|11-935 Project Manager: D. C. Jones|
TESTING FOR RENIFORM AND ROOT-KNOT NEMATODE RESISTANCE IN MISSISSIPPI COTTON BREEDING LINES VIA MARKER ASSISTED SELECTION
Peggy S. Thaxton, Mississippi State University
Breeding lines were developed by crossing reniform nematode immunity/resistance from LONREN, GB713 and other sources (G. barbadense derivatives) and root-knot (RK) nematode resistance into MAFES breeding lines via conventional plant breeding protocols. Leaf samples from individual plants were screened via marker-assisted selection (MAS) (public domain markers) to identify reniform nematode and root-knot nematode resistant plants within plants identified. Plots for MAS were planted on May 19 at Stoneville, MS. Total of 5890 plants representing 3480 F2 plants and 1200 F2F3 plants tagged for IPS, and 1210 F2F3 plants from progeny rows for testing homogeneity were tagged for MAS.
248 individual plants were selected based on the presence of the RN and/or RK markers and yield potential. Selections will be planted for further testing for homogeneity, yield and fiber evaluation. Weight/plant and lint percent are very variable. F2 lint percent is generally low ranging from 27.1 to 43.9. 129 nematode resistant populations were tested for homogeneity. Unfortunately, 43% of these populations were not homogeneous ranging from zero to 70% of the plants tested not having the Lonren marker, and 15 of those populations had all of the 10 plants not having the marker. This is a major concern and is being investigated. Twenty-five breeding lines were selected to go forward based on homogeneity and field observations. Lint yield for the plot ranged from 1346 lb/a to 530 lb/a with the parents averaging 832 lb/a. Eleven of the lines yielded over 1000 lb/a.
Thirty-two advanced lines selected based on high yield and fiber quality from 2010 with four checks were tested (Test A) in 2011 for a replicated yield trial. Nematode counts were above threshold throughout the season. Yields ranged from 1314 lb/a to 653 lb/a with a test average of 787 lb/a. Most of the lines yielded higher than the commercial checks and similar lint percent. Test B included lines that in 2010 were good yield and average fiber quality. Yield ranged 1024 lb/a to 590 lb/a with test average of 794 lb/a.
Development of breeding lines/cultivars with resistance to both root-knot and reniform nematodes has been very successful but requires further testing. The goal of this project is to stack root-knot and reniform genes for resistance into a single genotype for the formal release of one or more root-knot/reniform nematode resistant breeding lines or varieties as quickly as possible to reduce cost of production to Mississippi cotton producers.
|Project Year: 2012|
Search 2012 Projects:|
▸ New Mexico
▸ North Carolina
▸ South Carolina
▸ Cotton Incorporated Fellow
▸ Crop Improvement
▸ Production Efficiency
▸ Sustainable Cotton
▸ Variety Improvement
▸ All Project Nos.