Use of ISSR fingerprints to detect microsatellites and genetic diversity in several related Brassica taxa and Arabidopsis thaliana

摘要

Brassicaceae is one of the most cultivated and important plant families around the world and several members are used as plant model. The genome divergence between the tribes of Arabidopsis and Brassica species has been estimated to be 20 or 28 millions years old (Wroblewski et al. 2000; Koch et al. 2001) but a high similarity and collinearity between chromosomes has been reported (Kowalski et al. 1994; Lagercrantz et al. 1996). The main Brassica crops have a special genetic relation described by U (1935) and called triangle of U. Molecular analysis have confirmed such relation between the 3 diploid genomes (B. rapa=genome AA, B. nigra=genome BB and B. oleracea=genome CC) and the 3 amphidiploids genomes (B. napus=genome AACC, B. juncea=genome AABB and B. carinata=genome BBCC) (Erickson et al. 1983, Warwick and Black 1991).Polymorphism between species can result from different events and is an important aspect of plant breeding. Microsatellites (SSR) represent the most abundant source of polymorphism from repetitive sequences. SSR are often used as molecular markers even if this technology is time-consuming and expensive. Inter simple sequence repeat (ISSR) is an alternative technique to study polymorphism based on the presence of microsatellites through-out genomes (Zietkiewicz et al. 1994). ISSR markers are DNA sequences delimited by two inverted SSR composed of the same units which are amplified by a single PCR primer, composed of few SSR units with or without anchored end. ISSR-PCR gives multilocus patterns which are very reproducible, abundant and polymorphic in plant genomes (Zietkiewicz et al. 1994; Bornet and Branchard 2001; Bornet et al. 2002a). Comparison of ISSR and other PCR-based markers have shown their efficiency in plant breeding (Adams et al. 2003; Archak et al. 2003; Galvan et al. 2003). As a result of these advantages and their universality and easiness of development (no needs to sequence data), ISSR markers are more and more requested.In this paper, we report the use of ISSR fingerprints as indicator of the abundance of SSR units between Brassica and Arabidopsis thaliana genomes and their use to assess genetic diversity between these species.