فهرست مطالب فاطمه محمدی آذر

In order to evaluate durum wheat lines in terms of frost stress tolerance, 45 promising durum wheat lines resulting from crosses between different parents were assessed using stress tolerance indices. This experiment consisting of greenhouse and laboratory tests was performed in the Faculty of Plant Breeding of MohagheghArdabili University in the 2017-18 crop year. In this experiment, wheat lines at seedling stage were studied. Durum wheat lines were planted in a factorial design based on randomized complete blocks with three replications. Plants up to 3 to 5 leaf stage were kept in greenhouse conditions. The pots were then taken to a cold room at 4°C to prepare for stress. Based on biological performance, tolerance indices (TOL), stress sensitivity (SI), average production (MP), stress tolerance index (STI) Geometric mean of production (GMP), Harmonic mean of production index (HARM), Yield reduction index (Yr) and Root and shoot tolerance index (TI) were calculated. The results of analysis of variance showed that the studied lines had significant differences in terms of MP, GMP and HARM traits and Yr and Ti indices were significant in stress. The interaction of the line in stress was insignificant for all indices. Due to the correlation between performance and indices, the most appropriate indices were MP, GMP, HARM and TOL. Comparison of mean lines and stresses were examined separately. The maximum correlation coefficient was related to the relationship (0.999) between STI index with SI, Yr with SI and Yr with STI. In general, GMP, MP and HARM indices are the most appropriate indices to evaluate the stress tolerance of lines at all levels. The study and TOL index were suitable for higher stress levels. Study of lines by indices using cluster analysis, detection function analysis and factor analysis showed similar results. The results of cluster analysis and factor analysis with the first three factors introduce lines 25, 26, 27, 28, 31, 36 and 39 as the most tolerant lines and lines 11, 13, 15, 17, 18 and 19 as the most sensitive. They were identified. In factor analysis, the first three factors explained 97.52% of the available variance and the indices of STI, SI, Yr, Ti aerial parts, MP, GMP and HARM They had the highest value and were the most effective indicators in the distribution of lines. According to the three-dimensional diagram of line distribution, the highest factor coefficients based on the first three factors were related to lines 5, 7, 25, 26, 27, 28, 31, 36 and 39.

Cold tolerance in wheat is one of the most important factors effective in the field of winter damage in Iran. Freezing and laboratory tests were carried out in the greenhouse and plant breeding laboratory of Mohaghegh Ardabili University in 2018-20 to achieve the set goals. The plant materials used included 45 promising durum wheat lines. Durum wheat genotypes were planted in a randomized complete block design with three stress levels. The results of the variance analysis of LT50 showed a significant difference between the genotypes at the probability level of 1%. LT50 varied between -0.754 and -26.609 values. The survival percentage of plants decreased with increasing stress. In clustering based on the LT50, the genotypes were divided into 5 groups. The dendrogram obtained from the cluster analysis based on all the traits divided lines in the control level, -8 °C, -10 °C, and -12 °C into 8, 6, 9 and 7 different groups. Four factors were identified in the control level, 5 in the first stress, 6 in the second stress, and 5 in the third stress level. To evaluate the relationship between the measured traits and RAPD molecular markers, stepwise multiple regression analysis was performed and significant relationships were observed. LT50 showed a correlation with 9 markers. Finally, according to the tests conducted, lines 1, 2, 3, 4, 5, 6, 7, 8, 10, and 23 were recognized sensitive lines and lines 11, 12, 13, 14, 15, 17, 18, 19, 21, 29, 31 and 27 were recognized as resistant.