【Objective】This research attempts to provide theoretic guidance in high photosynthetic efficiency molecular marker- assisted breeding of cooton by QTL mapping for the chlorophyll content and photosynthetic rates in Xinjiang upland cotton.【Method】In this paper,a genetic linkage map was constructed by180 F2 segregation population derived from a cross between ZX1789 × E56. The chlorophyll content and photosynthetic rates of the F2 plants and the F2: 3family lines were analyzed by composite interval mapping( CI...