| Southern root-knot nematode (RKN) Meloidogyne incognita , is a serious pest of upland cotton (Gossypium hirsutum L.). This study was to discover inheritance of RKN resistance and to identify associated DNA markers. Parents and two F2 populations used in this research were Resistant Near Isogenic Line (RNIL), Susceptible Near Isogenic Line (SNIL), RNIL x SNIL and RNIL x Stoneville 213 respectively. Gall Index analysis fit a 1:3 and 3:13 segregation ratios (resistant: susceptible). Genotype analysis with 326 Simple Sequence Repeats resulted in 9 polymorphic markers. Regression analysis resulted in BNL 1231, 3545, 3644, and 3661 explaining 11, 12, 16 and 21% of the gall index variation respectively. BNL 3545, 3644 and 3661 were closely linked on the short arm of chromosome 14 and BNL 1231 on the long arm of chromosome 20, based on the deletion analysis of the aneuploid cytogenetic stocks. This indicates that two chromosomes are involved, providing additional support for the 3:13 two-gene inheritance model. |
