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

Salsomaggiore Terme, Italy - 26/29 September, 2001

ISBN 88-900622-1-5

Poster Abstract

QT LOCI REGULATING THE ACCUMULATION OF THE COR14B AND TMC-AP3 COLD-INDUCED PROTEINS IN BARLEY

FRANCIA E., CROSATTI C., PECCHIONI N.

Istituto Sperimentale per la Cerealicoltura Sezione di Fiorenzuola, Via S. Protaso 302, 29017 Fiorenzuola d'Arda (PC)

n.pecchioni@iol.it

barley, COR genes, gene regulation, QTL analysis, cold stress

One of the most important limiting factors of barley and other straw cereals is the cold stress during the winter season. The capacity of barley plant to survive to these conditions is associated to the well-known phenomenon of hardening. During the hardening period, when the cereal "feels" the advent of the winter season, a relatively great number of COR (cold-regulated) genes are expressed. Many studies exist about the COR gene cloning and the accumulation of single COR transcripts. In parallel, some genetic studies of the winterhardiness trait in the Triticeae lead to identify few genomic regions playing an important role in the tolerance to low temperatures, particularly on homoeologous group 5 of Triticeae.

It was aim of this work a genetic study of the regulation of the accumulation of two COR proteins in barley. To do this, we investigated by Western analysis the differential accumulation of the COR proteins COR14b and TMC-AP3 in a barley doubled haploid (DH) mapping population in field conditions during the winter season 2000/01. A SSR, STS and AFLP map had been previously constructed on the same segregating population, deriving from the "winter x spring" barley cross "Nure x Tremois". The parent cultivars showed a clearly differential accumulation of the two COR proteins in the field, and QT loci regulating their accumulation have been mapped. Freezing tolerance data have also been recorded for the DH lines in controlled environment (phytotron), and QTLs of freezing tolerance have been mapped on the barley genome. The genetic analysis of protein accumulation analysis allowed us to identify two regions involved in the regulation of both genes, COR14b and TMC-AP3, on the long arm of barley chromosome 7(5H), and to compare their position with the freezing tolerance QTLs. In conclusion, these results allowed us to correlate genetic informations and molecular data on cold stress, and gave a new insight into the genetic components that are responsible of winterhardiness in the barley crop.