The impact of PEG-induced drought stress on early vigour traits of bread wheat

A total of 11 genotypes from the collection of 101 bread wheat genotypes, with desirable traits in terms of increased tolerance to drought, were chosen for parents and eight crosses were performed. Number of seminal roots (NSR), total root length (TRL), root dry mass (RDM), number of shoots per plant (NS), main shoot length (MSL), shoot dry mass (SDM), number of leaves per plant (NL), leaf area per plant (LA), leaf dry mass (LDM), aboveground dry mass (ADM), SDM/LDM, RDM/ADM were analysed at the boot stage (Z45). The F1 progeny had on average higher mean values (P < 0.001) than parents for four traits: RDM, NS, LA and RDM/ADM. The highest broad sense heritability values were determined for RDM (97.6%) and NSR (93.9%). Factor analysis indicated that a large root system, higher RDM and TRL are associated with higher NS, NL, LA and LDM. For Euclid x CHI-4 and WWBMC2 x Ingenio combinations the highest heterosis values were observed for TRL (34.1%) and SDM (23.7%), for RDM (28.6%) and LA (26.8%), respectively. PEG-induced drought stress in the seedling stage, in most of the new germplasm, caused an increased redistribution of dry matter in the root compared to the stem.