Genetic analysis of seed-soluble oligosaccharides in relation to seed storability of Arabidopsis

Seed oligosaccharides (OSs) and especially raffinose series OSs (RSOs) are hypothesized to play an important role in the acquisition of desiccation to lerance and consequently in seed storability. In the present work we analyz ed the seed-soluble OS (sucrose, raffinose, and stachyose) content of sever al Arabidopsis accessions and thus identified the genotype Cape Verde Islan ds having a very low RSO content. By performing quantitative trait loci (QT L) mapping in a recombinant inbred line population, we found one major QTL responsible for the practically monogenic segregation of seed stachyose con tent. This locus also affected the content of the two other OSs, sucrose, a nd raffinose. Two candidate genes encoding respectively for galactinol synt hase and raffinose synthase were located within the genomic region around t his major QTL. In addition, three smaller-effect QTL were identified, each one specifically affecting the content of an individual OS. Seed storabilit y was analyzed in the same recombinant inbred line population by measuring viability (germination) under two different seed aging assays: after natura l aging during 4 years of dry storage at room temperature and after artific ial aging induced by a controlled deterioration test. Thus, four QTL respon sible for the variation of this trait were mapped. Comparison of the QTL ge netic positions showed that the genomic region containing the major OS locu s did not significantly affect the seed storability. We concluded that in t he studied material neither RSOs nor sucrose content had a specific effect on seed storability.