Genetic similarities among Iranian populations of Festuca, Lolium, Bromus and Agropyron using amplified fragments length polymorphism [AFLP] markers

The study of genetic variation and phylogenetic relationships is essential for the efficient selection of superior plant material and conducting introgression breeding programs. In Iran, despite the wide geographical distribution of grasses no report is available on the genetic diversity and relationships of cool season grass populations. In this study amplified fragment length polymorphism [AFLP] was used to study 42 populations from eight species of Festuca arundinacea Schereb., Festuca. pratensis Huds., Festuca. rubra L., Festuca. ovina L., Lolium perenne L., L. rigidum Gaud., Bromus tomentellus Boiss. and Agropyron cristatum [L] Gaertn. The number of amplified products ranged from 11 to 78 per primer combination and a total of 497 markers were scored. Jaccard's genetic similarity coefficients among populations ranged from 0.15 to 0.88 showing high levels of inter and intra-specific genetic diversity. The cluster analysis and principle coordinate analysis [PCOA] reflected the phylogenetic relationships among species and clearly demonstrated differences in the degree of similarity among accessions. Results indicated that AFLP is a useful technique to reveal genetic diversity at different taxonomic levels of grasses and might facilitate the selective introgression of useful genes in plant breeding programs

Water relations and leaf growth rate of three Agropyron genotypes under water stress

The effects of water stress on leaf water relations and growth are reported for three perennial tussock grass genotypes under glasshouse conditions. Studies were performed in genotypes El Palmar INTA and Selección Anguil of Agropyron scabrifolium (Dõell) Parodi, and El Vizcachero of A. elongatum (Host) Beauv. Agropyron scabrifolium El Palmar INTA is native to a region with warm-temperate and humid climate without a dry season, and an average annual precipitation of 900 mm. Agropyron scabrifolium Selección Anguil comes from a region with a sub-humid, dry to semiarid climate and a mean annual precipitation of 600 mm. Agropyron elongatum is a widespread forage in semiarid Argentina with well-known water stress resistance. A mild water stress treatment was imposed slowly; plants reached a minimum pre-dawn leaf water potential of about -1.83 MPa by day 21 after watering was withheld. In all genotypes, water stress led to a reduction of leaf growth. There was a tendency for a greater epicuticular wax accumulation on water-stressed plants of A. scabrifolium Selección Anguil and A. elongatum than on those of A. scabrifolium El Palmar INTA. This may have contributed to obtain greater turgor pressures and relative water contents in the first two than in the later genotype. In turn, this may have contributed to determine smaller leaf growth rate reductions in A. scabrifolium Selección Anguil and A. elongatum than in A. scabrifolium El Palmar INTA under water stress. This study demonstrated variation in water stress resistance between genotypes in A. scabrifolium, and between A. scabrifolium Selección Anguil and A. elongatum versus A. scabrifolium El Palmar INTA, which was related to their differential responses in water relations.