Sweetpotato [Ipomoea batatas (L.) Lam] genetic incompatibility effects in true hybrids seeds for new farmer cultivars development

Abstract

Introduction: Sweetpotato is a vegetatively propagated, highly heterozygous and outcrossing crop. Genetic improvement of sweetpotato is complicated because of the hexaploid nature of the crop. The objective of this study was to assess genetic compatibility between sweetpotato accessions collected from Niger and Nigeria to select the best parents for the next hybridisation block to develop new farmer varieties. Materials and Methods: The experiment was conducted at field experiment of department of crop production and landscape management, Ebonyi State University, Abakaliki, Nigeria. The crossing block was established using diallel mating design method three to cross 13 genotypes. Results: Results revealed very highly significant difference (χ2 = 48.32; p < 0.001) for the successful cross rates. Complete incompatibility for both direct and reciprocal crosses was obtained from two crosses while, partial incompatibility was observed in 25 crosses (16.02%). Successful crosses rate varied from 14.82% to 43.58% with a grand mean of 28.04%. The mean of number of seeds per capsule between families ranged from 0.73% to 1.57% with a grand mean of 1.05. Germination rate varied from 22.92% to 75.90% with a grand mean of 45.91%. Conclusion: Clones AYT/19/05, TIS-81-64 and Umu SPO1 had high compatibility and they can be used as parents for the next crossing block.