Investigation of changes in agronomic traits in collection accessions of bread wheat under salinity stress

Soil salinity and poor irrigation water quality are a global problem in crop production. Thedevelopment of tolerant cultivars is one of the most important solutions to overcome theproblem of salinity, but it requires access to and identification of genetic resources withgenetic diversity for this trait. In order to identify germplasm tolerant to salinity stress andeffective traits, 413 accessions from the bread wheat collection of the National Plant GeneBank of Iran were cultivated in the 2012-2013 crop year in saline lands of ArdakanResearch Station and also under normal condition in Karaj research filed in Augmentedstatistical design and evaluated by measuring agronomic traits. Based on the results ofdescriptive statistics under salinity stress, spike density (20.27%) and five-spike grainweight (19.99%) were the highest and days to spike (7.90%) and days to full maturity(4.90%) had the lowest coefficient of variation. The highest mean decrease in theevaluated traits under salinity stress compared to normal condition belonged to the grainweight of five spikes (31.02%) and 100-grain weight (21.82%). Under salinity stress,accessions of KC 11791 (5.6 g) and KC 11622 (5.4 g) had highest value of 100 grainweight, and accessions KC 11946 (9.0 g) and KC 11816 (8.78 g) possessed highest valueof grain weight of five spikes. Under salinity stress, the first four principal componentsaccounted for 77.76% of the data variation. The studied genetic materials weredifferentiated into five groups using K means cluster analysis. The results of the presentstudy led to the identification of a large number of wheat bread tolerant to salinity stresswith a range of diversity in the evaluated traits that can be used as diverse raw materials inbreeding programs