Co-cultivation of cyanobacteria for raising nursery of chrysanthemum using a hydroponic system

The present investigation aimed to utilize plant growth–promoting diazotrophic cyanobacteria as an option to raise the chrysanthemum varieties Pusa Aditya and Jaya in a nursery by co-culturing hydroponically. Fresh stem cuttings of chrysanthemum were planted in BG 11 medium (−N) which was inoculated to log-phase cultures of Anabaena torulosa (BF1), Anabaena doliolum (BF4), and Anabaena laxa (RPAN8) individually. Analyses of chrysanthemum growth and biometric/biochemical parameters after 30 days of co-cultivation revealed that co-culturing treatments performed significantly better, as compared with BG11 medium alone. Anabaena laxa brought about an increment of 27–40% in IAA production in the root tissues of both varieties grown in hydroponics . Quantification of biofilm formation on roots (measured as OD 550 ) illustrated a two- to four-fold increment in the co-culture treatments. PEP carboxylase activity was significantly enhanced in root and shoot tissues of cuttings in Jaya , and the medium chlorophyll enhanced by several folds in both varieties. Significant increases in root dry biomass were recorded, which positively correlated with root protein ( r = 0.992) in Pusa Aditya , illustrating the superiority of co-culturing as a promising option for nursery propagation. The economic benefits of BG 11 medium (without combined N) as a novel growth medium for growing the cyanobacterium and raising chrysanthemum nursery, in co-culturing mode, were also highlighted. Anabaena torulosa (BF1) performed well in both Pusa Aditya and Jaya , while Anabaena laxa (RPAN8) was significantly superior in Jaya . Future research is focused towards integration of such novel and cheap organic inputs in maintaining disease-free and nutrient-enriched plants in long-term experiments up to flowering stage. Graphical abstract National PhytotronFacility PusaAditya.