Abstract

Aerial yam (Dioscorea bulbifera L.) is an underutilized crop of significant economic importance and a potential contributor to food security in developing countries. Understanding its genetic diversity is crucial for effective breeding and crop improvement. A two-year field experiment was conducted at the National Root Crops Research Institute (NRCRI), Umudike, Nigeria, using 94 aerial yam accessions sourced from the National Root Crops Research Institute (NRCRI), Umudike and the International Institute of Tropical Agriculture (IITA), Ibadan. The study aimed to characterize and assess the extent of genetic diversity among these accessions based on phenotypic traits. The accessions were evaluated in a randomized complete block design (RCBD) with three replications. Data on morphological and agronomic traits, including bulbil yield, were collected and pooled across the two years. Frequency distributions for qualitative traits revealed substantial variation in stem colour, leaf colour, leaf type, bulbil shape, and bulbil skin texture. Combined analysis of variance showed highly significant genotypic differences (p < 0.001) for most traits. Principal component analysis identified four components with eigenvalues >1, explaining 52.9% of total variation. The first component (34.5%) was associated with vine length, number of branches, stem count, and total bulbils per plot, while the second was strongly linked to bulbil weight and yield. The FAI-BLUP index effectively identified superior genotypes, with accessions YC2, YBI, YB5, YD4, YA5, YA3, YB4, YA1, and YC3 emerging as promising candidates for simultaneous improvement of key agronomic traits in D. bulbifera breeding programs.