THE INHERITANCE OF A NEW SOURCE OF RESISTANCE TO EXSEROHILUM TURCICUM (PASS) LEONARD AND SUGGS DERIVED FROM THE MAIZE (ZEA MAYS L.) VARIETY 'MAYORBELLA' (PI 209135)
Abstract
The corn (Zea mays L.) inbred H102 selected from the cross C123 x 'Mayorbella' is highly resistant to Exserohilum turcicum (Pass) Leonard and Suggs (northern corn leaf blight). To determine the inheritance of that resistance, H102 was crossed to four inbreds susceptible to northern corn leaf blight (NCLB) and to two inbreds with either the Ht or Ht2 gene for chlorotic lesion resistance to NCLB. The parents, F(,1)s, F(,2)s and backcrosses to the susceptible parent (BC1) were inoculated with spores of E. turcicum and rated for disease development using a 0 to 5 scale (completely resistant to completely susceptible, respectively) susceptible in field evaluations (1981 and 1982), and rated as resistant or susceptible in greenhouse evaluations (1982 and 1983). The F(,1)s of all crosses were resistant indicating that the resistance of H102 is partially dominant. Field and greenhouse evaluations of F(,2) and BC1 populations of H102 x susceptible crosses show the resistance of H102 to E. turcicum to be controlled by a single gene. Progeny of additional crosses of H102 x NN14A and NN14B, which carry the Ht and Ht2 genes for chlorotic lesion resistance, respectively, show the resistance in H102 to be controlled by a locus other than Ht or Ht2. Evidence is presented which suggests that the field resistance of H102 may be controlled by both monogenic and multigenic resistance, making H102 and the variety 'Mayorbella' desirable and durable sources of resistance to E. turcicum.
Degree
Ph.D.
Subject Area
Plant pathology
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.