Phenotypic Variability, Heritability and Associations of Agronomic and Quality Traits in Cultivated Ethiopian Durum Wheat (Triticum turgidum L. ssp. Durum, Desf.)

Abstract

Quality is an important aspect of durum wheat in the processing sector. Thus, recognizing the variability of quality and agronomic traits and their association is fundamental in designing plant breeding programs. This study aimed to assess the variability, heritability, genetic advance, and correlation of some agronomic and quality traits among 420 Ethiopian durum wheat genotypes and to identify the promising genotypes with distinct processing quality attributes to produce superior quality pasta. The field experiment was conducted at two locations (Sinana and Chefe Donsa) using an alpha lattice design with two replications. Analysis of variance, chi-square test, and Shannon–Weaver diversity index revealed the existence of highly significant (p < 0.001) variation among genotypes for all studied traits. The broad-sense heritability values were ranging from 46.2% (days to maturity) to 81% (thousand kernel weight) with the genetic advance as a percent of the mean ranging from 1.1% (days to maturity) to 21.2% (grain yield). The phenotypic correlation coefficients for all possible pairs of quantitative traits showed a significant (p < 0.05) association among most paired traits. The gluten content (GC) and grain protein content (GPC) were negatively correlated with grain yield and yield-related traits and positively associated with phenological traits, while yield and phenological traits correlated negatively. The frequency distributions of amber-colored and vitreous kernels, which are preferable characters of durum wheat in processing, were highly dominant in Ethiopian durum wheat genotypes. The identified top 5% genotypes, which have amber color and vitreous kernel with high GC and GPC content as well as sufficient grain yield, could be directly used by the processing sector and/or as donors of alleles in durum wheat breeding programs.

Genetic Diversity of Durum Wheat (Triticum turgidum L. ssp. durum, Desf) Germplasm as Revealed by Morphological and SSR Markers

“…The PCA divided the genotypes into three groups based on the magnitude and direction of the contribution of different traits to the principal components (Figure 2). The positive contribution of GC and GPC, and the negative contribution of SPD and SPS to both principal components (PC1 and PC2), suggest the negative correlations of GC and GPC with SPD and SPS in durum wheat, as noticed by Dagnaw et al [9]. Similar grouping patterns of morphological traits in a PCA biplot were also observed in previous research [68][69][70].…”

“…The investigated SSR loci showed significant associations with one or more target phenotypic traits. The SSR Xgwm46 showed a significant association with GPC and GY ( Figure 7 ), which are highly correlated traits [ 9 ]. This SSR was previously reported to be associated with GPC [ 39 ] and GY [ 36 ].…”

“…In this study, 104 genotypes of Ethiopian durum wheat were used, which included 94 landraces and 10 cultivars selected from those used in the study by Dagnaw et al [ 9 ] on the basis of their grain quality and yield. The landraces representing different geographical regions were obtained from the Ethiopian Biodiversity Institute (EBI) ( Figure 1 ) and characterized for two consecutive years (2017–2018) at Sinana Agricultural Research Center (SARC) to maintain their trueness to type for further characterization.…”

“…Ethiopia is one of the main centers of durum wheat genetic diversity [ 5 , 6 , 7 , 8 , 9 ]. However, landraces have been neglected for over five decades, and their production has declined from 60% of total production in the 1970s to 10–15% in 2018.…”

Mapping QTL for Yield and Its Component Traits Using Wheat (Triticum aestivum L.) RIL Mapping Population from TAM 113 × Gallagher

“…Grain yield (YLD) can be dissected into three components, including spike m −2 (SPM), kernels spike −1 (KPS), and thousand kernel weight (TKW) [4,5]. Grain yield is a quantitative trait significantly influenced by environmental factors and genotype-by-environment interactions [6], but genetic factors remain the stable components controlling yield [7], indicating a greater potential for improving the trait genetically [8][9][10]. Under adverse environmental conditions, the heritability of overall yield may be low [11][12][13], but for traits of yield components such as TKW, SPM, KPS, kernel length (KLEN), kernel width (KWID), and kernel perimeter (KPERI), moderate to high heritability were reported [14,15].…”