EST libraries development in Asparagus officinalis for SNPs discovery

In order to conduct marker-assisted selection (MAS) in asparagus the first broad survey of EST-SNPs (Expressed Sequence Tag-Single Nucleotide Polymorphisms) in A. officinalis specie was generated; more than 200,000 Asparagus officinalis ESTs were sequenced and assembled starting from two GSFLX 454 pyrosequencing runs on two parental genotypes sharing a higher part of their genetic background and divergent at least for Puccinia asparagi resistance trait (male genotype named G190 as resistant, female genotype named 1770 as susceptible ones). Efficient computational SNPs mining pipeline based on a sequence polymorphisms detection tool was developed, finding more than 1700 putative G190/1770 SNPs within expressed sequences. Stringent post-processing reduced this number to 284 putative SNPs and a panel of these was successfully validated by Sanger sequencing. Expressed sequence tag databases are a valuable resource of gene-rich DNA sequence information for a species, additionally that can be mined for the development of genetic markers as SNPs. Once discovered, SNPs can be converted into genetic markers that can be inexpensively assayed in a highthroughput manner and it can be used to generate very dense genetic maps. Until now, there are few deposited Asparagus EST sequences, especially for A. officinalis, and the repository of a massive number of those from our study can be useful for genome sequence annotation and, especially, for continued advancement of Asparagus genomics research