Abstract:

The primers for SCoT marker analysis were designed based on the short conserved region surrounding the ATG translation start codon. However, the SCoT technique was not found yet to be applied in citrus. In the present research, we collected 24 sweet orange clones from Hunan Province and analyzed by using SCoT marker to investigate their genetic variation. The amplified SCoT fragments were sequenced. The results showed that an optimal 20 μL reaction system of SCoT included 2.0 μL 10xPCR buffer, 1.6 U Taq DNA polymerase, 80 ng template DNA, 0.3 mmol/L dNTPs, 0.2 μmol/L primer and 1.6 mmol/L Mg2+. Application of this reaction system to fingerprint the sweet orange clones produced clear bands with good repeatability and reproducibility. The PCR products were of 100 to 1091 bp in size. After being sequenced, the polymorphisms could distinguish 12 sweet orange clones and pummelo. The BLAST result showed that part of the SCoT fragments coding region had high homology to ribosomal protein S3 N superfamily. The other sweet orange clones should be studied further.