Project Number: 6602-21220-013-00
Project Type: Appropriated

Start Date: Apr 09, 2007
End Date: Apr 08, 2012

Objective:
New (additional) objectives per PDRAM memo #HQ01d dated July 5, 2007: 1) Determine whether increased aflatoxin production in nematode-infected peanuts is due to a greater percentage of immature kernels, and the role of nematode infection of roots vs. pods. 2) Determine whether nematode-resistant peanut genotypes reduced the risk of preharvest aflatoxin contamination in soil infected with root-knot nematodes. Identify, characterize, and move genes for resistance to Meloidogyne spp. into cotton and peanut germplasm and cultivars. Utilization, mechanisms, and interactions of classical and contemporary methods in integrated nematode management. Enhance native and introduced antagonists of nematodes in cotton and peanut cropping systems.

Approach:
Field and greenhouse experiments will be conducted to improve management of plant-parasitic nematodes in cotton and peanut. The approach will be multi-tactic including host-plant resistance, antagonistic crops, and biological control. Host-plant resistance to root-knot nematodes is the foundation of our nematode management strategy. Cooperative research will be conducted with plant breeders to develop cultivars and germplasm of peanut and cotton with desirable agronomic traits and a high level of nematode resistance. Plant material will be selected for resistance using traditional and marker-assisted selection. Durability of resistance genes is an important consideration in our research. Towards this end, we will search for new nematode resistance genes to deploy with previously identified resistance genes and determine the frequency and distribution of a species (the northern root-knot nematode) capable of reproducing on resistant peanut. We will also investigate ecologically-based control strategies that can be integrated with resistant cultivars to increase the durability of resistance and control a broader spectrum of nematode pathogens. Specifically, we will determine the potential of Bt toxins, antagonistic cover crops, and antagonistic microorganisms to reduce root-knot and reniform nematode populations. Central to an effective management strategy is a thorough understanding of how nematodes interact with biotic and abiotic factors to reduce crop yield and quality; therefore, we will examine the interaction between root-knot nematodes and water stress, weeds, and fungi that produce aflatoxins. These studies will result in ecologically-based, cost-effective management options to reduce nematode populations, reduce damage from nematodes, and foster natural biological control.