Monday, November 13, 2006
37-8

Green Manure Effects on Soil Microbial Community in a Root-Knot Nematode (Meloidogyne javanica) Control System in Taro (Colocasia esculenta).

Andrea L. Blas1, Qingyu Yu2, Brent Sipes1, Ray Ming3, and Susan Miyasaka1. (1) Univ of Hawaii-Manoa, 1955 East-West Rd, Agricultural Sciences 218, Honolulu, HI 96822, (2) Hawaii Agriculture Research Center, 99-193 Aiea Heights Dr, Ste 300, Aiea, HI 96701, (3) Univ of Illinois at Urbana-Champaign, 1201 W. Gregory Dr, 288 ERML, MC-051, Urbana, IL 61801

A single gram of soil has been estimated to contain 4,000-10,000 different bacterial genomes of which less than 1% can be readily cultured.  Use of commercial nematicides in agricultural production has been shown to cause shifts in the soil microbial community to members capable of metabolizing and degrading the nematicidal compound.  ‘Sordan 79,’ a sorghum x sudangrass hybrid, is currently being evaluated for root-knot nematode (RKN) control in subsequent taro crop in Hawaii.  In this study, we characterize changes in the soil microbial community in response to green manure treatment.  Diversity indices for preliminary soil microbial profiles generated using full-length 16S rDNA sequences indicate fewer microbial species at the end of the green manure decomposition period (Chao1 = 442 ribotypes) than at the end of the green manure growth period (Chao1 = 925 ribotypes).  More comprehensive community profiles will be generated using serial analysis of ribosomal sequence tags (SARST) to determine the particular community segments being impacted by green manure treatment.