The potential of arbuscular mycorrhizal fungi to conserve Kalappia celebica, an endangered endemic legume on gold mine tailings in Sulawesi, Indonesia

Kalapi (Kalappia celebica) is an endemic legume of Sulawesi and has been included in the endangered category since the early 1980s. Conservation of the species is possible through ex situ culture techniques. Arbuscular mycorrhizal fungi (AMF) can accelerate plant growth which in turn supports the conservation of endangered species. This study aimed to assess the efficacy of local AMF to accelerate the growth of kalapi and increase nutrient uptake in kalapi grown in gold mine tailing media. There were three AMF treatments, Glomus claroideum, Glomus coronatum, and a mixture of both, plus the control. Each treatment was replicated three times, each consisting of five plants. The results show that the highest AMF colony was obtained by kalapi seedlings inoculated with Glomus coronatum and the mixture of AMF. The range of mycorrhizae inoculation effect values was 59.7-71.3%. AMF inoculation increased growth and dry weight of 4-month-old seedlings compared to controls. Dry and total weights of kalapi inoculated with G. coronatum were significantly different from those inoculated with the AMF mixture. However, they are not significantly different from kalapi inoculated with G. claroideum. The results also show that AMF increased nitrogen and phosphorous uptake by the roots, as well as nitrogen, phosphorous, potassium, manganese and iron by the shoots. All AMF treatments decreased potassium uptake in the roots, except in kalapi inoculated with G. coronatum. The AMF mixture decreased iron contents the roots by 15%. AMF can be developed into biofertilizer to support the conservation of kalapi in tropical Indonesia.

Automated summary

The study demonstrated that local arbuscular mycorrhizal fungi (AMF) can significantly accelerate the growth of Kalapi and increase nutrient uptake, especially with Glomus coronatum and a mixture of AMF showing the most significant effects.