Genetic variation for winter survival and related characteristics in barley genotypes

An investigation was carried out in order to study the genetic variation of barley genotypes in terms of winter survival, LT50 and leaf soluble carbohydrates under field and greenhouse conditions using 40 barley genotypes in the research station and greenhouse of Faculty of Agriculture, University of Tabriz, Iran. The field evaluation was performed in the form of randomized complete block design in two years and percentage of winter survival was estimated. Multivariate analysis of variance indicated significant differences among genotypes for the traits measured in greenhouse and laboratory. Combined analysis of variance showed significant differences among genotypes for percentage of winter survival, but the effects of year and genotype × year interaction were significant for this character. The greenhouse experiment for percentage of plant survival was carried out in the form of split plot design on the basis of randomized complete blocks with two replications. Barley genotypes were assigned in subplots and five freezing temperatures (-8, -11, -13, -15 and -17°C) were assigned in main plots. Other traits measured in the greenhouse, such as LT50, percentage of seedling dry weight, soluble carbohydrates content before and after hardening and leaf length and width were analyzes based on randomized complete block design. Significant differences were observed among barley genotypes in terms of survival percentage at temperatures -8, -11, -13, -15 and -17°C, LT50, percentage of seedlings dry weight, leaf width and the soluble carbohydrates content after hardening. The heritability of field survival percentage, LT50 and leaf width were high. The heritability of soluble carbohydrates content after hardening and the percentage of seedling dry weight were moderate. The highest and lowest heritability were observed at temperatures -8°C and -17°C, respectively. Percentage of survival at temperature -15°C had the largest squared genetic coefficient of variation and other traits had low squared genetic coefficient of variation. It can be concluded that genotype #38 (Athenise) was susceptible to cold stress and considerable number of genotypes had desirable characteristics for cold tolerance from which genotypes #36 (Schulyer) and #15 (EC83-12) can be recognized as more cold tolerant genotypes with regard to percentage of winter survival and LT50.