Effect of Microalgal Extracts from Chlorella vulgaris and Scenedesmus quadricauda on Germination of Beta vulgaris Seeds

Sugar beet (Beta vulgarissubsp.vulgaris) is a commercially important biennial root crop, providing about 20% of the world's annual sugar production. Seed quality is crucial for adequate plant growth and production. The productivity of sugar beet is often limited by heterogeneous germination in the field. In order to improve the sugar beet germination process, the effect of different concentrations of microalgal extracts fromChlorella vulgarisorScenedesmus quadricaudawas investigated by calculating several indices useful to evaluate the germination performance. Moreover, root morphological analysis was performed by using WinRHIZO software.B. vulgarisseeds were soaked with five different concentrations (from 0.1 to 10 mg C-org/L) of the microalgal extracts, considering the amount of organic carbon (C-org) in each extract. Our results show that these microalgal extracts exert a positive effect on sugar beet germination, by increasing efficiency and regularity of this critical process forB. vulgarisseeds. The best results, in terms of germination indices as well as root morphological traits, were reached by usingC. vulgarisextract at the concentrations C2 (1 mg C-org/L) and C3 (2 mg C-org/L).