Effect of pH and citric acid on the growth, arsenic accumulation, and phytochelatin synthesis in Eupatorium cannabinum L., a promising plant for phytostabilization.

Heavy-metal contamination of soils has increased in the last decades due to anthropogenic and industrial activities. Arsenic is one of the pollutants that is commonly found in industrial soils and is toxic for both plants and humans. The pH of the soil or the culture medium is one of the most important factors that interferes with the bioavailability of this metalloid to the plant.

Gemmation in cultured gametophytes ofOsmunda regalis.

Gametophytes ofOsmunda regalis were culturedin vitro to determine the optimal conditions for growth and development. Culture media with low ammonium concentration (Knop, Knudson or 1/4 Murashige and Skoog dilution) were the most effective for growth of this organism. Addition of sucrose and mannitol to the culture medium at the same osmoticum, inhibits or enhances, respectively, growth and development of the gametophytes, which show a strong autotrophyin vitro.