|NOTICE OF RELEASE OF FC201 MONOGERM, O-TYPE SUGARBEET GERMPLASM WITH RESISTANCE TO RHIZOMANIA AND OTHER DISEASES|
The USDA Agricultural Research Service (ARS), in cooperation with the Beet Sugar Development Foundation (BSDF), announces the release of FC201 sugarbeet germplasm. This germplasm was developed in the breeding programs of Drs. Lee Panella and R. T. Lewellen, USDA-ARS, Fort Collins, Colorado, and Salinas, California. FC201 is a segregating population with a high frequency of the Rz allele conferring resistance to rhizomania caused by Beet necrotic yellow vein virus. It is segregating for resistance to root-rotting strains (AG-2-2) of Rhizoctonia solani K?hn and to the sugar beet root aphid (Pemphigus sp.), has moderate resistance to cercospora leaf spot caused by Cercospora beticola Sacc., to black root caused by Aphanomyces cochlioides Drechsl., and the Beet curly top virus. FC201 is a heterogeneous population from which to select disease resistant monogerm, O-type parents to infuse multiple disease resistance on the female side of hybrids. There is no CMS equivalent. FC201 is released from Salinas seed production 01-FC1014 and has been tested as 00-FC1014 and 01-FC1014.
FC201 is an O-type germplasm segregating for hypocotyl color (R) and for monogerm (mm). It is the F4 of the cross 'C890'aa x ' FC708' (23 F1 plants) bulked with the cross 'C859'aa x ' FC708' (18 F1 plants). Seed from both F1 populations was combined for bulk increase of the F2 after germination testing to make the parental contribution 25% from C890, 25% C859, and 50% FC708. The F2 seed was planted in Salinas and selected for rhizomania resistance, agronomic performance, and percent sucrose. The F3 population was a bulk increase of 25 plants selected from 600 grown in the field under severe rhizomania conditions and increased in the greenhouse. Seed from the F3 was sent to Oregon for steckling production and the F4 was an increase at Salinas without selection of about 250 stecklings; seed from only male-sterile plants was harvested. Half-sib family grow-outs indicated that the male-sterility was genetic male-sterility (aa) and genetic-cytoplasmic male-sterility (CMS). Progeny testing could be used to identify and separate genetic-male sterility from CMS and to produce a near equivalent CMS counterpart to the male fertile, O-type.
When tested at Fort Collins, CO, in 2003 for resistance to rhizoctonia root rot under strong disease pressure, the FC201 population was not significantly different from the susceptible check, but individual roots were scored as resistant, i.e. DI < 3 (DI of 0 = no root rot and 7 = all plants dead). In a greenhouse test for resistance to sugarbeet root aphid at Shakopee, MN, in 2003, again, although the population was not different from the susceptible control there were a number of roots which were scored as 1 (1 = free from aphids to 4 = heavily infested with aphids).
When tested in Fort Collins, CO, and Rosemount, MN, in 2002 and 2003 for resistance to cercospora leaf spot, the scores were intermediate (significantly more resistant than the susceptible check and significantly less resistant than the resistant check). The same intermediate resistance was seen when tested at Shakopee, MN, in 2002 and 2003 for resistance to Aphanomyces root rot. In the BSDF curly top nursery at Kimberly, ID, in 2003 FC201 had a DI of 5.0 over three replications (not statistically analyzed) compared to 'US H11' with a DI of 3.3 and 'Monohikari' with a DI of 7.0 (1 = no damage to 9 = plant dead). When FC201 was tested for O-type, restorer genes were present only at a very low frequency.
In observation and evaluation tests at Salinas in 2002 and 2003, FC201 was moderately susceptible to powdery mildew caused by Erysiphe polygoni DC; intermediate in reaction to Erwinia root rot caused by E. carotovora betavasculorum Thomsen et al. with 60 - 70% resistant plants; and moderately susceptible to intermediate for bolting tendency in fall plantings. Sucrose concentration was intermediate to a group of monogerm populations and inbred lines. The canopy of FC201 is dark green with leaf shape similar to FC708.
Breeder seed of FC201 is maintained by USDA-ARS and will be provided in quantities sufficient for reproduction upon written request to Sugarbeet Research, USDA-ARS, Crops Research Laboratory, 1701 Center Ave., Fort Collins, CO 80526-2083. Genetic material of this release will be deposited in the National Plant Germplasm System where it will be available for research purposes, including development and commercialization of new varieties/cultivars. We request that appropriate recognition be made of the source when this germplasm contributes to a new cultivar. U.S. plant variety protection will not be requested for FC201.
Acknowledgement: Tests at Shakopee and Rosemount, MN were run by Betaseed, Inc. by M. Rekoske and J. Miller, and reaction to BCTV was tested in the BSDF nursery at Kimberly, ID