Graduate Thesis Or Dissertation
 

Genetic mapping of Cuphea lanceolata : molecular-marker linkage to quantitative-trait loci affecting seed capric acid, seed oil, and embryo development

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/h128nj04k

Descriptions

Attribute NameValues
Creator
Abstract
  • Cuphea is an herbaceous genus having species whose seed storage lipids are predominantly medium-chain triglycerides (MCTs). Cuphea lanceolate Ait, and Cuphea viscosissima Jacq. are central to the breeding of Cuphea as a new commercial source of MCTs. The objectives of this thesis were to develop a reliable method to extract DNA from Cuphea, to construct a molecular-marker linkage map of C. lanceolate, and to evaluate quantitative-trait loci (QTL) affecting seed capric acid content, seed oil content, and embryo development in C. lanceolate. We used allozyme and restriction-fragment- length-polymorphism (RFLP) markers to study Cuphea because molecular markers are the best method available to investigate the Mendelian genetics underlying quantitative traits, and are useful in breeding. Adequate yield of clean DNA is essential for RFLP mapping. We tried numerous DNA extraction methods that failed to remove contaminants that interfere with restriction digests of Cuphea DNA. The method described here was developed to remove those contaminants and maintain relatively high DNA yields. In this method, the critical step in purification consists of washing the DNA with phenol while it is complexed with CTAB and dissolved in 1 M NaCl. An RFLP and allozyme linkage map of C. lanceolate was constructed having 37 markers in six linkage groups with a total distance of 288 cM. Levels of polymorphism were estimated for three lines of C. lanceolate and one line of C. viscosissima using 84 random genomic clones and two restriction enzymes, EcoRI and HindIII. Twenty-nine percent of the probes detected RFLPs between C. lanceolate lines, whereas 63% of the probes detected RFLPs between C. lanceolate and C. viscosissima lines. Thirty RFLP and four allozyme markers were used to locate on the C. lanceolata linkage map QTL affecting seed capric acid content, seed oil content, and embryo development. Three unlinked QTL explained 19.4% of the phenotypic variation in capric acid content in F₂ seed. Seed oil content and seed weight were measured on seed from field-grown F₂ plants. Seed weight was indicative of embryo size (development). Four unlinked QTL explained 33.9% of the phenotypic variation in embryo size. One of these QTL, which explained 20.3% of the variation, may have been a chromosomal deletion detected by a marker having a null allele. Three QTL pleiotropically affected seed oil by affecting embryo size. The one QTL that only affected seed oil accounted for 2.8% of the phenotypic variation.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using Capture Perfect 3.0 on a Canon DR-9050C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details WebbDavidM1991.pdf 2017-08-22 Public Download