Variation in morphological characters in a collection of yams (Dioscorea spp.)

摘要

Morphological characterization and preliminary evaluation was conducted on the NPGRL yam collection considering 113 descriptors. Three hundred twenty six accessions were completely characterized for two planting seasons. Character frequencies were made and species description presented. Results indicated highest variation among leaf and tuber forms of D. alata followed by D. esculenta and D. hispida. The number of D. alata with purple tuber flesh color is less than those accessions with white or off-white flesh. Spine characters were found more variable on D. hispida than D. esculenta. A summary list of accessions with particular character states was given. Identification of species D. bulbifera and a probable representa five of D. divaricata or D. nummularia were given. Further characterization to delineate among varietal groups in D. bulbifera, D. esculenta and D. hispida as well as other studies were suggested to be done in the future.