Submitted to: Journal of Plant Registrations
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/18/2007
Publication Date: 9/1/2007
Citation: Guo, B.Z., Widstrom, N.W., Lee, R.D., Coy, A.E., Lynch, R.E. 2007. Registration of maize germplasm GT601 (AM-1) and GT602 (AM-2). Journal of Plant Registrations. 1(2):153-154. Interpretive Summary: Not required.
Technical Abstract: GT601 (Reg. no. xxxx, PI xxxx) and GT602 (Reg. no. xxxx, PI xxxx) are yellow dent maize (Zea mays L.) lines developed and released jointly by the USDA-ARS Crop Protection and Management Research Unit and the University of Georgia Coastal Plain Experiment Station in 2006. GT601 and GT602 were developed by seven generations of self-pollination from a maize population GT-MAS:gk (McMillian et al., 1993). This maize population was derived and selected from a visibly segregating hybrid ear that was infected by Aspergillus flavus (Widstrom et al., 1987) for reduced aflatoxin contamination. McMillian et al. (1993) released this maize population GT-MAS:gk as a source of resistance to aflatoxin accumulation. In order to utilize the resistance traits from GT-MAS:gk, e.g. physical pericarp wax (Guo et al., 1995, 1996; Russin et al., 1997) and antifungal proteins (Guo et al., 1997, 1998; Chen et al., 1998), efforts of self-pollination and selection have been made since 1996 for reduced aflatoxin contamination. By evaluating S1 families, Guo et al. (2001) demonstrated that considerable variation among the individual plants within the population GT-MAS:gk was detectable using RAPD markers and laboratory aflatoxin bioassay. Guo et al. (2002) also evaluated S5 generation using 113 RFLP probes for genetic variation and conducted two year field tests for aflatoxin contamination. The aflatoxin concentrations and maturity data among the S5 lines were significantly different (Guo et al., 2002). Evaluation for aflatoxin contamination in 2004 and 2005, GT601 (GT-A1-1) had 33 ng g-1 and 62 ng g-1, and GT602 (GT-P56) had 32 ng g-1 and 51 ng g-1, respectively, while resistant control Tex6 (Hamblin and White, 2000) had 69 ng g-1 and 120 ng g-1. In 2005 hybrid test, GT601 x Cy1 and GT602 x Cy1 had 113 ng g-1 and 105 ng g-1 aflatoxin, whereas the commercial hybrid controls had up to 266 ng g-1 aflatoxin. GT601 and GT602 are adapted to southeastern U.S. region. GT601 flowers about 10 days earlier than GT602, with about 60 days and 70 days from planting to flowering, respectively. GT601 has colorless pericarp, white cob, and browning silk, P-wwb, and GT602 has colorless pericarp, red cob, and browning silk, P-wrb. GT601 had been used in genetic QTL mapping studies for silk maysin production (Butrón et al., 2001) and A. flavus infection (Widstrom et al., 2003). In 2004 and 2005 field evaluation, GT602 had moderate disease resistance to southern leaf blight and leaf rust, but GT601 was susceptible to both diseases. Seeds of GT601 and GT602 will be maintained and distributed by the USDA-ARS, Crop Protection and Management Research Unit, Tifton, GA, upon written request to the corresponding author.