Dissertation
A PREDICTIVE GENETIC KNOWLEDGE FOR APPLE "FRESH SENSATION" PROVIDES INFORMATION TO INCREASE BREEDING EFFICIENCY IN WASHINGTON
Doctor of Philosophy (PhD), Washington State University
01/2014
Handle:
https://hdl.handle.net/2376/5081
Abstract
Apple texture and flavor are fruit quality components that determine the success of new apple cultivars and consumer satisfaction. Better-tasting apples encourage greater consumption and health benefits. The combined suite of traits of apple acidity (tartness), crispness, and juiciness is here termed "fresh sensation". The Washington State University Apple Breeding Program (WABP) is dedicated to developing new apple cultivars with improved "fresh sensation" among other attributes, and seeks to apply trait-predictive DNA tests to optimize breeding efficiency. Co-localized quantitative trait loci (QTLs) were previously reported for "fresh sensation" traits at the Ma locus of linkage group (LG) 16 of the apple genome. Two major alleles, Ma and ma associated with high and low acidity were identified in studies of biparental populations. Recently, the RosBREED project established resources (such as reference germplasm sets phenotyped with standardized protocols and genotyped with genome-wide single nucleotide polymorphism [SNP] markers), tools (such as Pedigree-Based Analysis software), and approaches (such as the "Marker-Assisted Breeding Pipeline") to characterize "fresh sensation" QTLs in breeding germplasm and develop predictive DNA tests. QTL analyses must be conducted to confirm the presence of contrasting alleles in WABP germplasm. Determination of SNP-based haplotypes associated with QTL alleles, their effects, and their distribution in the RosBREED WABP breeding germplasm will provide DNA information to support parent crossing decisions. Besides the Ma locus, other loci with genetic variation may also exist. This study seeks to confirm the presence of contrasting alleles at the Ma locus in RosBREED WABP breeding germplasm, and other QTLs for acidity as components of "fresh sensation", to determine the effects of each allele. A genome-wide QTL analysis was conducted using FlexQTLTM software. QTLs were validated at the Ma locus and on LG8, here called the "A" locus (for acidity). A QTL for crispness was also detected elsewhere on LG16. Relative effects of Ma and A haplotypes were calculated for each "fresh sensation" component. Three Ma alleles (Ma, ma and med) were identified at the Ma locus. The DNA information generated will help enable for marker-assisted parent selection to develop new apple cultivars using target levels of "fresh sensation" traits.
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Details
- Title
- A PREDICTIVE GENETIC KNOWLEDGE FOR APPLE "FRESH SENSATION" PROVIDES INFORMATION TO INCREASE BREEDING EFFICIENCY IN WASHINGTON
- Creators
- Sujeet Verma
- Contributors
- Cameron Paul Peace (Advisor)Kate Evans (Committee Member)Jim McFerson (Committee Member)Jim Luby (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Horticulture, Department of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 205
- Identifiers
- 99900581646501842
- Language
- English
- Resource Type
- Dissertation