Carnivorous plants typically grow in low-nutrient environments. As many of their habitats are vanishing and interest in this group of plants is increasing, culturing carnivorous plants is becoming more relevant. Yet their preference for low-nutrient habitats makes carnivorous plants challenging to rear. Utricularia, the largest genus among carnivorous plants, are of particular interest due to their wide distribution, relatively fast growth rates among carnivorous plants, their extremely small genome, and their energetically expensive active traps.
Utricularia must invest resources in traps carefully not only because carnivory comes at an expense of photosynthetically active biomass, but because active traps continue exact considerable energetic costs. The exact rules that govern this partitioning of resources in bladderwort is still unknown.
The gold-standard media for culturing Utricularia is still sphagnum peat-moss and distilled water. However, peat-based media are chemically complex, making it difficult to control parameters such as pH, osmotic pressure, and relative mineral-ion content for essential such studies.
Here we use the aquatic bladderwort U. australis to create a synthetic inorganic equivalent of a peat-water extract to understand how a change in NPK ratio affects the plant’s relative gain in biomass and investment in carnivory.
Results/Conclusions
Our experiment uses a 3-factor Response Surface Methodology (RSM) design to generate plant response curves based on inputs of increase in strand length, bladder count, and bladder size 2-weeks after being placed in a prey-deprived inorganic media with varying ratios of N, P & K.
A synthetic inorganic media based solely on the major nutrients N, P & K, Fe and Mg at concentrations imitated from a peat-water extract failed to achieve appreciable growth compared with a peat-water extract. A follow up experiment using solutions of 1/2 strength Gamborg B5 media salts showed growth rates comparable to a peat-water extract. Optimization of the N, P & K ratios using this pilot as a baseline promises a deeper understanding of the interrelation of these mineral nutrients in the bladderwort physiology, and the ability to culture these plants in a lab environment with predictable growth patterns.