Project Number: 6402-22000-005-00
Project Type: Appropriated

Start Date: Mar 05, 2007
End Date: Mar 04, 2012

Objective:
Evaluate tetraploid cotton germplasm for host plant resistance to reniform nematode. Begin introgression of genes for host plant resistance to reniform nematode into tetraploid upland cotton from candidate diploid A-genome germplasm. Evaluate the impact of biotic and abiotic crop production factors on reniform nematode populations in Mississippi. Assess the efficacy of cultural and chemical management options to minimize losses to reniform nematode in Mississippi.

Approach:
Stabilize the phenotype of day-neutral Texas race stock lines with moderate levels of resistance to reniform nematode through self pollination, and characterize the heritability and action of genes involved in resistance in these tetraploid lines. Develop a phenotypic screening technique that evaluates root infection by reniform nematode and also allows the evaluated plant to survive to reproductive maturity. Determine if enough variability exists within reniform nematode populations to allow them to adapt to overcome host resistance. Improve efficiency and effectiveness of methods necessary to introgress genes from diploid A-genome Gossypium species into tetraploid G. hirsutum germplasm by choosing the most compatible lines and by developing methods to reduce endogenous contamination of in-vitro ovule cultures without inhibiting their development. Introgress reniform nematode resistance from G. arboreum accession A2-190 into G. hirsutum. Describe the influence of crop production practices such as irrigation, tillage, and planting date on reniform nematode population density. Evaluate the role of weeds as hosts for reniform nematode and determine their importance in maintaining inoculum levels of the nematode. Evaluate adapted cotton lines for tolerance to reniform nematode. Determine effectiveness of new commercial seed treatment nematicides for managing reniform nematode, compared to in-furrow nematicide applications. Determine if a combination of nematicide and rotation to corn will improve reniform nematode suppression over rotation used alone.