Characterization of tetraploid wheat landraces for cold tolerance and agronomic traits under rainfed conditions of Iran

Abstract

Abiotic stresses such as cold and drought are major limiting factors of durum wheat production in the highlands of Iran. A total of 641 tetraploid wheat (Triticum turgidum L.) accessions, selected from wheat collections conserved at ICARDA gene-bank, were evaluated under rainfed conditions at three highland research stations in cold and moderately cold areas of Iran. The main objectives were to (i) compare the different tetraploid wheats for cold tolerance and agronomic performance in relation to their growth habit (spring, facultative and winter) and (ii) examine the potential of accessions to combine cold and drought tolerance with high yield and good agronomic traits, for their further use in durum wheat breeding. Plant height, thousand-kernel weight and grain yield were the traits that best differentiated the accessions. The winter types had better agronomic performance, higher chlorophyll content (SPAD) and cold tolerance, compared to facultative and spring types. Most of the cold-tolerant accessions belonged to T. turgidum subsp. durum and T. turgidum subsp. carthalicum. Some of the accessions combined high yield with the level of cold and drought tolerance that is needed for the development of cultivars adapted to the highlands of Iran. The results indicated that related species could be used to improve winter hardness and cold tolerance in durum wheat and selection for earliness, high chlorophyll content and grain yield may lead to better cold tolerance and adaptation to the highland areas of Iran.