Understanding the developmental basis of grain yield potential in bread wheat

Gonzalez Navarro, Oscar (2017) Understanding the developmental basis of grain yield potential in bread wheat. Doctoral thesis, University of East Anglia.

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Abstract

Grain yield potential in wheat is a complex trait controlled by sub-traits like grain
number, grain size, and assimilate partitioning. To achieve further understanding of
grain yield potential, this thesis combines physiological and genetic dissection of
wheat development. In particular, how the length of developmental phases can be
optimized in favour of increased partitioning of assimilates to the spike, in order to
reduce abortion rates of florets.
The physiological section of the thesis (Chapter 2 and 3) comprises the in depth study
of the CIMCOG panel (CIMMYT Core Germplasm). In this section the variation in
patterns of floret and phenological development was determined, ascertaining how
these differences affect the number of fertile florets. The differences in floret
development were clear in the intermediate florets (floret primordia 3, 4, and 5 from
the rachis). Floret survival was found to be positively related to the length of the period
of floret development. Also fruiting efficiency, using the frontier concept, show a
positive relationship with the stem elongation period.
The genetic section (Chapter 4 and 5) involves the use of quantitative trait locus (QTL)
analysis with a segregating population to determine the chromosomal locations
affecting key developmental traits. A Buster x Charger doubled haploid population
provided a crucial contrast between similar genetic background and differences in
length of phenological phases. The results show that a QTL on chromosome 7A has
an effect on the time to terminal spikelet phase, i.e. the onset of stem elongation, and
QTL affecting time to heading was found on chromosomes 2D and 4A. Furthermore,
this population also varies in lodging resistance. A major QTL was found on
chromosome 2D affecting height and providing lodging resistance.
These studies provide the basis to optimise wheat developmental patterns and,
therefore, maximize spike fertility.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Science > School of Biological Sciences
Depositing User: Jackie Webb
Date Deposited: 29 Mar 2017 09:31
Last Modified: 29 Mar 2017 09:31
URI: https://ueaeprints.uea.ac.uk/id/eprint/63110
DOI:

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