|DE Jin, Rong - CHONNAM NATIONAL UNIV|
|Won Suh, Joo - MYONG JI UNIVERSITY|
|Dong Park, Ro - CHONNAM NATIONAL UNIV|
|Woong Kim, Yong - CHONNAM NATIONAL UNIV|
|Kim, Kil-Yong - CHONNAM NATIONAL UNIV|
Submitted to: Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 29, 2004
Publication Date: March 1, 2005
Citation: De Jin, R., Won Suh, J., Dong Park, R., Woong Kim, Y., Krishnan, H.B., Kim, K. 2005. Effect of chitin compost and broth on biological control of meloidogyne incognita on tomato (lycopersicon esculentum mill.). Nematology. 7(1):125-132. Interpretive Summary: The root-knot nematode causes serious damage to important crops world-wide resulting in significant loss of revenue. Resistant cultivars, crop rotation, soil fumigation, and chemical nematicides have traditionally been used for management of the root-knot nematodes. Longevity and slow degradation rate of chemical nematicides creates potential environmental and human health concerns. These concerns have forced researchers to find innocuous yet efficacious methods of nematode control. Several soil microbes, which produce an array of biologically active compounds, can serve as potential biological control agents. In this study, we have demonstrated chitinase producing soil microbes can significantly protect tomato plants from root-knot nematode invasion. Information obtained from this study demonstrates that chitinase-producing soil bacteria could be utilized as potential biocontrol agents of nematodes. This practice should reduce the use of undesirable synthetic chemicals and promote maximum yield of important vegetable crops.
Technical Abstract: Plant-parasitic nematodes are distributed worldwide and affect a broad range of important agronomic plant species. Chitinolytic bacteria were evaluated as potential biological control agents of the root-knot nematode, Meloidogyne incognita, on tomato. After transplantation of seedlings into pots containing soil amended with chitin compost, chitin broth, or respective controls, soil was inoculated with nematode eggs and infective second-stage juveniles (J2). Samples taken at 4, 6, and 8 weeks after inoculation indicated that fresh weights of plants did not vary between treatments or between treatments and controls. The gall index was lower in the plants grown in the chitin-amended soil at each time point. Activities of soil chitinase and beta 1,-3-glucanase were greater in those soils amended with chitin compost and chitin broth. Gall index of tomato root was negatively correlated with soil chitinase activity. Activities of tomato root chitinase and beta 1,-3-glucanase were higher in plants growing in non-chitin-amended soil at 6 and 8 weeks after nematode infestation. Chitinase activity in tomato root was positively correlated with the gall index of tomato root. The results indicate the potential of chitinase producing bacteria to alleviate nematode parasitism in important vegetable crops.