6.04 - Società Italiana Genetica Agraria

Proceedings of the 54th Italian Society of Agricultural Genetics Annual Congress
Matera, Italy – 27/30 September, 2010
ISBN 978-88-904570-0-5
Oral Communication Abstract – 6.04
TOWARDS THE FINE MAPPING OF A MAJOR QTL ON CHROMOSOME
3BS FOR YIELD AND PLANT VIGOUR IN DURUM WHEAT
GRAZIANI M.*, MACCAFERRI M.*, SANGUINETI M.C.*, PAUX E.**, SALSE J.**,
CHOULET F.**, FEUILLET C.**, STEFANELLI S.*, DEMONTIS A.***, TUBEROSA R.*
*) Dept. of Agroenvironmental Science and Technology (DiSTA), University of Bologna, Viale
Fanin 44, 40127 Bologna (Italy)
**) Institut National de la Recherche Agronomique, UMR INRA-UBP 1095 Génétique, Diversité et
Ecophysiologie des Céréales, Domaine de Crouelle 234, 63100 Clermont-Ferrand (France)
***) Società Produttori Sementi di Bologna PSB, 40050 Argelato (Bologna, Italy)
Durum wheat (Triticum durum Desf.), molecular and phenotypic characterization, synteny,
heterogeneous inbred families, BAC-end sequences
Two major QTLs (QYld.idw-2B and QYld.idw-3B) for yield, yield components and other
morpho-physiological traits related to plant vigour and crop productivity (e.g. ear peduncle length,
plant height and leaf senescence rate) were identified in durum wheat on the distal regions of
chromosomes 2BL and 3BS in a RIL population obtained from the cross Kofa x Svevo (Maccaferri
et al. 2008; Genetics 178: 489-511). Our objective is to fine map and eventually clone the two
QTLs. Fine mapping of QYld.idw-3B is underway in the framework of the FP-7 TriticeaeGenome
project, where chromosome 3B is being physically mapped, sequenced and annotated.
As a first step, a set of 19 pairs of F5:7 near isogenic lines (heterogeneous inbred families,
HIFs) have been developed from the residual heterogeneity present in the original population. The
19 HIF pairs are being evaluated for yield and morpho-physiological traits related to the QTL in
replicated field trials. The QTL effect on plant height has been detected in most HIFs. Yield data,
not yet available, will be presented.
In parallel, molecular markers have been added to the QTL region by using BAC end-derived
SSRs and retrotransposon (ISBP)-based loci. Twenty-three SSRs and 8 ISBPs have been mapped
within an interval of 11 cM including the QTL peak. The relevant BAC contig (no. 954, 3156 kblong) has been sequenced and annotated. This contig has been shown to contain 41 genes and 8
pseudogenes that will be used as new marker source and for candidate gene analysis.
A large population of ca. 5.000 F2 individuals derived from four HIF pairs has been grown
and sampled to identify novel recombinant events in the target region harbouring the QTL.