Abstract
Microalgae have been identified to produce a plethora of bioactive compounds exerting growth stimulating effects on plants. The objective of this study was to investigate the plant-growth-promoting effects of three selected strains of eukaryotic green microalgae. The biostimulatory effects of two Chlorella species (MACC-360 and MACC-38) and a Chlamydomonas reinhardtii strain (cc124) were investigated in a Medicago truncatula model plant grown under controlled greenhouse conditions. The physiological responses of the M. truncatula A17 ecotype to algal biomass addition were characterized thoroughly. The plants were cultivated in pots containing a mixture of vermiculite and soil (1:3) layered with clay at the bottom. The application of live algae cells using the soil drench method significantly increased the plants’ shoot length, leaf size, fresh weight, number of flowers and pigment content. For most of the parameters analyzed, the effects of treatment proved to be specific for the applied algae strains. Overall, Chlorella application led to more robust plants with increased fresh biomass, bigger leaves and more flowers/pods compared to the control and Chlamydomonas-treated samples receiving identical total nutrients.
Highlights
The human population has significantly increased over the past few decades
This result could be attributed to changes in the HDL1 gene, which plays a role in the maintenance of shoot apical meristems (SAM) and leaf blade length determination
HDL1 was found to participate in auxin-dependent leaf morphogenesis [74] which implies that the C. reinhardtii cc124 treatment had an influence on auxin homeostasis in plants
Summary
The human population has significantly increased over the past few decades. This increase has raised the demand for food but reduced land for crop production because of urbanization and clearance for human settlement. Chemical fertilizers have been used for various crops including forage and food crops. Chemical fertilizers have detrimental effects on the environment as they cause accumulation of nitrogen and phosphorous to harmful levels. The accumulated nutrients alter the balance in most ecosystems and reduce biodiversity. Chemical fertilizers no longer have a significant impact on crop yield unless when used at high concentrations, which is not economical for farmers
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
