Isolation of Endophytic Bacteria from Palaquium Maingayi and Their Ability to Promote Plant Growth

Abstract

Mutual interaction between endophytic bacteria and their plant host benefits both sides in a sustainable environment. To date, various endophytic bacteria with plant growth-promoting potential have been reported from a wide variety of plants. The present study aims to isolate endophytic bacteria with plant growth-promoting characteristics and potentially become biofertilizers to promote plant growth. These endophytic bacteria were isolated from the roots of Palaquium maingayi inhabiting Universiti Putra Malaysia Campus Bintulu (UPMKB) Borneo Base Forest. In total, 66 endophytic bacteria were isolated and examined for their phosphate solubilization, indole-3-acetic acid (IAA) production, siderophore production and antagonistic characteristics against pathogenic fungi and bacteria. Out of 66 endophytic bacterial isolates, 11 were able to solubilize phosphate, produce IAA and siderophore, and promote plant growth. 6 endophytic bacteria isolates were found to have antagonistic activities against Ganoderma borneensis, Fusarium solani and Ralstonia solanacearum. The results of plant inoculation showed that these bacteria strains significantly promote root and shoot biomass on maize plants compared to uninoculated plants. To our knowledge, this is the first report on isolating endophytic bacterial strains from the Palaquium Maingayi tree with plant growth-promoting potential. The success of isolation and identification of endophytic bacteria from selected trees in the UPMKB Borneo base forest can potentially produce bio-fertilizers to promote plant growth for sustainable agriculture.