Identification and Characterisation of the Barley Row-Type Gene <i>VRS3 </i>

Barley row-type describes the number of grains present at a node on the barley spike. Two forms exist amongst cultivated barley: two-rowed with only the central of three spikelets fertile producing a single grain at a node and six-rowed with all three spikelets fertile, producing three grain at a node. Twelve regions of the barley genome have been associated with the row-type character with specific genes identified at three loci, <i>VRS1</i>, <i>VRS4</i> and <i>INT-C</i>. Advancements in the understanding of the genetic control underpinning barley row-type enables the identification of potential mechanisms for improving yield and yield architecture within the cereals. <br/>This study used genetic linkage mapping in segregating F2 populations to refine the genetic location of the row-type locus, <i>VRS3</i>, to 16 candidate genes on barley chromosome 1H. Sequencing candidate loci in 32 <i>vrs3</i> induced mutant alleles identified <i>VRS3</i> to be a highly conserved JmjC histone demethylase, with two natural alleles within European cultivated barley. <i>VRS3</i> was further characterised as a potential means of improving grain uniformity within cultivated six-rowed barley, through phenotypic assessment of grain size in varying allele combinations of <i>VRS3</i>, <i>VRS1</i> and <i>INT-C</i>. The addition of six-rowed alleles at these loci was found to improve balance between central and lateral grain parameters, resulting in a more uniform grain sample. Analysis of gene expression found <i>Vrs3</i> to be constitutively expressed across a diverse panel of barley tissues. Moreover, detailed study within the developing inflorescence suggests a role for <i>Vrs3</i> in the regulation of the row-type genes <i>VRS1</i> and <i>INT-C. </i>

Name dc:type.qualificationname

Doctor of Philosophy

Level dc:type.qualificationlevel

Doctoral Thesis

Year dc:date.issued

2015

Author dc:creator

• Bull, Hazel Joanne

Advisors dc:contributor.advisor

• Waugh, Robert
• Thomas, Bill

• Barley
• Genetics
• Row-type
• Inflorescence
• Morphology

Language dc:language

eng

Identifier

oai:discovery.dundee.ac.uk:studenttheses/be5f6de8-4245-45e3-bb17-649f7d724f55

OAI identifier oai:identifier

oai:discovery.dundee.ac.uk:studenttheses/be5f6de8-4245-45e3-bb17-649f7d724f55