title: Maximum-likelihood method identifies meiotic restitution mechanism from heterozygosity transmission of centromeric loci: application in citrus.
abstract: Polyploidisation is a key source of diversification and speciation in plants. Most researchers consider sexual polyploidisation leading to unreduced gamete as its main origin. Unreduced gametes are useful in several crop breeding schemes. Their formation mechanism, i.e., First-Division Restitution (FDR) or Second-Division Restitution (SDR), greatly impacts the gametic and population structures and, therefore, the breeding efficiency. Previous methods to identify the underlying mechanism required the analysis of a large set of markers over large progeny. This work develops a new maximum-likelihood method to identify the unreduced gamete formation mechanism both at the population and individual levels using independent centromeric markers. Knowledge of marker-centromere distances greatly improves the statistical power of the comparison between the SDR and FDR hypotheses. Simulating data demonstrated the importance of selecting markers very close to the centromere to obtain significant conclusions at individual level. This new method was used to identify the meiotic restitution mechanism in nineteen mandarin genotypes used as female parents in triploid citrus breeding. SDR was identified for 85.3% of 543 triploid hybrids and FDR for 0.6%. No significant conclusions were obtained for 14.1% of the hybrids. At population level SDR was the predominant mechanisms for the 19 parental mandarins.
authors.affiliation: Crop Protection and Biotechnology Center. Instituto Valenciano de Investigaciones Agrarias (IVIA).
authors.forename: José
authors.initials: J
authors.lastname: Cuenca
authors.affiliation: Crop Protection and Biotechnology Center. Instituto Valenciano de Investigaciones Agrarias (IVIA).
authors.forename: Pablo
authors.initials: P
authors.lastname: Aleza
authors.affiliation: Crop Protection and Biotechnology Center. Instituto Valenciano de Investigaciones Agrarias (IVIA).
authors.forename: José
authors.initials: J
authors.lastname: Juárez
authors.affiliation: Crop Protection and Biotechnology Center. Instituto Valenciano de Investigaciones Agrarias (IVIA).
authors.forename: Andrés
authors.initials: A
authors.lastname: García-Lor
authors.affiliation: Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD).
authors.forename: Yann
authors.initials: Y
authors.lastname: Froelicher
authors.affiliation: Crop Protection and Biotechnology Center. Instituto Valenciano de Investigaciones Agrarias (IVIA).
authors.forename: Luis
authors.initials: L
authors.lastname: Navarro
authors.affiliation: 1] Crop Protection and Biotechnology Center. Instituto Valenciano de Investigaciones Agrarias (IVIA) [2] Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD).
authors.forename: Patrick
authors.initials: P
authors.lastname: Ollitrault
mesh_terms: D000483:Alleles; D002503:Centromere / Q000235:genetics*; D032461:Chromosomes, Plant; D002957:Citrus / Q000235:genetics* / Q000254:growth & development; D003433:Crosses, Genetic; D005838:Genotype; D055993:Germ Cells, Plant; D006579:Heterozygote; D016013:Likelihood Functions; D008540:Meiosis; D000069600:Plant Breeding; D011123:Polyploidy