Microsatellite markers from sugarcane (Saccharum spp.) ESTs cross transferable to erianthus and sorghum

Analysis of a sugarcane (Saccharum spp.) EST (expressed sequence tag) libra ry of 8678 sequences revealed approximately 250 microsatellite or simple se quence repeats (SSRs) sequences. A diversity of dinucleotide and trinucleot ide SSR repeat motifs were present although most were of the (CGG)(n), trin ucleotide motif. Primer sets were designed for 35 sequences and tested on f ive sugarcane genotypes. Twenty-one primer pairs produced a PCR product and 17 pairs were polymorphic. Primer pairs that produced polymorphisms were m ainly located in the coding sequence with only a single pair located within the 5' untranslated region. No primer pairs producing a. polymorphic produ ct were found in the 3' untranslated region. The level of polymorphism (PIC value) in cultivars detected by these SSRs was low in sugarcane (0.23). Ho wever, a subset of these markers showed a significantly higher level of pol ymorphism when applied to progenitor and related genera (Erianthus sp. and Sorghum sp.). By contrast, SSRs isolated from sugarcane genomic libraries a mplify more readily, show high levels of polymorphism within sugarcane with a higher PIC value (0.72) but do not transfer to related species or genera well. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.