Assessment of the Phenotypic Diversity of Sweet Potato Landraces (Ipomoea batatas L.) Cultivated in Benin Using Morphological Descriptors

Aim: Ipomoea batatas is one of the tuberous roots produced in Benin for its nutritional and economic interests and whose diversity remains unknown. This research work aims to evaluate the phenotypic variability within sixty-four landraces collected in South and Central Benin.

Methodology: The trials were carried out using randomised complete block design with three replicates at the experimental site of Agricultural School of Akodeha at southern part, of Benin during two consecutive rainy seasons, September to November 2016 and May to July 2017. Nineteen (19) qualitative and six (6) quantitative traits selected from the descriptors of the International Potato Center were used. An ascending hierarchical classification based on the discriminant variables was carried out.

Results: The results obtained showed the existence of a morphological diversity within the collection studied for the principal color of the stem, the pubescence of the top of the stem, the general appearance of the leaf, the pigmentation of the abaxial vein of the stem, the leaf, the predominant color of the skin of the tubers, the secondary color of the flesh of the tubers and its distribution. The landraces were grouped into seven (7) classes with qualitative variables. Similarly, with the quantitative variables, 7 groups were obtained.

Conclusion: The information from this study provides a useful database for moving towards molecular genetic characterisation of sweet potato landraces in Benin and for their in vitro and ex situ conservation for breeding programs.