The potential of the new synthetic variety of Iranian sainfoin (Onobrychis viciifolia Scop.)

Sainfoin (Onobrychis viciifolia Scop.) is a perennial forage legume, widely distributed in the northern temperate region and has received renewed interest in the world. This experiment was carried out to proceed from the previously-produced Syn1 generation of a new synthetic variety to the Syn2 generation. The Syn2 generation was produced and evaluated during the 2015-2019 growing seasons. In the first two years, the seeds of the Syn2 generation and composite varieties were produced in completely isolated condition. Then, the Syn2 generation along with the Composite, Sarab, and Bostan-Abad varieties were evaluated in the field conditions for three years (2017-2019). Significant differences were observed for the fresh and dry matter yield and plant height among the studied sainfoin varieties. The Synthetic variety showed the highest annual fresh forage yield (36785 kg ha-1) which was significantly different from other varieties. A similar result was obtained for the annual total dry matter yield, and the Synthetic variety showed the highest dry matter yield (11715 kg ha-1). The superiority of the Synthetic variety over the average of the ecotypes of Sarab and Bostan-Abad was about 25% for the dry matter and fresh forage yield. The plant height of the Synthetic variety was 83 cm, which was higher than other varieties. Among the studied varieties, no significant differences were observed for the traits related to forage quality. The protein content, total ash, crude fiber, water-soluble carbohydrates, and acid detergent fiber in the Synthetic variety were 18.52, 7.40, 19.95, 44.70, and 19.6%, respectively. The results indicated