05546 - Agricultural Genetics

Learning outcomes

The student will receive the knowledge and methodology to understand the mechanisms that regulate the genetic inheritance of traits in plants and animals and the associated molecular tools that have been / are being developed and used to evaluate and manipulate the genetic structure and diversity of natural and artificial plant populations

Course contents

Summary program:

-Cell biology, haploid-diploid developmental cycle, mitosis, meiosis. Recombination

- Chromosome, nuclear, chromatin structure, DNA structure, composition, DNA replication model, Gene structure in eucariotes. Gene space, intergenic regions, Repeated fraction of the genome. Transposons and retrotransposons

- DNA and RNA, gene structure, gene expression,transcription, translation. Gene expression regulation (several levels) Transcription factors

- Mutations: types, molecular basis, Point mutations, IN/DEL. Mutations: at gene and chromosomal level. Mutagenesis: why and how. Chemical and physical mutagenesis. Forward and reverse genetic mutagenesis

- Polyploidy: auto- and allo-polyploidy. Mechanisms. Importance and diffusion. Wheat and brassica as main examples

- Mendelian genetics. Theory and practical exercises. Chi2 test. Simple trait inheritance. The three Mendelian laws

- Sex determination. Asparagus example

- Dominance, semidominance, codominance. Different meaning in authogamous and allogamous species. Genetic load in allogamous plants and purifying selection in authogamous plants. Allard examples (oat)

- Gene interaction: epistasis and pleiotropy. Multiple alleles: self-incompatibility and disease resistance gene examples

- Gene association, crossing over, recombination, genetic linkage maps, physical maps

- Molecular markers,types RFLP, SSR, SNP, IN/DEL. Shift from genic markers to molecular markers. Use of molecular markers in linkage mapping,association mapping in natural populations. Haplotypes.

PCR, gene sequencing, gene isolation, estimates of genetic relationships / genetic distances, next-generation sequencing, Genomics databases

Gene-based haplotypes at causal genes and molecular markers' haplotypes in close neighbor regions. Molecular markers diagnostic haplotypes

- genetic basis of sex-determination in plants, self-incompatibility

- quantitative genetics, multifactorial genetic basis of complex traits. Normal distribution. QTL. L-shape distribution of QTL effects. Robertson' hypothesis and unfication of the Mendelian and quantitative genetics.

- Heterosis: definition, practical use in breeding

population genetics. Gene and Genotypic allelic frequencies, Hardy-Weinberg equilibrium. Mutation, migration and genetic drift effects, Gene flow. Evolutionary model for isolated populations.

- population structure. How to evaluate it based on the use of molecular markers

- domestication. Common mechanisms.  Gene and traits involved in the domestication process. Example in Triticum, domestication + polyploidy

- Basis of genetic improvement for authogamous and allogamous plants. Marker-assisted selection

- Genetic engineering. Genetic transformation basis. Genome editing, New Breeding Technologies

Readings/Bibliography

Genetica Agraria (Lorenzetti, Ceccarelli, Rosellini, Veronesi) , Patron editore, 4a edizione, 2011.

Genetica Agraria (Russell, Wolfe, Hertz, Starr, McMillan), EdiSES editore, 2016.

Genetica e Genomica Vol. 1, Barcaccia e Falcinelli, Liguori Ed.

Genetica e Genomica Vol. 2, Barcaccia e Falcinelli, Liguori Ed.

iGenetica Fondamenti, Peter J Russell, Edizione italiana a cura di Bellenchi, Gigliani, Ponti, EdiSES srl, Napoli

Teaching methods

The basis of the course is provided by direct lessons based on power-point presentations.

As a complement we will add two training days in the molecular marker lab plus two days in the field in order to get exposed to a range of molecular techniques for the lab and plant materials representing different steps of domestication and genetic improvement of wheat are provided in the Faculty Garden

 

Assessment methods

The exam is based on an oral exams of 25-30 minutes with three questions related to the program, of incremental challenge. Further discussion on specific topics, connections among topics, application of the scientific knowledge will complete the exam.

Teaching tools

power-point slides, discussion of scientific manuscripts, direct observations in the molecular lab, botanic garden, field

Office hours

See the website of Marco Maccaferri