Revisiting the ignored Ethiopian durum wheat (Triticum turgidum var. durum) landraces for genetic diversity exploitation in future wheat breeding programs

摘要

The majority of Ethiopian durum wheat are farmers’ varieties. Durum wheat varieties under production in Ethiopia are less productive due to the effect of climate change and marginalism of agricultural inputs. Recognizant to these, revisiting farmers varieties, ex-situ conserved, could be among the best options to adapt these changes. This study has thoroughly characterized a set of 49 durum wheat varieties to assess the level of phenotypic diversity through multivariate approaches for traits of importance. The study was aimed at estimating the extent of genetic diversity among the genotypes and to identify traits maximally contributing to the observed phenotypic variations. The statistical analyses have confirmed that the genotypes have shown very large (p<0.001) variations for most traits considered, except for number of effective tillers. The estimated broad – sense heritability (h2) has ranged from 20% for grain yield to 78% for spike length. The genotypes were grouped into six clusters with significant inter-cluster distances (χ2=15.51, p<0.05). The clustering revealed that the landraces are genetically far from the improved varieties. Genotypes consisted in a particular cluster are superior for a trait or more compared to the other clusters. For instance, genotypes in the first cluster are superior for grain and biomass yields. Early maturing and second high yielding genotypes were consisted in the fifth cluster. The genotype – by – traits biplot analysis has explained 82% of the total variation where 65.5% was explained by PC1, indicating that most of the observed variation is inherited. It can be concluded that the landraces are quite divergent from the improved varieties and the within landraces diversity was also high indicating that they represent important gene pool for important traits. Hence, revisiting landraces, which are Ex-situ conserved, and their exploitation in durum wheat breeding programs for grain yield improvement, earliness and other traits of importance is crucial.