The invention discloses a
gene associated with cotton
fiber length and application, and belongs to the field of
biotechnology application. The cDNA (
complementary deoxyribonucleic acid) sequence of the
gene GhDTX48 associated with the cotton
fiber length character is shown as SEQ ID NO. 1, and the
genome sequence is shown as SEQ ID NO. 2. The
gene GhDTX48 is regulated and controlled by an adjacent SNP site (D11: 24631774), the SNP basic group is mutated from T to C, and the length of
genotype fiber after
mutation is obviously greater than that before
mutation. The invention further provides a method for identifying the variety of the long-fiber cotton, and the cotton with the basic group C corresponding to the SNP site is the variety of the long-fiber cotton. Meanwhile, a new variety of cotton long fibers is cultivated through a
genetic engineering means, a gene containing a high-yield
genotype GhDTX48 (C) is transferred into a cotton variety, or an SNP site in a low-yield
genotype GhDTX48 (T) is subjected to site-specific
mutagenesis to form (C), so that the new variety of cotton long fibers is cultivated. The gene has important research value and application prospect in efficient identification of long-fiber cotton varieties and improvement and breeding of excellent cotton varieties.