PAG-V: P192 - GENETIC MAPPING OF RESISTANCE TO HIGH PLAINS VIRUS IN MAIZE

Plant & Animal Genome V Conference

Town & Country Hotel, San Diego, CA, January 12-16, 1997.

P192

GENETIC MAPPING OF RESISTANCE TO HIGH PLAINS VIRUS IN MAIZE

KAEPPLER, SHAWN MICHAEL(1), Alberto Marcon(1), Stanley Jensen(2)
1. Department of Agronomy, University of Wisconsin, 1575 Linden Drive, Madison WI 53706
2. Department of Plant Pathology, USDA, University of Nebraska, Lincoln NE 68583-0722

High Plains Virus (HPV) is a pathogen of maize and wheat causing severe disease symptoms on susceptible genotypes. The pathogen is vectored by the Eriophyid mite, Aceria tosichella, which is also the vector of wheat streak mosaic virus (WSMV). Maize and wheat plants in the field are often infected by both viruses. Thirty maize inbred lines have been evaluated for HPV disease development in the greenhouse, and resistant (e.g. B73 and B14), intermediate (e.g. Mo17), and susceptible (e.g. Wf9, W64A, B79, N194) genotypes identified. Resistance is dominant in F1 crosses of resistant x susceptible genotypes. A 3:1 resistant: susceptible ratio of F2 progeny was found in populations from the crosses B73xW64A and B73xWf9. The resistance locus maps to chromosome six, completely linked to BNL6.29 and wsm1. Resistance in a set of B73xMo17 recombinant inbred lines fit a two gene model. A resistance allele contributed by B73 mapped, as expected, to chromosome 6, and a resistance allele contributed by Mo17 mapped to chromosome 10, near UMC57 and wsm2. One-fourth of the population showed more disease symptoms than Mo17. A population derived from the cross B73xN194 is being used in an attempt to separate HPV and WSMV resistance effects. N194 is susceptible to HPV, but not to WSMV. F2 segregation in this population fit a 3:1 resistant:susceptible model for HPV, and a 15:1 resistant:susceptible model for WSMV. All plants susceptible to WSMV were also susceptible to HPV.