The nitrogen-fixing Frankia significantly increases growth, uprooting resistance and root tensile strength of Alnus formosana

Abstract

Restoration of Alnus formosana (Burk.) Makino on landslide areas is important for agroforestry, forestry and soil erosion control in Taiwan. To ensure successful reforestation, A. formosana seedlings have to develop strong root system for nutrient and water acquisition as well as anchorage. Inoculating of A. formosana with symbiotic nitrogen-fixing actinobacteria Frankia may help mitigate drought and nutrient deficiencies on landslide sites. However, the effects of Frankia inoculation on growth, root architecture and mechanical properties of A. formosana seedlings are not well understood. In this research, a Frankia strain AF1 was isolated from actinorhizal nodules of local A. formosana and recognized as Frankia species, and its influences on growth performance and root mechanical properties of A. formosana seedlings were examined and analyzed. The results showed that the inoculated seedlings had significantly larger height and root biomass, longer root length, and more root tip number than that of the non-inoculated controls. Consistently, the inoculated seedlings had statistically significant higher uprooting resistance, root tensile resistance force and tensile strength than the controls. The results reveal that this native Frankia strain can promote growth performance, root system architecture, anchorage ability and root tensile strength of A. formosana.

Effects of different straw biochar combined with microbial inoculants on soil environment in pot experiment

“…They are important nitrogen suppliers in terrestrial ecosystems, so they have a wide application prospect in agriculture and forestry. Thus, Frankia has the potential to be used in nature as a powerful resource 25 . Other studies have found that Frankia , like other actinomycetes, can produce antimicrobial substances that inhibit the growth of microorganisms, such as Escherichia coli , Staphylococcus aureus , Candida albicans , and Penicillium chrysogenum 26 .…”