High-resolution fine mapping of ps-2, a mutated gene conferring functional male sterility in tomato due to non-dehiscent anthers

Abstract

Functional male sterility is an important trait for the production of hybrid seeds. Among the genes coding for functional male sterility in tomato is the positional sterility gene ps-2. ps-2 is monogenic recessive, confers non-dehiscent anthers and is the most suitable for practical uses. In order to have tools for molecularassisted selection (MAS) we Wne mapped the ps-2 locus. This was done in an F 2 segregating population derived from the interspeciWc cross between a functionally male sterile line (ps-2/ps-2; Solanum lycopersicum) and a functionally male fertile line (S. pimpinellifolium). Here we report the procedure that has led to the high-resolution Wne mapping of the ps-2 locus in a 1.65 cM interval delimited by markers T0958 and T0635 on the short arm of Chromosome 4. The presence of many COS markers in the local high-resolution map allowed us to study the synteny between tomato and Arabidopsis at the ps-2 locus region. No obvious candidate gene for ps-2 was identiWed among the known functional male sterility genes in Arabidopsis.

ps-2, the gene responsible for functional sterility in tomato, due to non-dehiscent anthers, is the result of a mutation in a novel polygalacturonase gene

“…This population, segregating for ps-2, is composed of 146 F 2 recombinant plants in the ps-2 locus region (Gorguet et al 2006).…”

“…Conversion of the BAC ends sequences into CAPS or dCAPS markers was performed as described by Gorguet et al (2006). Details of the PCR markers derived from BAC ends sequences are presented in Table 1.…”

“…The BAC clone 143M15 was sequenced via the shotgun-sequencing method by Greenomics (The Netherlands). PCR markers derived from the candidate genes identiWed on the BAC sequence were developed as described by Gorguet et al (2006). To identify putative genes, the Wnal BAC DNA sequence was scanned against the tomato Unigene database from SGN (Mueller et al 2005) and the Arabidopsis gene models database from TAIR (http://www.Arabidopsis.org; Huala et al 2001), using the TBLASTX interface of SGN (Mueller et al 2005), with a signiWcance threshold of 1E ¡10 .…”

“…To identify putative genes, the Wnal BAC DNA sequence was scanned against the tomato Unigene database from SGN (Mueller et al 2005) and the Arabidopsis gene models database from TAIR (http://www.Arabidopsis.org; Huala et al 2001), using the TBLASTX interface of SGN (Mueller et al 2005), with a signiWcance threshold of 1E ¡10 . The PCR markers based on putative ORF sequences were developed and screened on the recombinant population as described by Gorguet et al (2006). Details of these PCR markers are given in Table 1.…”

“…We have recently Wne-mapped the positional sterility-2 gene, conferring non-dehiscent anthers in tomato (Gorguet et al 2006). Here, we report the isolation of the ps-2 gene by positional cloning.…”