Inheritance mechanism and QTL mapping of powdery mildew resistance in Cornus florida
LIPI PARIKH. Inheritance mechanism and QTL mapping of powdery mildew resistance in Cornus florida (under the guidance of Dr. Margaret Mmbaga) Cornus is a large genus of trees and shrubs that are collectively referred to as dogwoods. Flowering dogwoods (Cornus florida) especially is an economically important ornamental tree with 30 million dollars in annual total sales; 23.2% of the total US dogwood supplies come from Tennessee. Powdery mildew disease on Cornus florida is considered one of the most destructive diseases in nursery production throughout the Southeastern US. Efforts to breed for resistance have been slow and only a few cultivars have been rated resistant. In this study Powdery mildew resistance was investigated using Pseudo F2 populations derived from controlled crosses between phenotypically distinct parents, Cherokee Princess (Susceptible), MI9 and R14 (Resistant selections). Disease severities as recorded for parental clones and progeny populations showed continuous disease distribution. This indicated quantitative inheritance of powdery mildew resistance in C. florida. Heritability and genetic gains were estimated for selection of genetically desired parents. Identification of microsatellite markers/ QTL that may be linked to resistance in the segregating progeny population was also conducted with 105 markers. Genetic maps were then constructed for the two Pseudo-F2 populations with JoinMap 4.1. This information is important in marker assisted breeding programs for breeding for resistance in dogwoods.
Biology|Molecular biology|Plant sciences
"Inheritance mechanism and QTL mapping of powdery mildew resistance in Cornus florida"
ETD Collection for Tennessee State University.