In Vitro Screening of Biological Control Agents on Meloidogyne Incognita
N. Xiang
K. S. Lawrence
J. W. Kloepper
J. A. Mcinroy
Department of Entomology & Plant Pathology
Auburn University, AL
Abstract
Meloidogyne incognita (Southern Root-knot Nematode, RK) is the most damaging pathogen on cotton in the U.S. and causes great yield loss. Due to its extremely wide range of hosts, crop diseases caused by RK are usually very difficult to manage. The objective of this research project is to select potential biocontrol agents that paralyze the RK infective stage juveniles (J2s). The commercial products (Aeris, Avicta, and Temik) and 19 Bacillus strains were evaluated in vitro. RK J2s were hatched from eggs by using a warmer at 31°C for 5-7 days. An in vitro assay was established in 100 µl 96-well plate with 30-40 J2s in each well at 25°C to evaluate the effect of paralysis of the J2s. Each treatment had four replications and each trial was repeated twice. Numbers of live J2s were counted and recorded before exposure and 48 hours after treatment. Data collected from each trial were analyzed in SAS 9.2 (SAS Institute, Inc.) by using the PROC GLIMMIX procedure with P ≤ 0.05. Eleven Bacillus strains paralyze 70% or more of the RK J2s. Temik 15 G paralyzed 100% of the RK J2s. The selected Bacillus strains from the in vitro screening will be evaluated in the greenhouse for further selections. Field trial will be established in 2014 and may provide more options for growers to manage the nematode disease on cotton and prevent yield loss.