Location: Crop Genetics and Breeding Research
Project Number: 6048-21220-016-000-D
Project Type: In-House Appropriated
Start Date: Apr 9, 2017
End Date: Mar 27, 2022
Objective:
1. Identify and characterize nematode resistance genes and work with breeders to combine them with commercially valuable agronomic traits in cotton and peanut.
1.A. Determine the phenotypic expression of Meloidogyne arenaria resistance in peanut isolines 48 (moderate resistance) and 46 (high resistance).
1.B. Evaluate the phenotypic expression of the Meloidogyne incognita resistance QTLs qMi-C11 and qMi-C14 in cotton isolines.
1.C. Identify sources of resistance to Meloidogyne incognita in cotton that differ from Auburn 623 RNR.
1.D. Identify specific Meloidogyne-resistance genes within quantitative trait loci (QTL) regions and determine their functions in cotton and peanut.
2. Evaluate antagonist-nematode interactions, and develop novel integrated strategies, including biological control methods for management of nematodes in cotton, peanuts, and biofuel crops.
2.A. Evaluate environmental factors that influence Pasteuria penetrans endospore movement in soil and attachment to nematodes.
2.B. Monitor changes in adhesion phenotypes of Pasteuria penetrans to determine the drivers of phenotypic/genetic changes occurring in a population of the bacterium and its host, Meloidogyne arenaria.
2.C. Evaluate factors that affect the general suppression of Meloidogyne spp. in field soil.
2.D. Evaluate integrated management options including resistance, suppressive cover crops, and an improved decision model for managing Meloidogyne incognita.
Approach:
Field and greenhouse experiments will be conducted to develop management options for root-knot nematodes in cotton and peanut. We plan a multi-tactic approach utilizing host-plant resistance (Objective 1), crop rotation, antagonistic crops, seed treatments, and biological control (Objective 2). Host-plant resistance to nematodes is the cornerstone of our strategy. We will determine mechanisms of resistance in cotton and peanut, determine effects of nematode resistance genes on the Fusarium wilt disease complex in cotton, and try to identify new resistance QTLs in cotton. However, we cannot rely exclusively on host-plant resistance for managing nematodes. 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 nematodes. Specifically, we will evaluate factors that influence the ability of the nematode-parasitic bacterium Pasteuria penetrans to suppress nematodes; determine whether frequency-dependent selection occurs between the bacterium and its host; and determine whether considering P. penetrans abundance improves nematode management decisions. We will evaluate the effects of winter cover crops on the natural suppressiveness of soils to nematodes; evaluate integrated management options including combining high residue rye with resistant cotton cultivars and nematicidal seed treatments; and evaluate nematode suppression and crop damage in the novel crop rotation of cotton with double cropped sweet sorghum (summer crop) and sugar beet (winter crop).
