The invention relates to a sterile line selective-breeding and
hybrid breeding method of pest-resistant and low-
gossypol natural
colored cotton. The sterile line selective-breeding and
hybrid breeding method is characterized in that low-
gossypol Shandong cotton-12 as a female parent and pest-resistant Shandong cotton
research center (SCRC)-21 as a male parent are subjected to hybridization matching, and in the F2 generation group, plants of which cotyledons, stems and leaves do not contain
gossypol are selected and a low-gossypol cotton line 8HN538 is obtained after continuous
selfing plantation of the plants for 3-4 generations; a pest-resistant genic male sterile line variety Shandong RH-1 as a female parent and a nut-brown low-gossypol natural
colored cotton parent 00S17 as a male parent are subjected to hybridization matching, pest-resistant plants in the F2 generation group are retained, and male fertile low-gossypol cotton plants are selected and are used for
pollination on low-gossypol cotton male sterile plants; nut-brown cotton
offspring is selected and retained; a continuous selective-hybridization process is carried out until the 4th generation so that a pest-resistant low-gossypol natural
colored cotton genic male sterile line 0-173-3A is obtained; and the low-gossypol cotton line 8HN538 having pest resistance as a male parent and the pest-resistant low-gossypol natural colored cotton genic male sterile line 0-173-3A as a female parent are subjected to hybridization matching plantation so that the pest-resistant and low-gossypol natural colored cotton
hybrid is obtained. The pest-resistant and low-gossypol natural colored cotton hybrid has a high yield, good
fiber quality and a stable and uniform color, does not contain gossypol in cotton seeds, and greatly improves a comprehensive utilization value.