Healthy leaf, shoot and root tissues of Eaglewood (Aquilaria crassna Pierre ex Lec.) were collected from the plantations in Nakhonnayok province (14° 7′ 20.60″ N, 101° 4′ 16.23″ E) and Phetchabun province (16° 25′ 27.59″ N, 101° 9′ 42.25″ E) of Thailand, during the period of September-October 2008. The actinomycetes isolates were grown on HT agar at 30 ℃ for 3 weeks. Four-millimeter-diameter agar plugs were cut with a sterile cork borer from the leading edges of colonies, and one such plug was transferred into a 250 ml Erlenmeyer flask containing 100 ml of ISP-2 broth and incubated at 30 ℃ for 3 weeks for preparation of seed culture. One percent of seed culture was propagated in ISP-2 broth supplemented with 0.2% L-tryptophan and incubated in the dark at 30 ℃ with shaking at 120 rev/min for 3 weeks. One percent of seed culture was propagated in peptone water and incubated at 30 ℃ with shaking at 120 rev/min for 3 weeks. One percent of seed culture was propagated in modified Gaus No.1 broth and incubated at 30 ℃ with shaking at 120 rev/min for 3 weeks. Catechol-type siderophores were determined by using Arnow's method (Arnow 1937) and hydroxamate siderophores were determined by using the Csaky test (Csaky 1984).

Healthy leaf, shoot and root tissues of Eaglewood (Aquilaria crassna Pierre ex Lec.) were collected from the plantations in Nakhonnayok province (14° 7′ 20.60″ N, 101° 4′ 16.23″ E) and Phetchabun province (16° 25′ 27.59″ N, 101° 9′ 42.25″ E) of Thailand, during the period of September-October 2008. The actinomycetes isolates were grown on HT agar at 30 ℃ for 3 weeks. Four-millimeter-diameter agar plugs were cut with a sterile cork borer from the leading edges of colonies, and one such plug was transferred into a 250 ml Erlenmeyer flask containing 100 ml of ISP-2 broth and incubated at 30 ℃ for 3 weeks for preparation of seed culture. One percent of seed culture was propagated in ISP-2 broth supplemented with 0.2% L-tryptophan and incubated in the dark at 30 ℃ with shaking at 120 rev/min for 3 weeks. One percent of seed culture was propagated in peptone water and incubated at 30 ℃ with shaking at 120 rev/min for 3 weeks. One percent of seed culture was propagated in modified Gaus No.1 broth and incubated at 30 ℃ with shaking at 120 rev/min for 3 weeks. Catechol-type siderophores were determined by using Arnow's method (Arnow 1937) and hydroxamate siderophores were determined by using the Csaky test (Csaky 1984).

Healthy leaf, shoot and root tissues of Eaglewood (Aquilaria crassna Pierre ex Lec.) were collected from the plantations in Nakhonnayok province (14° 7′ 20.60″ N, 101° 4′ 16.23″ E) and Phetchabun province (16° 25′ 27.59″ N, 101° 9′ 42.25″ E) of Thailand, during the period of September-October 2008. The actinomycetes isolates were grown on HT agar at 30 ℃ for 3 weeks. Four-millimeter-diameter agar plugs were cut with a sterile cork borer from the leading edges of colonies, and one such plug was transferred into a 250 ml Erlenmeyer flask containing 100 ml of ISP-2 broth and incubated at 30 ℃ for 3 weeks for preparation of seed culture. One percent of seed culture was propagated in ISP-2 broth supplemented with 0.2% L-tryptophan and incubated in the dark at 30 ℃ with shaking at 120 rev/min for 3 weeks. One percent of seed culture was propagated in peptone water and incubated at 30 ℃ with shaking at 120 rev/min for 3 weeks. One percent of seed culture was propagated in modified Gaus No.1 broth and incubated at 30 ℃ with shaking at 120 rev/min for 3 weeks. Catechol-type siderophores were determined by using Arnow's method (Arnow 1937) and hydroxamate siderophores were determined by using the Csaky test (Csaky 1984).