Identification of superior spring durum wheat genotypes under irrigated and rain-fed conditions

An important objective of wheat improvement programmes is to breed varieties for high yield in optimum conditions and for minimum yield reduction under stress-prone conditions such as heat and drought. Analyses of yield and its components in multiple years allow a comprehensive and comparative understanding of genetic yield potential and stress-tolerance mechanisms in the study germplasm. The present study was carried out to evaluate performance of elite varieties and landraces of spring durum wheat under different water regimes, determine the repeatability of the examined traits, and identify superior genotypes for their potential use in breeding for drought tolerance. A total of 97 accessions of spring durum wheat (T. durum Desf.) were evaluated under rain-fed and well-watered conditions in the nursery of the Centre for Agricultural Research at Martonvasar, Hungary (2011-2013). The experiments were laid out in an unbalanced, incomplete alpha lattice block design. The trait with the lowest broad-sense repeatability was seed length (0.075), while high h(2) values were observed for heading date (0.89), thousand-grain weight (0.85) and the protein content (0.85). Grain yield showed moderate level of repeatability (0.53) across the three years. The principal component analysis revealed that grain yield (t/ha) is positively associated with the fertile tiller number, chlorophyll content values at early waxy ripeness stages and plant height. Based on biplot analysis, 'DP-133 ', 'DP-017 ' and 'DP-061 ' proved to be the best durum cultivars in terms of yield whereas genotypes 'DP-011 ', 'DP-185 ', 'DP-126 ' and 'DP-136 ' preceded them with their good yield stability.