Genetic characterization of two Eragrostis species using AFLP and morphological traits

Tef [Eragrostis tef (Zucc.) Trotter] is the most important cereal crop in Ethiopia. An experiment was conducted to investigate genetic diversity among four cultivars of tef and 14 accessions of Eragrostis pilosa using radiolabelled and silver stained amplified fragment length polymorphism. Morphological traits were also evaluated. A total of 897 markers were obtained out of which 395 were polymorphic using 11 primer combinations. Cluster analysis revealed accessions of E. pilosa which are distantly related and others closely related to tef. Our previous experience also indicates that E. pilosa is crossable with tef. Those accessions distantly related to tef could be used in a crossing program to generate a population for selection and/or genetic mapping. Such genetic mapping populations will form an important entry point towards the molecular genetic dissection of the plant genus, Eragrostis, especially in the context of comparative mapping. Knowledge gained from such study, apart from tef improvement, will also be useful for many forage and turf grass species where little molecular genetic information is available. Nine cultivars or accessions had one or more unique fragments using one or more AFLP primers indicating the potential of the technology in fingerprinting tef in a breeding or seed multiplication program. The results also showed that clusters obtained using silver staining and gamma 33P-ATP labeling were similar, suggesting that silver staining could be used as an alternative to radiolabeling at least in genetic diversity analysis. Significant genetic variation was obtained for morphological traits. Of particular interest to tef breeding was short plant stature in E. pilosa which could be transferred to tef to minimize the problem of lodging. Diversity revealed at the morphological trait level was not commensurate with that observed for AFLP. This was due to the small number of available morphological traits and their interaction with the environment.