Assessment of Genetic Diversity Based on Agronomic Traits in Safflower International Germplasm under Rainfed Condition of Cold Temperate Region in Iran

To study the genetic diversity based on agronomic traits and their application in safflower breeding programs, an experiment was conducted in the ۲۰۱۹-۲۰۲۰ crop season at Dryland Agricultural Research Institute (DARI), Sararood, Kermanshah, Iran. A total of ۲۵۱ safflower genotypes and two cultivars (Faraman and Sina) were planted in a non-repeating observational design. Total rainfall in Sararood station was equal to ۵۱۸.۸ mm, during the ۲۰۱۹-۲۰۲۰ cropping season. Regarding rainfall distribution, the amount of rainfall in autumn, winter and spring was ۱۷۳.۲, ۲۲۹.۱ and ۱۱۶.۵ mm (۳۳.۳۸%, ۵۷.۶۵% and ۲۲.۴۵% of the total annual rainfall), respectively. The results of this research showed genetic diversity in the studied germplasm. Mean seed yield, ۱۰۰۰- seed weight, seed oil content, seed yield, flowering period length, physiological ripening period, plant height, pod diameter and the number of sub-branches per plant for the genotypes were ۸۷۹ kg/ha, ۳۳ g, ۳۰.۴%, ۲۶۸.۱ kg/ha, ۱۷۰ days, ۲۰۰ days, ۷۵.۵ cm, ۱۳.۲ mm and ۴.۲, respectively. Genotypes PI۱۹۸۰۰۹, PI۱۹۷۸۳۱, PI۲۷۱۱۳۹ and PI۳۰۵۲۰۵ produced the highest seed yield (۲۴۲۷, ۲۴۸۳, ۲۶۹۳ and ۲۹۶۵ kg/ha, respectively) and the highest oil yield (۶۷۵, ۷۹۸, ۸۰۴ and ۹۳۷ kg/ha). The seed oil content of PI۳۰۶۹۷۱, PI۳۰۶۹۵۴, PI۲۰۵۶۰۴, PI۳۰۶۸۵۳ and PI۳۴۳۷۸۰ genotypes was above ۳۵% and higher than other genotypes. Considerable diversity in the morphological characteristics of the germplasm was observed in this research, which indicates the possibility of using them in breeding programs. Finally, some genotypes were selected that seed yield, ۱۰۰۰- seed weight, seed oil content, plant height, pod diameter and the number of sub-branches per plant were more than the third quarter and the number of days from planting to flowering and their physiological maturity were less than the first quarter. These genotypes were chosen for repeated experiments in the following year.