Evaluation and selection of excellent lines after polycross of alfalfa

In the present study, the production performance and quality traits of 3 alfalfa cultivars (Gannong No.3, Gannong No.5 and Eureka) and their offspring after polycross were evaluated by two consecutive year sfield test. White flower 1# and Fast-growing 12# were the best lines with the hay yield of 16.45 and 14.02 t·ha-1, plant height of 100.40 and 102.37 cm, branch numbers of 26 and 27, growth rates of 1.61 and 1.70 cm per day, stem-leaf ratio of 0.98 and 0.96, crude protein of 23.15% and 21.25%, and relative feeding value of 154.72% and 145.23%, respectively. Fast-growing 11#, White flower 2# and Fast-growing 15# had higher plant height and better branching ability and Fast-growing 5# and White flower 3# had higher hay yield, smaller stem-leaf ratio and rich crude protein. The lines mentioned above were better which can be used for further alfalfa breeding after comprehensive evaluation.