Maternal environment and genetic mechanisms that regulate primary dormancy and the rate of dormancy loss in barley seeds

Abstract

ABSTRACT Pre-harvest sprouting is a concern in malting barley (Hordeum vulgare L.) in areas with a high amount of rainfall, as it decreases grain yield and malt quality. Thus, we investigated the changes in initial germination and the rate of dormancy loss in seeds of 20 promising barley genotypes at seven locations for two years (2013–2015) in Iran. Initial germination ranged between 5.23% (genotype “Teran 78/1-BC-80,411”) and 38.45% (genotype “CIRU/M111”) at the maturity. In several genotypes, there were negative associations between initial germination and the average temperature in March, April and May. The rate of dormancy loss and precipitation were negatively correlated in 14 genotypes in March. Thus, a hot and dry condition during seed development can decrease initial germination but can increase the rate of dormancy loss in barley. A genotype with high initial germination is suitable for cultivation in regions with a dry climate during grain development, and a genotype with a high rate of dormancy loss is appropriate in a climate with high rainfall and relative humidity. In conclusion, breeding programs must link dormancy intensity of target barley and environmental conditions (air temperature and humidity) that the crop will experience.