Variation of morphological and agronomical traits, and protein composition in durum wheat germplasm from eastern Europe

Broadening the genetic base upon which the breeding of durum wheat relies is a growing concern in Italy. Exotic materials can represent valuable sources of adaptive features and they have been repeatedly exploited in the past for direct utilisation and/or introgression by crossing into existing germplasm. An increase of the available genetic variation for the breeding also appears envisageable in terms of end-product quality. This study assessed the variation in germplasm from eastern Europe countries, which could represent novel gene sources for durum wheat improvement in Italy, and verified the presence of variants of potential interest for agronomical and quality characteristics to be possibly exploited for breeding. Fifty-nine landraces from the former USSR and 91 from Bulgaria were grown in Sicily and evaluated for agronomical traits, spike morphological characteristics (possibly bearing some taxonomic relevance), and protein composition at three loci encoding for glutenin subunits responsible of flour quality features. The results suggested a similar overall diversity in the two groups considering either the variance of the agronomical characters, or the diversity index (H') across morphological traits, or the frequency distribution of electrophoretic patterns of glutenin subunits encoded at three loci. Genotypes of potential usefulness as donors of positive agronomical or quality attributes were found in both germplasm groups, although the agronomical characteristics of the exotic genotypes rarely matched those required by the breeding in the target area. Conversely, the genetic variation found at the three loci involved in the composition of glutenin subunits appeared of greater relevance for the breeding in Italy.