Identification of AFLP-derived SCAR markers linked to the pear scab resistance gene.

Pear scab is one of the most harmful diseases in pear production.Using 97 F1 progenies produced by the cross'Yali'(susceptible)×'Xueqing'(resistant),markers linked to pear scab resistance gene were screened by amplified fragment length polymorphism(AFLP) technique combined with bulked segregant analysis(BSA)method.Two molecular markers which linked to pear scab resistant gene had been identified from 64 pairs of AFLP primer,named as ACA/CAA-179 and AAC/CAG-198.The genetic distance to pear scab resistant gene were 5.2 cM and 8.3 cM,respectively.Sequencing results indicated that the length of the two specific fragment amplified were 179 bp and 198 bp,respectively.The specific primers were further designed based on the sequence information,and then were utilized to analyze the F1 population by PCR.Results showed that AFLPACA/CAA-179 had been successfully converted into SCAR marker,and named as SCAR-117.This result will be helpful for molecular identification of germplasm and early selection of progenies which are resistant to pear scab.