Graduate Thesis Or Dissertation
 

Use of combining ability estimates to identify the genetic potential of selected winter parental lines (Triticum aestivum L.em Thell)

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/qv33rz99d

Descriptions

Attribute NameValues
Creator
Abstract
  • A major factor limiting the efficiency of plant improvement programs is the lack of knowledge as to which parental combinations to make when working with quantitatively inherited traits. The primary objective of this study was to provide information regarding the use of combining ability analysis to predict which cross combinations would result in the greater frequency of desirable segregates. Five winter wheat parents were used to develop a 5x5 diallel cross. Over a two year period parents, Fl, F2, F3, and F4 generations involving top cross populations were evaluated. Information was collected on an individual plant basis for seven traits: plant height, tiller number, spike length, spikelets per spike, biological yield, grain yield, and harvest index. Griffing's (1956) model 1, method 2 was used to estimate GCA and SCA in Fl and later generations. Narrow-sense heritability estimates were computed using regression in standard units across generations. Significant GCA estimates were obtained for most traits in all generations with the exception of tiller number and grain yield in the Fl during 1986-87. Specific combining ability estimates were also found to be important for all traits, except spikelets per spike in the Fl and F3 generations. High GCA to SCA ratios indicated a preponderance of additive gene action. Exceptions to the trend were grain yield and tiller number in the Fl during 1986-87. Low GCA and narrow-sense heritability estimates suggest that selection for these two traits would have to be delayed until later generations. When considered over generations, both GCA and SCA estimates were found to be significant. Significant SCA over generations indicated the presence of additive x additive epistasis. The GCA effects contributed by a particular parent were consistent over all generations indicating that F2 and F3 generations can be used effectively for combining ability analysis. However, the results did suggest that GCA estimates were more influenced by the environment than SCA. For the traits measured and in the populations used in this study, GCA effects did predict the best parental combinations for obtaining the highest percentage of desirable progeny in segregating populations.
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, 8-bit Grayscale) using ScandAll PRO 1.8.1 on a Fi-6670 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 MasoodMuhammadS1989.pdf 2017-08-04 Public Download