Identification of genotypes using AFLP markers in apple rootstocks

This experiment was carried out to identify 12 genotypes of apple rootstock (Malus) using AFLP markers in 1996-1997. The materials tested are widely used in China apple production, including CG24, CG57, B9, B490, SH7, SH9, S63, Ottawa 3, Balenghaitang, Shandingzi, Xiaojinhaitang, and Ningxia 8. The enzymes for restriction digestion of genomic DNA are PstI and MseI. Radioisotope method (gamma-P-33 ATP) had been used for AFLP detecting. Primer selection was performed after the AFLP analysis system was constructed. It is found that the PstI-AAC / Msel-GAC is an ideal primer combination for AFLP fingerprinting construction of apple rootstocks. The primer had detected 105 sites of the apple genomic DNA, and 67 polymorphic sites among them. The ratio of polymorphic sites to total amplification sites is 63.8%. The fingerprinting map can be divided into three areas. The area I, II and III are long fragment area, middle fragment area, and short fragment area respectively. The polymorphism decreases from I to III area. The AFLP fingerprinting is very clear with brightness background. All 12 genotypes of apple rootstock tested have been identified through their specific bands on the AFLP fingerprinting.