Evaluation of the Progenies from a Cross between Obiaoturugo and Adaka for Evidence of Segregation for Morphological Attributes and Resistance to Major Field Diseases of White Yam ( Dioscorea Rotundata Poir)

A field study was conducted at National Root Crops Research Institute Umudike Southeast Nigeria to determine evidence of morphological variation, traits that would contribute to tuber yield and response of the progenies to major field diseases. Data were collected on 60 sampled yam progenies out of the 150 progenies evaluated on morphological parameters such as leading vine length, vine diameter, length of leaf, width of leaf, number of leaves, number of lateral vines and severity of major diseases attacking yam cultivars in the field. Data obtained were subjected to statistical analysis using Genstat 5.32 package and Regression analysis was used to determine the morphological characters influencing the tuber yield of the progenies. The result obtained showed significant (P<0.01) variability in the morphological attributes exhibited by the progenies as a result of genetic reshuffling. This was observed in the range for the measurement of each of the morphological characters from minimum to maximum. Also, the variation in the responses of the yam progenies to biotic stresses indicated that there was genetic segregation responsible for the variations exhibited for most of the progenies. Some of the progenies were susceptible, tolerant and resistant to biotic stresses. Keyword: Progenies, A cross, Variation, Morphological characters and Major diseases