Assessment of Predacity and Efficacy of Arthrobotrys dactyloides for Biological Control of Root Knot Disease of Tomato

Abstract

Five isolates of Arthrobotrys dactyloides were isolated from different locations of India and their in vitro predacity was tested against Meloidogyne incognita (J 2 ), Tylenchorhynchus brassicae and Hoplolaimus indicus. All isolates of A. dactyloides captured and killed M. incognita and T. brassicae but not H. indicus. The isolates also differed in their predacity of the first two nematode species. The application of mass culture of A. dactyloides in soil infested with 2000 juveniles of M. incognita per ÔkgÕ before planting of tomato seedlings reduced the number of root knots by 5.6-45.6%, of females by 44.7-72.9%, of egg masses by 44.5-51.3% and of juveniles by 37.9-81.8% and increased the plant growth in a pot experiment. The effect of this fungus as biocontrol agent was enhanced when its mass culture was applied with cow dung manure, which reduced the number of root knots by 61.7-66.6%, of females by 80.6-94.7%, of egg masses by 80.3-89.6% and of juveniles by 68.1-88.0%.www.blackwell-synergy.com

Trap Induction and Trapping in Eight Nematode-trapping Fungi (Orbiliaceae) as Affected by Juvenile Stage of Caenorhabditis elegans

“…Nematode size determined the possibility to be captured in constricting rings [34], which may explain why the percentage of C. elegans trapped by Dr. stenobrocha was lower with J4 than with J2 or J3 even though the J4 induced more constricting rings. Kumar and Singh [31] and Drechsler [7] also showed that large nematodes could not enter the constricting rings of Dr. dactyloides, which agreed with our partial correlation analysis that the juvenile size was negatively correlated with trapping by Dr. stenobrocha. While higher juvenile motility could increase the opportunities of nematode to enter constricting rings and to be trapped.…”

“…In addition to differences in nematode motility, differences in the nematode cuticle [20] and nematode size might also explain differences in how nematodes induce traps and are trapped. Although Kumar and Singh [31] found that the nematode Hoplolaimus indicus induced fewer constricting rings of Drechslerella dactyloides than Meloidogyne incognita or Tylenchorhynchus brassicae;in spite of its larger size, the constricting ring induction of Dr. stenobrocha was positively correlated with juvenile size in this study, indicating that other factors such as the nematode cuticle characteristics may influence the formation of constricting ring.…”

Screening of Different Media and Substrates for Cultural Variability and Mass Culture ofArthrobotrys dactyloidesDrechsler

“…Stirling et al (1998) and Stirling and Smith (1998) reported that formulation of A. dactyloides successfully reduced the severity of root knot disease of tomato in pot and field experiments. In this continuation, recently Kumar and Singh (2005) reported that application of A. dactyloides at the rate of 4 × 10 6 colony forming unit (CFU) per kg of soil successfully reduced the number of root knot up to 66% in tomato.…”

Genomic Insights into the Adaptation to Parasitism in Nematode-Trapping Fungi and Transcriptomics during Infection of Caenorhabditis Briggsae and Plant-Parasitic Nematodes

“…Application of mass culture of Arthrobotrys dactyloides and Dactyalria brochopaga grown on barley substrates by method developed by Kumar et al (2005) was found effective against the root-knot disease of tomato and rice. The number of root knots, females, egg masses and second stage juveniles of root knot nematodes were found to reduce by the application of colony forming units of A.datyloides and D.brochopaga in tomato and rice (Kumar and Singh, 2006;Singh et al, 2007).…”