| Taxonomy and phylogenetic relationships within the Secale genus have been a subject of controversy because of the difficulty in identification of Secale taxa. This study utilized amplified fragment length polymorphisms (AFLP) and simple sequence repeat (SSR) markers to analyze the phylogenetic relationships and genetic diversity among Secale species.; Phylogenetic analysis based on AFLPs showed that S. sylvestre had the most distant relationship to the other taxa. Annual forms were grouped together, but the perennial forms appeared more closely related to each other. This suggested that life cycle has played an important role in determining the relationships among Secale species. The AFLP analysis supported the classification of Secale into three species: S. sylvestre, S. montanum for perennial forms, and S. cereale for annual forms.; All Secale taxa successfully amplified 100% of rye and 75% of wheat (Triticum turgidum L.) SSR markers, except for S. sylvestre that amplified 84% of rye SSR markers. The phylogenetic relationships among Secale taxa based on SSR markers were in agreement with the AFLP results. Sequence analysis of five SSR markers among Secale taxa showed that marker SCM 101 exhibited high polymorphism in repeat length and flanking regions, which complicated assessing phylogenetic relationships. In contrast, markers SCM 65, 104, 273, and WMS 257 were more conserved. Those markers were more appropriate for analyzing relationships between Secale and other genera.; Cultivated rye exhibited a higher genetic diversity than weedy and wild rye, reflecting a diverse distribution of this group. The total genetic diversity of cultivated rye varied in each region. North American populations demonstrated the highest total genetic diversity, while East Asia showed the lowest. Phylogenetic analysis grouped 114 accessions of cultivated rye close to each other, excluding all weedy and wild rye populations. However, clustering of cultivated rye into strictly geographical origin groups did not appear.; We mapped 68 express sequence tags representing 26 genes into all seven homoeologous chromosome groups of wheat using a polymerase chain reaction technique. Comparative analysis between the EST map from this study and the EST map based on RFLPs showed that 79% of the genes that have been mapped by both approaches were mapped to the same locations, which indicated that using PCR-based ESTs was a reliable approach in mapping ESTs in hexaploid wheat. |
