[Analysis on linkage inheritance of sub-red plant mutant from upland cotton]

Analysis of linkage inheritance of sub-red plant, a natural mutant from upland cotton, was conducted by two-point test using parents Gossypium barbadense Hai7124 and G. hirsutum B026 both with petal spots and green leaves, and G. hirsutum E083 with normal white flowers and, sub-red plants. The average percentage of recombination was 1.35% when calculating test-cross combining populations derived from E083/B026//Su9701 and B026/E083//Su9701. The average percentage of recombination was 2.94% when calculating test-cross combining populations derived from E083/Hai7124// Su9701 and Hai7124/E083//Su9701. Meanwhile, the genetic stocks having genotype Rs, Lc1, r2, and rs, lc1, and R2 were used in the three-point test, which demonstrated that the mutant gene Rs was located between genes Lc and R2. The genetic distance between Rs and Lc1 was 42.21 cM, and 1.68 cM between Rs and R2. Coefficient of interference among R2, Lc1, and Rs was 0.79, indicating that the single cross between Rs and R2 has less impact on the other single cross between Rs and Lc1. Based on known genetic distance around gene Rs, the genetic linkage map was drawn. Rs is located between genes Lc1 and R2, molecular marker NAU2863, NAU3735 and NAU3735, NAU1048. The genetic distances between Rs and two markers NAU3735, NAU1048 are 0.1 and 0.2 cM, respectively.