Cyanobacterial amendment boosts plant growth and flower quality in Chrysanthemum through improved nutrient availability

Abstract

Cultivation of ornamentals requires heavy inputs of chemicals, which can be provided in an environment-friendly manner through cyanobacterial inoculation, facilitating better availability of key macro/micronutrients from the surrounding environment to the host plant and stimulate plant growth. Therefore, the objective of the present investigation was to compare a nursery of Chrysanthemum variety Pusa Aditya grown using potting medium amended with a diazotrophic cyanobacterial strain Anabaena torulosa, with the routine nursery potting medium, for their potential towards improving flower traits, soil fertility and crop productivity. In order to demonstrate the nitrogen savings, the plantlets from such primed nurseries were transplanted into pots, receiving two different doses of nitrogenous fertilizer (full N and 75% N), along with full doses of recommended P and K fertilizers. An increment of 1.8-fold in terms of nitrogen availability in soil was recorded in treatments receiving 75% N along with full doses of recommended P and K fertilizers and cyanobacterium-primed nursery, as compared to all other treatments. An average increase of 35% in the fresh weight of flowers, flower pigmentation as well as early appearance of flower buds was recorded. A significant stimulation of antioxidant and defense enzyme activities in plants, due to cyanobacterium amendment at nursery stage was also recorded. Correlation analyses illustrated a positive association of soil biological attributes (root biofilm formation, soil polysaccharides, glomalin related soil proteins) with most parameters related to plant growth, particularly, reproductive development and flower quality aspects. Principal component analysis illustrated the greater association of these parameters with the treatments involving Anabaena torulosa amended nurseries. It can be concluded that cyanobacterium-amended nurseries can be a useful intervention for deriving robust planting units and leading to beneficial influences on soil nutrient availability, flower quality traits and yield.