Registration of FC1740 and FC1741 Multigerm, Rhizomania‐Resistant Sugar Beet Germplasm with Resistance to Multiple Diseases

FC1740 (Reg No. GP-293, PI 681717) and FC1741 (Reg No. GP-294, PI 681718) sugar beet germplasm (Beta vulgaris L.) were developed by the USDA-ARS at Fort Collins, CO, Salinas, CA, and Kimberly, ID, in cooperation with the Beet Sugar Development Foundation, Denver, CO. These germplasm are diploid, multigerm sugar beet populations in normal cytoplasm, segregating for self-sterility (Sf:SsSs), genetic male sterility (A:aa), and hypocotyl color (R:rr). FC1740 and FC1741 have excellent resistance to rhizomania (Beet necrotic yellow vein virus). FC1740 was selected as homozygous resistant to markers linked to both Rz1 and Rz2 genes for rhizomania resistance. FC1741 was selected as homozygous to the marker linked to the Rz2 gene for resistance. Both germplasm also have resistance to beet curly top (Beet curly top virus) and Fusarium yellows (Fusarium oxysporum Schlechtend.:Fr. f. sp. betae (D. Stewart) W. C. Snyder & H. N. Hans. and other Fusarium spp.), as well as moderate resistance to Aphanomyces root rot (Aphanomyces cochlioides Drechs.). Neither line exhibited resistance to Cercospora leaf spot (Cercospora beticola Sacc.), Rhizoctonia crown and root rot (Rhizoctonia solani Kuhn.) or sugar beet root aphid (Pemphigus spp.). These germplasm provide sources from which to select disease-resistant, multigerm pollinator parents with either or both of the Rz1 and Rz2 sources of rhizomania resistance. Because they are from the same population, they also are useful as controls of known genetic background in comparing entries screened for rhizomania resistance conditioned by Rz1 or Rz2.