ISSN 2756-3847
International Journal of Plant Breeding and Genetics ISSN: 3167-5891 Vol. 3 (1), pp. 166-176, June, 2016. © International Scholars Journals
Full Length Research Paper
Combined use of parentage analysis and phenotypic assessment to evaluate the performances of cocoa (Theobroma cacao L.) varieties in farmers’ field
Olivier Sounigo1,2, Fidèle Nsouga2, Olivier Fouet3, Claire Lanaud3, Ives Bruno Efombagn Mousseni2*
1CIRAD, UR Bioagresseurs, BP 2572 Elig-Essono, Yaoundé, Cameroun.
2IRAD P0 Box 2123, Yaoundé, Cameroun.
3CIRAD, UMR AGAP, TA A108/3, Avenue Agropolis, 34398 Montpellier, France.
Corresponding author. E-mail: [email protected]
Accepted 19 June, 2016
Abstract
The genetic diversity of a cocoa population composed of 264 adult trees grown in anon farm plantation was assessed using 125 microsatellite markers to understand the relationship between the origin of the cultivated material and its agronomic features in the field. Analysis using a Bayesian model-based method allowed us to divide the cocoa trees into eight sub-populations (clusters) totaling 456 alleles with a coefficient of differentiation, FST = 0.1. Genealogical classes were generated within the entire population, and allowed to clearly identify 157 cocoa trees (59.46% of the total population) as derived from crosses between the two parental clones represented in bi-clonal seed-gardens, and were considered as true improved cocoa varieties while the genetic origin of 107 cocoa trees failed to be clearly identified. The parentage analysis carried out on the 157 trees identified as true F1-hybrids revealed that they belong to seven full-sib different progenies, derived from seven different bi-clonal seed-gardens. A comparison of the agronomical performances of three of the identified full-seed progenies showed differences for traits such as yield and susceptibility to pod rot caused by Phytophthora megakarya.
Keywords: Cacao, genetic structure, full-sib progenies, parentage analysis, morphological evaluation.