|Richard Jr, Edward|
Submitted to: International Society of Sugar Cane Technologists Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 1/20/2003
Publication Date: 5/20/2003
Citation: Pan, Y., Tew, T.L., Grisham, M.P., Richard Jr, E.P., White, W.H., Veremis, J.C. 2003. Selection of de novo saccharum hybrids with saccharum spontaneum cytoplasm using microsatellite DNA markers. 7th International Society of Breeding and Germplasm Workshop Abstract Book, May 5-9, 2003, Durban, South Africa. p. 17-18.
Technical Abstract: In an effort to explore the potential impact of S. spontaneum cytoplasm in modern sugarcane varieties, mature flowers of ten S. spontaneum clones were pre-treated with hot water (500C, 5 minutes) before crossing with flowers of six elite sugarcane varieties in bi-parental settings in 2001. S. spontaneum clones were IMP9834, MOL1032, SES84-58, SES205A, SES234A, SES323, US00-19, US00-20, US00-21, and US00-26. The four US clones were progeny of (Mandalay x SES231), both S. spontaneum. Elite sugarcane varieties were CP89-831, H96-291, HoCP01-553, HoCP96-540, HoCP99-839, and LCP85-384. Self-pollination of maternal S. spontaneum parents is a potential problem. In our earlier studies, we demonstrated that emasculation of mature S. spontaneum flowers through hot water treatment does not guarantee pollen stertility and that self-pollination of the maternal S. spontaneum parents can occur. Therefore, some of the total 1,971 progeny from these interspecific crosses were expected to be selfed S. spontaneum. To identify selfed S. spontaneum, we used three microsatellite markers (SMC334BS, SMC336BS, and MCSA068G08) to screen all the 1,971 progeny while they were seedlings in the greenhouse. Based on the microsatellite fingerprints, four classes of progeny (A, B, C, or D) were identified. Class A produced alleles of both parental origins to be considered as genuine F1 progeny. Class B produced allele(s) of the paternal variety only and was either selfed or F1 hybrid progeny. Class C produced alleles of both the maternal S. spontaneum parent and an unknown source and therefore was a contaminant. Class D produced allele(s) of the maternal S. spontaneum parent only and was either selfed or F1 hybrid progeny. Cross 01-3242 (IMP9834 x HoCP96-540) had only 5 progeny and was excluded from the following statement. The percentages of each class varied from cross to cross, 26 to 96% for the A Class, 0 to 52% for the B Class, 0 to 32% for the C Class, and 0 to 53% for the D Class. Ten seedlings of the A Class from each cross were selected for further backcrossing in 2002. The remaining progeny were transplanted into the breeding nursery to verify the results from the molecular classification.