DNA, central dogma, Mendel’s experiments, and genetic association
The DNA is the hereditary material. The molecular structure of DNA. The organization of DNA in eukaryotic and prokaryotic cells. DNA replication. From DNA to proteins: transcription and translation.
Mendel experiments and the three Mendel’s laws. Extensions of Mendel’s laws.
Meiosis: the cellular basis of sexual reproduction. Mechanism of meiosis that generate genetic variability Comparison between meiosis and mitosis.
Genes and chromosomes: genetic association (linkage) and recombination, map distances.
Mechanisms of evolutionary changes
- What is a population?
- How to describe a population: genotypic and allelic frequencies.
- The Hardy-Weinberg law (HW), chi-square test, genetic diversity (HE) and divergence among populations (FST). Applications of the HW law. The role of the evolutionary forces on the level and structure of genetic variation in forest populations: mutations, genetic drift, migration, founder effect, bottleneck effect, effective population size (Ne), selection, recombination. Interaction between the evolutionary forces. Inbreeding: Inbreeding depression and heterosis.
- The genetic basis of quantitative traits.
- Mean, variance, standard deviation; covariance and correlation.
- Phenotypic value, genotypic value and environmental deviation. The model of Mather. Population mean, average effect of the alleles, average effect of allelic substitution, breeding value. Dominance deviations. The partitioning of the phenotypic variance: genetic variance (additive and dominance) and environmental variance. Genotype x environment interaction. Heritability (broad sense and narrow sense). Resemblance between relatives. Selection for quantitative traits: selection differential, intensity of selection, selection gain.
Factors influencing genetic variations within populations
Mating systems, population size, longevity, high levels of outcrossing, migration between populations (pollen and seed flow). Selection in changing environments: balancing selection. Plants density. patterns of cross-fertilization within populations. Spatial and temporal genetic structure within populations. Practical implications of the within-population genetic diversity: genetic improvements under natural regeneration systems. Seed collections in natural populations.
Provenance, clinal and ecotipic variation. Provenance x Environment Interaction. Experimental methods used to study geographic variation: short-term seedling tests, long-term provenance trials patterns of geographic variation in forest trees. Implications of geographic variation for Seed Transfer “Domestic” and “Darwinian” fitness. Seed-zones.
Relevance of the forest genetic resources. The in situ and ex situ strategies for the conservation of genetic resources. Sampling strategies. Core collections. The domestication of forest tree.
Phenotypic mass selection. Comparison between seedling forestry and clonal forestry. Clonal selection. Genetic gain, choice of traits and indirect response. General combining ability (GCA) and Specific Combining Ability (SCA). Progeny tests. Recurrent selection for GCA.
Biotecnology applied to forest tree improvement
Tree genomics resources. Structural and functional genomics. Population genomics. Association mapping studies (GWAS), markers assisted selection (MAS). Genomic selection, transgenesis, genome editing.