Biocontrol of Tomato Fusarium Wilt by a Novel Genotype of 2,4-Diacetylphloroglucinol-producing Pseudomonas sp. NJ134

• Published in: The plant pathology journal Vol. 28; no. 1; pp. 93 - 100
• Main Author: Kang, Beom-Ryong
• Format: Journal Article
• Language: Korean
• Published: 2012
• Subjects: antifungal compound; biological control; genotype
• ISSN: 1598-2254; 2093-9280

The rhizobacterium NJ134, showing strong $in$ $vitro$ antifungal activity against $Fusarium$ $oxysporum$, was isolated from field grown tomato plants and identified as $Pseudomonas$ sp. based on 16S ribosomal DNA sequence and biochemical analyses. The antifungal compound purified by gas chromatography-mass spectrometry, infrared, and nuclear magnetic resonance analyses from NJ134 cultures was polyketide 2,4-diacetylphloroglucinol (DAPG). Analysis of the sequence of part of one of the genes associated with DAPG synthesis, $phlD$, indicated that the DAPG producer NJ134 was a novel genotype or variant of existing genotype termed O that have been categorized based on isolates from Europe and North America. A greenhouse study indicated that about $10^8$ CFU/g of soil NJ134 culture application was required for effective biocontrol of Fusarium wilt in tomato. These results suggest that a new variant genotype of a DAPG-producing strain of $Pseudomonas$ has the potential to control Fusarium wilt under the low disease pressure conditions.