title: DNA resequencing of cotton:RIL49
design: 1)The qualified genomic DNA sample was randomly broken into specific fragments by physical methods and then repaired by terminal repair, and the A base was connected at the 3' end; 2)The specific sequencing primer was connected to the DNA fragment;3) The connected product was purified, and the DNA fragment with appropriate size was selected;4) The connected product was amplified by PCR on the PCR instrument, and the DNA fragment with the target size was selected;37) The quality of the constructed library was detected.