Submitted to: Journal of Plant Registrations
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 30, 2010
Publication Date: February 21, 2011
Citation: McGrath, J.M. 2011. Registration of EL54 and EL55 sugarbeet germplasms. Journal of Plant Registrations. 5:1-6. Interpretive Summary: Germplasm forms the basis for continued improvement of plant varieties. Each germplasm is a unique combination of traits and characters that, alone or in combination, addresses a real or perceived limitation in the genetic performance of current varieties. The sugar beet germplasms released here, EL54 and EL55, have a diverse set of traits that are not integrated into the majority of sugarbeet varieties. EL54 has a particular advantage in meeting performance limitations caused by the root and seedling pathogen Aphanomyces. This trait comes from a wild species crossed with sugar beet and selected for sucrose yield improvement. EL55 has a set of characters that appears to improve seed longevity in storage. These germplasms will find use in breeding new varieties and hybrids for increased efficiency of sugar beet production.
Technical Abstract: EL54 (PI 654357) is a sugarbeet germplasm derived from wild beet (Beta vulgaris ssp. maritima) accession WB879 (PI 540625), released in the interest of broadening the genetic base of sugar beet. The parent accession WB879, collected in 1989 from Port-de-Houet, France. EL54 has shown excellent Aphanomyces resistance in field trials in Michigan, Minnesota, and North Dakota. The pedigree of EL54 includes twenty WB879 plants and SP6822 (PI 615525), and roots were selected based on the absence of lateral rootlets (i.e. sprangles) and freedom from disease. EL54 has consistently shown excellent Aphanomyces resistance (mean score = 2.4, sd. = 0.6 compared with means of resistant checks = 2.8, sd. = 1.1; scored on a scale of 1 to 8 where 1 is healthy and 8 is severely rotted at the end of the season). EL54 has shown an average sucrose percentage of 14% (sd = 2.2) and a yield of 25.1 tons / acre (sd = 6.9). This compares at 82% of the sucrose percentage and 93% of the yield of the commercial check. EL55 (PI 655304) is a sugarbeet germplasm derived from seed held in sub-optimal storage conditions at East Lansing for 20+ years, and was released in the interest of improving seed quality and performance in sugar beet. From over 4,000 legacy seedlots produced between 1961 and 1989 stored in ambient (high humidity) conditions, only 71 of these stored seedlots gave commercially adequate stands. Roots from the 12 oldest seedlots (i.e. those stored the longest) were collected as mother roots, and seed was produced. Using an accelerated seed aging protocol, this seed demonstrated slightly improved seed longevity. The majority of this germplasm is derived from remnant seed generated during development of seed parents in the germplasm conversion to hybrid seed production. The parentage of EL55 is complex. Germplasm contributing to EL55 generally represents intermediate generations from a cross section of germplasm enhancement activities important during the development of modern hybrids. Compared with the standard check variety, EL55 showed 93% of the yield (24.4 versus 22.8 tons/acre for check and EL55, respectively), 80% of the sucrose percentage (check = 18.0 ± 0.5 % sucrose, EL55 = 14.5 ± 1.8 % sucrose), 105% of the % water content (check = 75.4 ± 1.8 % water, EL55 = 78.9 ± 1.7 % water), and 121% of the 30-day stand count.