Inbreeding is a path towards homogeneity to develop a pure date palm varieties: A review

The extent of the reduction in the percentage of hybrid or heterozygous genotypes can be measured by the inbreeding coefficient. The percentage of hybrid decreases 12.5% when mating half-siblings and 50% when mating full-siblings after 3-4 generations of inbreeding. Inbreeding increases genetic homogeneity and stabilizes desired traits when the quality factor is present in closely related or semi-dissimilar families within a lineage that contains the traits of the parent. Once a lineage of a purebred parent is obtained, all the effort and years of work spent on annual seed propagation are minimized. The appearance of phenotypic and fruit traits different from the parent is likely due to the association of one of the genes or factors responsible for the targeted trait with an unknown gene. Pure genetic traits are transmitted from parents to seedling with a high degree of accuracy. Values close to zero indicate random mating. Large positive values indicate inbreeding or undetected dormant alleles. Negative values indicate high mixing between the parents inheriting the trait, resulting from negative selective mating or natural selection. Therefore, the initial evaluation of palm seedling in their early growth stages, the adoption of phenotypic characterization, molecular markers and identification of the type factor are important. Determining the type and effect of some linked dominant alleles is also essential for palm tree breeding programs.