Genetic parameters, prediction, and selection in a white Guinea yam early-generation breeding population using pedigree information
Citation
Asfaw, A., Aderonmu, D.S., Darkwa, K., De Koeyer, D., Agre, P., Abe, A., Olasanmi, B., Adebola, P., Asiedu, R. (2021). Genetic parameters, prediction, and selection in a white Guinea yam early-generation breeding population using pedigree information. Crop Science, [online] 61(2), 1038-1051. http://dx.doi.org/10.1002/csc2.20382
Plain language summary
This study aimed to assess genetic parameters accounting for additive and dominance effects in prediction for six essential traits in white Guinea yam breeding populations using pedigree information. Eighty-three full‐sib families represented by 1,420 progenies were evaluated at 2 sites in Nigeria. Data were subjected to different analyses to assess population structure, to estimate the relative genetic variability, as well as to predict the genetic values of parents and their progenies in the breeding population. Significant non-additive genetic variances were found for yam traits. The pedigree analyses used in this study is relevant for selection of parents and progenies in yam breeding. Multiple‐trait selection indices have potential for identifying superior breeding lines. Model fit and prediction accuracy of breeding value vary with genetic effects and traits. Overall, this study has provided valuable insights into the genetic control and genetic gain, as well as a glimpse of the status of the six essential traits in the white Guinea yam breeding program. The superior clones having higher genotypic values identified through the multi‐trait selection index will be tested further for possible commercial deployment.
Abstract
Better understanding of the genetic control of traits in breeding populations is crucial for the selection of superior varieties and parents. This study aimed to assess genetic parameters and breeding values for six essential traits in a white Guinea yam (Dioscorea rotundata Poir.) breeding population. For this, pedigree-based best linear unbiased prediction (P-BLUP) was used. The results revealed significant nonadditive genetic variances and medium to high (.45–.79) broad-sense heritability estimates for the traits studied. The pattern of associations among the genetic values of the traits suggests that selection based on a multiple-trait selection index has potential for identifying superior breeding lines. Parental breeding values predicted using progeny performance identified 13 clones with high genetic potential for simultaneous improvement of the measured traits in the yam breeding program. Subsets of progeny were identified for intermating or further variety testing based on additive genetic and total genetic values. Selection of the top 5% progenies based on the multi-trait index revealed positive genetic gains for fresh tuber yield (t ha−1), tuber yield (kg plant−1), and average tuber weight (kg). However, genetic gain was negative for tuber dry matter content and Yam mosaic virus resistance in comparison with standard varieties. Our results show the relevance of P-BLUP for the selection of superior parental clones and progenies with higher breeding values for interbreeding and higher genotypic value for variety development in yam.