Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Oral Communication Abstract - S2b

TRACING FUNCTIONAL POLYMORPHISMS THROUGH BARLEY BREEDING HISTORY

P. DONINI, E. CHIAPPARINO, D. O’SULLIVAN

NIAB, Huntingdon Road, CB3 0LE, Cambridge - UK

SNP, association mapping, functional polymorphisms, beta-amilase, barley

We have initiated a study on trends in genetic diversity in recent European barley breeding programmes using a sample of 500 cultivated barley varieties representing a large proportion of the acreage sown to barley in the EU over the last 60 years.

As a contrast to neutral marker studies, we decided to make a survey of functional polymorphisms in genes known to have been the target of selection in breeding programmes. We will present a case study of haplotype diversity in the endosperm-specific Beta-amylase 1 gene of barley on chromosome 4H, encoding a starch-degrading enzyme crucial to the malting quality characteristics of the barley. SNP genotyping allowed us to detect novel haplotypes which were confirmed by resequencing the relevant fragments of the coding sequence. The predicted functional significance of the observed haplotypic diversity will be discussed, as will the transmission of particular alleles through known pedigrees.

This approach has considerable power to give a retrospective analysis of barley breeding prior to the molecular marker era.

Finally, we examine the feasibility of using phenotypically well characterised cultivated varieties for association mapping of traits for which the genetic basis is as yet unknown by augmenting the few known functional polymorphisms with an appropriate density of genome-wide random polymorphisms.