Submitted to: Germplasm Release
Publication Type: Germplasm Release
Publication Acceptance Date: October 20, 1999
Publication Date: N/A
Interpretive Summary: This is a germplasm release. No Interpretive Summary is needed.
Technical Abstract: SR93 is a highly smoothroot sugarbeet selected for soil-free harvest. It has root smoothness equivalent to SR87 released in 1990, but with an improved breadth of genetic base. SR93 is an increase of seed produced by open pollination of twelve smoothroot selections resulting from two cycles of mass selection for root smoothness in a population derived from a series sof pair-crosses among plants without selection for root smoothness. The series started with a sulfonylurea herbicide resistant regenerant plant, from callus of clone REL-1, crossed to a single plant of EL48. A single sulfonylurea herbicide resistant progeny plant was crossed to a plant of smoothroot line SP85700. Two herbicide resistant progeny plants from that mating were pair-crossed to two plants from high sucrose line L19. Four herbicide resistant plants from the resultant progenies were pair-crossed to SR87, producing the four families that entered the two smoothroot mass selection cycles. The twelve foundation plants chosen at the end of the second cycle of mass selection were sulfonylurea herbicide susceptible. The parentage of SR93 is 50% SR87, 25% L19, 12.5% SP85700, 6.25% EL48, and 6.25% REL-1. SR93 is diploid multigerm and segregates for red and green hypocotyl color. SR93 is relatively easy bolting, and self-sterile with a significant degree of pseudo-self-fertility under individual plant isolation.