Journal of Zhejiang University SCIENCE
(ISSN 1009-3095, Monthly)
2003   Vol. 4   No. 4   p.463-468

Diversity of Gram negative bacteria antagonistic against major pathogens of rice from rice seed in the tropic environment

XIE Guan-lin(谢关林)(Istitute of Biotechnology,Zhejiang University,Hangzhou 310029,China)
SOAD Algam(Istitute of Biotechnology,Zhejiang University,Hangzhou 310029,China)
SWINGS J.(Lab of Microbiology, University of Gent, Gent, Belgium)
MEW T. W.(Entomology and Plant Pathology Division, International Rice Research Institute, Manila, Philippines)

Abstract:With the use of a seed washing technique, more than 4000 Gram negative bacteria were isolated by two improved isolation methods from 446 batches of 1 kg rice seed samples obtained from 22 provinces in the Philippines. They were initially characterized on the basis of colony morphology and results of biochemical and pathogenicity tests. Six hundred and fifty-two strains were further identified by Biolog, from which 133 were selected for fatty acid methyl ester (FAME) analysis together with 80 standard reference!strains. Sixteen species or types of Pseudomonas and 17 genera of non-pseudomonads were identified, more than one third of which have not been recorded in rice. The most predominant species observed were P. putida and P. fulva. About 17% of the strains of Pseudomonas and 2% of the non-pseudomonads were antagonistic to one or more fungal or bacterial pathogens of rice. Rice seed is an important source of biological control agents.
Keywords:Rice seed, Non-pathogenic bacteria, Antagonistic bacteria, Pseudomonas

CLC Number:S432.4 Document ID:A

Foundation Item:Project supported by Belgium government and Asia Development Bank. Part of the experiments conducted at the University of Gent , Belgium and IRRI during 1997-2000.
Author Resume:XIE Guan-lin (谢关林),E-mail: glxie@zju.edu.cn;SOAD Algam,PhD student in Zhejiang University now, from Khartoum University of Sudan, Sudan

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Manuscript Received:2002 May 6

Manuscript Revised:2002 July 12

Published:2003 Aug. 30