Abstract:

To evaluate the freezing resistance and genetic diversity in barley physiological traits, molecular markers and their relationship in 20 barley genotypes were assessed in field and greenhouse condition. The analysis of variance showed a significant difference among studied genotypes. The effect of acclimation temperature on prolin content, quantum efficiency of photosystem II, chlorophyll and soluble sugars content were studied as physiological traits. Freezing treatments were -4, -7, -10, -13 and -16°C temperatures that applied in a 3 replicated randomized complete block design. Then their lethal temperature at which 50% of plant were died (LT50) was determined. To estimate FSI (Field Survival Index) index, the 20 genotypes were cultured in a separate experiment on field with 3 replications. The results showed negative significant correlation (-0.601) between field survival index and LT50. Cluster analysis using physiological traits, genotypes of F-A1-1, F-A1-2, F-A2-11, F-GRB-85-5, Sahra, Sahand, Dasht and Makouei were categorized in a distinct group and had a high FSI and low LT50. Makouei cultivar having LT50=-17.66°C and the highest percentage of winter survival in the field, was the most resistant genotype. 10 ISSR markers from 35 primers sequences were selected and used. These 9 ISSR primers produced 50 polymorphic bands. PIC and MI average index for all primers were 0.37 and 1.72 respectively. Cluster analysis of molecular data using Jaccard similarity coefficient categorized the genotypes to four distinct groups. Associations between molecular markers and traits were assessed by multiple regression analysis. Some informative markers related to FSI and also LT50 was determined. So it may be possible to use these markers for selection of resistant lines or genotypes in breeding programs.

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