Submitted to: Acta Horticulturae
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/20/2004
Publication Date: 4/20/2005
Citation: Bassil, N.V., Neou, C., Postman, J.D. 2005. Pyrus microsatellite markers developed from genbank sequences. Acta Horticulturae. 671:289-292. Interpretive Summary: Our objectives were to develop molecular tools capable of characterizing the diversity of the Pyrus collection of the U.S. Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository. We searched the public gene database housed at the National Center of Bioinformatics Institute (NCBI) for pear DNA sequences. These DNA sequences will be used to develop molecular tools for fingerprinting pear. Out of 18 short repeated pieces of DNA that were obtained, ten were dissimilar in different types of pears. Our laboratory will be testing these ten short pieces of DNA for their ability to distinguish between types of pear.
Technical Abstract: Our objectives were to develop molecular markers capable of characterizing the diversity of the Pyrus collection of the U.S. Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository. Simple sequence repeat (SSR) or microsatellite markers have become the marker of choice for genotype identification. A method was developed to identify microsatellite-containing SSRs from existing pear GenBank sequences. We screened 366 genomic, mRNA and expressed sequence tag (EST) Pyrus nuclear sequences and identified 47 that contained SSRs. Primer pairs were designed for 18 sequences and the optimum annealing temperature was determined by gradient PCR. The SSR primers were able to amplify a product in eight cultivars of P. communis, three cultivars of P. pyrifolia and one Pyrus hybrid ('Nijisseiki' x 'Anjou'). Three primer pairs amplified fragments larger than the expected size and were not pursued further. The remaining 15 primer pairs amplified fragments of the expected size, and 10 of them appeared to show polymorphism. These 10 polymorphic loci are being used to characterize the Pyrus collection at the NCGR.