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 2019-2020 crop season at Dryland Agricultural Research Institute (DARI), Sararood, Kermanshah, Iran. A total of 251 safflower genotypes and two cultivars (Faraman and Sina) were planted in a non-repeating observational design. Total rainfall in Sararood station was equal to 518.8 mm, during the 2019-2020 cropping season. Regarding rainfall distribution, the amount of rainfall in autumn, winter and spring was 173.2, 229.1 and 116.5 mm (33.38%, 57.65% and 22.45% of the total annual rainfall), respectively. The results of this research showed genetic diversity in the studied germplasm. Mean seed yield, 1000- 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 879 kg/ha, 33 g, 30.4%, 268.1 kg/ha, 170 days, 200 days, 75.5 cm, 13.2 mm and 4.2, respectively. Genotypes PI198009, PI197831, PI271139 and PI305205 produced the highest seed yield (2427, 2483, 2693 and 2965 kg/ha, respectively) and the highest oil yield (675, 798, 804 and 937 kg/ha). The seed oil content of PI306971, PI306954, PI205604, PI306853 and PI343780 genotypes was above 35% 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, 1000- 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.