Maize Dwarf Mosaic Virus in Zea Mays L.: Inheritance of Resistance, Yield Loss, Serology, and Seed Transmission

125 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983.The effect on sweet corn yield of inoculation with maize dwarf mosaic virus (MDMV) at the three-leaf, eight-leaf, or just prior to silking was examined. Early infection delayed maturity, reduced yield and plant height. Little difference was found between the late inoculation and the inoculated control.No source of MDMV resistance was found in sugary corn as a result of screening 510 genotypes. The following field corn inbreds were found as highly MDMV resistant: Pa405, B68, Oh1EP, Ga209. Evaluation of F1 hybrids of susceptible sugary corn (su) x resistant dent corn showed Pa405 as the best MDMV resistant parent.Testcross (TC) (su x (su x Pa405)F1) and F2 (su x Pa405)F2 progeny were examined for MDMV disease response, and both fit a three gene model where one gene must be present with either of the other two. In TCF2 and TCF3 progeny, selfed from resistant parents in the previous generation, were observed. The TCF2 were 55% resistant versus 61% resistant plants expected based on a three gene model. The TCF3 progeny were 69% resistant versus 72% resistant plants expected based on a three gene model. The number of 100% MDMV resistant TCF3 lines found was 5 of 43 lines when the expected based on a three gene model was 6 homozygous lines. TC (su x (su x B68)F1) and F2 (su x B68)F2 progeny were examined for MDMV disease response, and both fit a three gene model where all three genes must be present. In all the previous MDMV segregates resistance segregated independently of the su/Su allele.In studies of MDMV IgG in the enzyme-linked immunosorbent assay (ELISA), IgG coat was reused after pretreatment in low pH glycine-HCl buffer. IgG-AP from previous assays was reused in subsequent assays to conserve ELISA IgG.MDMV was found to be seed transmitted in 1 of 22189 sweet corn seedlings. MDMV was not detected in pollen by infectivity, ELISA, or serological specific electron microscopy. MDMV was detected at a high rate in pericarp and at lower rates in endosperm and embryo samples 21 days after pollination. In mature seeds MDMV was rarely detected in the seed parts, and never detected in the embryo.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD