Research Article Variation and Relationships among Agronomic Traits in Durum Wheat [Triticum turgidum (L.) Thell. ssp. turgidum conv. durum (Desf.) MacKey] under South Mediterranean Growth Conditions: Stepwise and Path Analyses AliMansouri , 1 BachirOudjehih, 1 AbdelkaderBenbelkacem, 2 ZineElAbidineFellahi , 3 and Hamenna Bouzerzour 4 1 Agronomy Department, El Hadj Lakhdar University, 5000 Batna, Algeria 2 Plant Breeding and Biotechnology Division, National Agronomic Research Institute of Algeria (INRAA), 25000 Constantine, Algeria 3 Department of Agronomy, Faculty of Natural, Life and Earth Sciences and the Universe, University of Mohamed El Bachir El Ibrahimi, 34030 Bordj Bou Arreridj, Algeria 4 Valorization of Natural Biological Resources Laboratory, University of Setif, 19000 Setif, Algeria Correspondence should be addressed to Ali Mansouri; aliwheat@yahoo.fr Received 28 December 2017; Accepted 7 May 2018; Published 25 June 2018 Academic Editor: Maria Serrano Copyright © 2018 Ali Mansouri et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Relationships among agronomic traits and grain yield were investigated in 56 genotypes of durum wheat (Triticum durum Desf.). e results indicated the presence of sufficient variability nearly for all measured traits. Heritability and expected genetic gain varied among traits. Aboveground biomass, harvest index, and spike number were the most grain yield-influencing traits. Early genotypes showed above-average grain and biological yields, spike number, and lower canopy temperature. Assessed genotypes were clustered into three groups which differed mainly for biological, economical, straw, and grain yields, on the one hand, and plant height, chlorophyll content, and canopy temperature, on the other hand. Selection for direct use from clusters carrying best combinations of yield-related traits and crosses to be made between genotypes belonging to contrasted clusters were suggested to generate more variability. Selection preferentially for spike number, biological yield, harvest index, and canopy temperature to accumulate favorable alleles in the selected entries for future uses is suggested. 1. Introduction Durum wheat (Triticum turgidum L. var. durum) is grown on around 17 million hectares worldwide, representing 8% of the world’s wheat area [1]. It is among the most cultivated crops in the Mediterranean basin, where approximately 75% of the world’s durum wheat area is still grown, which contributes to 50% of the worldwide production [2]. In the Mediterranean basin (characterized by highly variable en- vironments), wheat is mainly grown under rainfed condi- tions, and yield is often constrained by water and heat stresses that are common during the grain-filling period, which is due to the low and unpredictable seasonal rainfalls and high temperatures during the last stages of its devel- opment cycle [3]. Terminal drought and heat stresses neg- atively affect wheat grain weight and yield [4, 5]. Breeders, all over the world, are traying through wheat breeding programs to develop productive and adapted cultivars to their specific environments. is was resulted in the release of several commercial varieties. However, obtaining high-yielding genotypes of durum wheat, espe- cially for Mediterranean rainfed areas, is considered difficult due to high genotype × environment interaction [6, 7]. In Mediterranean rainfed areas, genetic improvement of Hindawi International Journal of Agronomy Volume 2018, Article ID 8191749, 11 pages https://doi.org/10.1155/2018/8191749