Abstract: An experiment with LED light source irradiation of 4 ratios (0.5, 2.5, 4.5, and 6.5) of red light (R: 660±10 nm) to far-red light (FR: 730±10 nm) was conducted to study the effects of red/far red light ratio (R/FR) on the flower bud differentiation, relative growth rate, and inflorescence diameter of Chrysanthemum morifolium cv. ‘Jingba’. In treatment R/FR=6.5, the duration needed by the ‘Jingba’ to complete its flower bud differentiation was the shortest, being shortened by 34 days as compared to treatment R/FR=0.5. The larger the R/FR, the higher the relative growth rate for the flower bud differentiation would be. When the flower bud differentiation completed, the relative growth rate in treatment R/FR=6.5 was as twice as that in treatment R/FR=0.5. Similar to the flower bud differentiation, the dimension of inflorescence diameter was in the order of treatment R/FR 6.5 > R/FR 4.5 > R/FR 2.5 > R/FR 0.5. This study indicated that the R/FR ratio of 6.5 could promote the chrysanthemum flower bud differentiation and the inflorescence diameter growth significantly.

Key words: ecological network, gravity model, biodiversity., least cost model