Registration of F1024 Sugarbeet Germplasm with Resistance to Sugarbeet Root Maggot

Abstract

F1024 (Reg. No. GP‐272, PI 658654) sugarbeet (Beta vulgaris L.) germplasm with resistance to sugarbeet root maggot (Tetanops myopaeformis von Röder) was released by the USDA‐ARS and the North Dakota Agricultural Experiment Station, North Dakota State University, Fargo, ND on 15 Dec. 2009. F1024 was selected from a population formed by crossing F1016, a germplasm line resistant to root maggot, with a breeding line resistant to Cercospora leaf spot (CLS; caused by Cercospora beticola Sacc.). The population was subjected to three cycles of mass selection for resistance to root maggot followed by three cycles of selection among half‐sib families. Under natural root maggot infestations, F1024 had a damage rating of 2.1 (on a scale of 1 to 9, where 0 = no maggot feeding, and 9 = >75% of root surface with feeding scars), compared with an average of 6.1 for two susceptible commercial hybrids. In a 2009 CLS evaluation, F1024 had a significantly lower disease rating than the susceptible check, and the difference between F1024 and the resistant checks was not significant. The performance of testcross hybrids between the component half‐sib families of F1024 and a susceptible cytoplasmic‐male‐sterile line provided additional validation of the potential of root maggot–resistant hybrids in areas where root maggot is a perpetual threat.