in the presence of biotic and abiotic stresses. The Canal Point (CP) breeding program utilizes the World Sugarcane Germplasm Collection as a source of germplasm to broaden the genetic base of the CP breeding populations, and as one strategy to develop cultivars that meet the needs of Florida growers. Crosses were made between CP cultivars and wild relatives of sugarcane (S. officinarum, S. spontaneum, S. robustum, Erianthus, and Miscanthus) and the F1 or introgression (I) progeny evaluated for cane and sugar yields in the regular stages of the breeding program. I1 progeny, derived from crosses between CP cultivars and S. officinarum or robustum, were used directly for performance evaluation, whereas F1 clones derived from crosses with S. spontaneum, S. robustum, Erianthus spp., and Miscanthus spp. went through additional introgression crosses and selection before performance evaluation was carried out. Mean progeny performance in sucrose content of clones derived from Miscanthus and Erianthus was lower than that from Saccharum. Gradual increases in sucrose yield were observed with subsequent introgression generations involving S. spontaneum clones (US 56-15-8 and SES 196), S. robustum clones (NG 77-132 and NG 77-147), and Miscanthus clones (IS 76-178, IK 76-99, and US 47-11). So far, CP 96-1252 was the only cultivar with a widened germplasm base that was recently released to the Florida industry. CP 96-1252 is an I1 progeny derived from a polycross involving NG 57-252, an S. officinarum clone, as the female parent.