Growth enhancement of the highly prized tropical trees siamese rosewood and burma padauk

Abstract

This study aims to evaluate the efficiency of the co-inoculation of arbuscular mycorrhizal fungi (AMF) and mycorrhizal helper bacteria (MHB) to promote the growth of siamese rosewood and burma padauk seedlings. The experiment was carried out in the pot experiment for 120 days. Three different species of AMF, Glomus clarum KKU−CLD−1, Clomus proliferum PC2−2 and Acaulospora mellea KKU−NBP−NB−2, were individually inoculated with and without the Stenotrophomonas maltophilia KKU−CLD−4.3−3−1. The results showed that the mycorrhizal helper bacteria strain S. maltophilia KKU−CLD−4.3−3−1 isolated from C. proliferum PC2−2 possessed high plant-growth promoting properties. The co-inoculation of our AMF species and MHB, especially in the treatment of C. proliferum PC2−2 and S. maltophilia KKU−CLD−4.3−3−1 could provide higher plant biomass, more nitrogen and phosphorus uptake and higher chlorophyll A, B contents compared to the non-inoculated control. The maximum growth of both types of seedlings was promoted by the treatment consisting of A. mellea KKU−NBP−SB−2, S. maltophilia KKU−CLD−4.3−3−1, and rock phosphate fertilizer. Co-inoculation of AMF and MHB could better promote plant growth parameters and improved phosphorus and nitrogen uptake in both types of seedlings than in the treatment with single inoculation. These suggested that our AMF and MHB were capable of being used as biofertilizer for the growth of Siamese rosewood and Burma padauk seedlings.