The allelic composition at five glutenin loci was assessed by one-dimensional sodium dodecyl sulphate
polyacrylamide gel electrophoresis (1D SDS–PAGE) on a set of 155 landraces (from 21 Mediterranean countries)
and 18 representative modern varieties. Gluten strength was determined by SDS-sedimentation on samples grown
under rainfed conditions during 3 years in north-eastern Spain. One hundred and fourteen alleles/banding patterns
were identified (25 at Glu-1 and 89 at Glu-2/Glu-3 loci); 0·85 of them were in landraces at very low frequency and
0·72 were unreported. Genetic diversity index was 0·71 for landraces and 0·38 for modern varieties. All modern
varieties exhibited medium to strong gluten type with none of their 13 banding patterns having a significant effect
on gluten-strength type. Ten banding patterns significantly affected gluten strength in landraces. Alleles Glu-B1e
(band 20), Glu-A3a (band 6), Glu-A3d (bands 6+11), Glu-B3a (bands 2+4+15+19) and Glu-B2a (band 12)
significantly increased the SDS-value, and their effects were associated with their frequency. Two alleles, Glu-A3b
(band 5) and Glu-B2b (null), significantly reduced gluten strength, but only the effect of the latter locus could be
associated with its frequency. Only three rare banding patterns affected gluten strength significantly: Glu-B1a
(band 7), found in six landraces, had a negative effect, whereas banding patterns 2+4+14+15+18 and
2+4+15+18+19 at Glu-B3 had a positive effect. Landraces with outstanding gluten strength were more frequent
in eastern than in western Mediterranean countries. The geographical pattern displayed from the frequencies of
Glu-A1c is discussed.R. Nazco was recipient of a Ph.D. grant from the
Comissionat per Universitats i Investigació del
Departament d’Innovació, Universitats i Empresa of
the Generalitat of Catalonia and the Fondo Social
Europeo. This study was partially funded by CICYT
under projects AGL2006-09226-C02-01, AGL2009-
11187 and AGL2012-37217 and was developed
within the framework of the agreement between INIA
Spain and CIMMYT. The Centre UdL-IRTA is part
of the Centre CONSOLIDER INGENIO 2010 on
Agrigenomics funded by the Spanish Ministry of
Education and Science. CRF, ICARDA and USDA
Germplasm Bank are acknowledged for providing
accessions for the present study.info:eu-repo/semantics/publishedVersio
