Assessment of Genetic Variability Estimates of Selected Traits in Irish Potato Mutants
Emmy Chepkoech *
School of Agriculture and Biotechnology, University of Eldoret, P.O. Box 1125-30100 Eldoret, Kenya.
Miriam G. Kinyua
School of Agriculture and Biotechnology, University of Eldoret, P.O. Box 1125-30100 Eldoret, Kenya.
Oliver Kiplagat
School of Agriculture and Biotechnology, University of Eldoret, P.O. Box 1125-30100 Eldoret, Kenya.
Julius Ochuodho
School of Agriculture and Biotechnology, University of Eldoret, P.O. Box 1125-30100 Eldoret, Kenya.
Stephen Kimno
School of Agriculture and Biotechnology, University of Eldoret, P.O. Box 1125-30100 Eldoret, Kenya.
Leah Boit
School of Agriculture and Biotechnology, University of Eldoret, P.O. Box 1125-30100 Eldoret, Kenya.
*Author to whom correspondence should be addressed.
Abstract
Aims: For an effective potato breeding strategy, knowledge of the genetic parameters of traits, such as heritabilities and genetic correlations are essential, hence the need to assess the genetic variability estimates of yield-related traits in Irish potato mutants
Study Design: At M1V1 generation, there was no replication of the mutant minitubers because each does not maintain the same genetical constitution after irradiation. In M1V2 and M1V3 generation the tubers were replicated 3 times in alpha lattice design.
Place and Duration of Study: Irradiation was done at the Plant Genetics and Breeding Laboratories (PGBL) at IAEA/FAO Seibersdorf, Vienna, Austria. After mutation induction, the mutant microtubers (consisting of Asante, Mpya and Sherekea) were was transported to Kenya, University of Eldoret for establishment between April 2015 and March 2017.
Methodology: A total of 30 tubers each of the three potatoes was sent for irradiation. Two in-vitro radio-sensitivity tests were developed involving different tissues: Irradiation of in vitro nodal cuttings (without leaf) followed by in vitro shoot propagation and irradiation of in vitro nodal cuttings (with leaf) followed by direct in vitro micro-tuber production. After mutation induction, a total of 570 mutant microtubers (Asante 230, Mpya 160, Sherekea 180) were developed from the three potato varieties and was transported to Kenya, University of Eldoret for the establishment. The M1V1 microtubers were established in the greenhouse while M1V2 and M1V3 generations of mutants were planted at the at the University of Eldoret research field.
Results: It showed that the highest positive heritability percentage (H2) estimates in Mpya and Sherekea mutants were in plant height with 81.51% and 87.7% respectively.
Conclusion: Tuber number exhibited high heritability estimates displaying that induced mutation was successful in the development of new potato genotypes which be used in future breeding programs.
Keywords: Potato, mutants, irradiation, variability, heritability, microtubers.