Genetic diversity and relationships among 47 loquat varieties revealed by EST-SSR markers

• Genetic diversity and relationships of loquats were studied using EST-SSR markers from apple.
• We report a comparatively high transferability rate of 67.3% in loquat.
• Most of the PCR products contain the SSR loci.
• The cluster analysis obtained agrees with the origins of the cultivars.

The genetic diversity and relationships of 47 loquat varieties sourced from different geographic locations were studied by using EST-SSR markers derived from apple. Results show that 33 pairs of apple EST-SSR primers had clear amplification products in loquat cultivars, with a comparatively high transferability rate of 67.3% in loquat, among which 22 pairs of primers could amplify polymorphic PCR products. Otherwise, among the 29 recovered fragments, 80% of the PCR products contained the SSR markers. The genetic relationships of all the 47 loquat accessions were analyzed by using polymorphic EST-SSR markers, showing that these markers could clearly separate loquat samples. Based on the cluster analysis, all the loquat varieties clustered into two groups with accessions from China and Spain respectively. The clusters obtained agree with the origins of the cultivars. This study confirms that the EST-SSR markers from apple are suitable for studying genetic diversity among loquat varieties. The polymorphic markers obtained will be used for loquat genotyping in further studies.