Genetic diversity and adaptation to different tillage and farming systems of cocoyam genotypes (Xanthosoma sagittifolium L. Schott) in the Eastern Region of Ghana

Experiments conducted in Ghana show that cocoyam exists as mixtures of clones in farmers farms. This work aimed to use RAPD markers to determine the extent of diversity in cocoyam genotypes collected from farms at different locations in the Eastern region of Ghana. The study also investigated whether the genotypes have different adaptation to different farming systems (intercropping with plantain and sole cropping) and tillage methods (mounds and flat). The genotypes were grouped into two main clusters at 0.65 similarity coefficient of variation with accessions Pameng Red 3 and Pramkese 2 being the most diverse. The genotypes began separating at 85% similarity index into three discrete groups. Group I, (Pameng 1, Dwenase 2 and 3) did not separate at 100% similarity index. The other two groups consisted of (Pameng 2, Gyampomani 1, Gyampomani 2, Dwenase 1) and (Pramkesse 1 and Gyampomani 3). The analysis of variance of the growth parameters of the genotypes under the tillage and farming systems revealed significant differences. Generally, genotypes in group II grew better under the farming systems and tillage practices studied whiles Pramkesse 2, which did not cluster with any other genotypes in its major cluster, grew poorly under the two farming systems.   Key words: Cocoyam, intercropping, solecropping, mounds, flat, RAPDS.