Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/14/2006
Publication Date: 4/24/2006
Citation: Tew, T.L., Pan, Y. 2006. Microsatellite-based paternity analysis of a seven-parent sugarcane polycross [abstract]. In: 8th International Society of Sugar Cane Technologists Breeding and Germplasm Workshop Abstract Book, May 1-5, 2006, Guayaquil-Ecuador. p. 5.
Technical Abstract: It is virtually impossible to make all cross combinations among even the most elite parents used in breeding programs. Hence, the polycross approach has been used in sugarcane breeding to maximize the number of cross combinations that could be represented among progeny at the seedling stage of testing. The primary objection to using the polycross approach has been the rapid loss of pedigree information that occurs over generations of breeding. Microsatellite-based paternity analysis is proposed as an effective means for identifying the male parentage of progeny resulting from small polycrosses. We provide a preliminary report on our experience in analyzing a polycross involving seven parents. The two microsatellite markers that produced the greatest number of polymorphic fragments or alleles, namely SMC336BS and SMC597CS, were used to genotype a sample of 87 progeny from each female parent. We used 96-well plates which consisted of the 87 progeny, the seven parents plus positive and negative controls. The two markers produced ten (9 polymorphic) and eleven (10 polymorphic) alleles, respectively. These 19 discriminating alleles allowed us to positively identify the male parentage of 51% (ranging from 35-70% depending on the female parent) of the progeny from this polycross and to obtain a workable estimate of the relative pollen contribution of each male parent per female parent used in the polycross. Estimated contribution of the most dominant male ranged from 14 – 53% across female parents. Small polycrosses accompanied with microsatellite marker genotyping technology can be used in a sugarcane breeding program to maximize desired parental combinations at a minimal loss in parental information.