Author
VAN BECELAERE, GUILLERMO - UNIVERSITY OF GEORGIA | |
MAY, LLOYD - UNIVERSITY OF GEORGIA | |
Davis, Richard | |
SHEIKH, NAZMOON - UNIVERSITY OF GEORGIA | |
CHEE, PENG - UNIVERSITY OF GEORGIA |
Submitted to: Cotton Research and Extension Report
Publication Type: Experiment Station Publication Acceptance Date: 5/3/2004 Publication Date: 5/15/2004 Citation: Van Becelaere, G., May, L., Davis, R.F., Sheikh, N., Chee, P.W. 2004. Development of DNA markers for root-knot nematode resistance in cotton. 2003 University of Georgia Cotton Research and Extension Report. p.59-61. Interpretive Summary: Technical Abstract: Diagnostic markers for root-knot nematode resistance genes will greatly accelerate development of resistant cultivars. The objective of this study is to develop diagnostic DNA markers for genes conferring resistance to root-knot nematodes in cotton. An F2 population was created in which nematode resistance was segregating. Plants in a greenhouse were inoculated with nematodes, DNA was extracted from F2 plants, and plants were evaluated for nematode resistance. Approximately 200 restriction fragment length polymorphism (RFLP) markers 20-25 centimorgans apart were selected to cover the entire cotton genome and were used to screen the 16 most resistant and 16 most susceptible F2 plants. The relationship between the RFLP markers and nematode resistance was determined by regression analysis. Markers associated with resistance then were used to screen the whole population to confirm the association. The distribution of galling in the F2 plants was skewed towards the resistant parent, which suggests that only a few genes control the resistance. Screening has been completed with over 130 RFLP markers which cover more than 70% of the genome. Statistical analyses performed on this data have detected seven chromosomal regions associated with nematode resistance, which means that a resistance gene may be present in these regions. The chromosome regions around these markers are being investigated in more detail by testing additional markers that are closely linked to them. |