05546 - Agricultural Genetics

Learning outcomes

At the end of the course the student will know and understand the basic mechanisms of trait inheritance, and the main tools to study and evaluate the genetic structure of natural and artificial plant communities.

Course contents

Contents of theoretical teaching unit (24 hours)

1) Developmental cycles in plants and animals. Structure of plant reproductive organs and apparatus. Mitosis and meiosis. The genetic material in a plant cell (2 hours)

2) Mendel's laws: genes and alleles, recessive and dominant alleles, segregations, assortment of traits and genes. Chi2 test. Extension of Mendel's laws: multiple alleles, incomplete dominance and co-dominance, gene interaction (epistasis), pleiotropy (4 hours).

3) The chromosomal theory of inheritance. Sex chromosomes. Cariotype. Monoecious and dioecious plants. Genetic determination of sex in crops. Cross incompatibility systems (2 hours)

4) Genetic linkage and frequency of recombination, centiMorgan, crossing-over, genetica maps (2 hours).

5) Biochemistry of nucleic acids: Watson and Crick DNA model, DNA replication, RNA transcription and splicing, translation and protein synthesis. Genetic code. Gene structure. Regulation of gene expression. The LAC operon. Central dogma of molecular biology (2 hours)

6) Genetics of quantitative traits, Johannsen's experiment, pure (inbred) lines, environmental and genetic causes of trait phenotypic variation, heritability. Experiments of Nilsson-Ehle and East. Multifactorial hypothesis for quantitative trait inheritance (2 hours)

7) Mutations at gene, chromosome and genome level (polyploidy and aneuploidy). Transposable elements. Mutagenesis. Origin of cultivated wheats (2 hours)

8) Introduction to population genetics. Hardy-Weinberg's principle. Evolution forces. Mechanisms of speciation. Inbreeding and heterosis (2 hours)

9) Introduction to genetic engineering for crop genetic imprevement. Main transformation methods (agrobacterium, biolistics). Main type of transgenes. Areas of GM crops cultivation (2 hours).

10) Genomics and molecular markers, type of markers, main applications for plant genetics and crop improvement. Introduction to marker-assisted selection (2 hours).

11) Introduction to plant breeding. Genetic systems and structure of crop species. Origin of cultivated specie and the domestication process (2 hours).

Contents of ‘practical activity' teaching unit (6 hours)

This teaching unit devotes to practical aspects of Mendelian, quantitative and molecular genetics.

Mendelian genetics (2 hours): the students will be presented with a simple statistical-genetic problem (eg. counting of gene frequencies in a simulated population, production of hypotheses explaining the observations, choice and application of appropriate statistical tests, test of the hypothesis). The written test will be carried out in classroom.

Quantitative genetics (2 hours): the students will be involved in collecting phenotypic measurements for quantitative traits (eg. plant height) in experimental plots available within the field adjacent to the DipSA building. Purpose of the activity is to make practical experience and evaluate environmental and genetic causes of phenotypic differences between individuals.

Molecular genetics (2 hours): the main molecular genetic techniques (eg. PCR, gel electrophoresis) will be briefly illustrated in classroom and during visits to the molecular genetics laboratory labs at DipSA.

Readings/Bibliography

Lorenzetti F, Ceccarelli S, Rosellini D, Veronesi F. Genetica Agraria (Fourth Edition, 2011). Patron Editore, Bologna.
Some aspects, following indications provided during the lectures, could be studied also on: G. Barcaccia, M. Falcinelli. Genetica e genomica, Vol I, Genetica generale. Liguori, Napoli, 2005.
Both books are in Italian.

Teaching methods

The course is divided in two teaching units. In the first one (frontal lectures) the main aspects of genetics of cultivated plants will be provided as detailed in the ‘content' section, for a total of 24 hours. The second teaching unit entails practical activities. It is divided in three lectures of 2 hours each, where the students will have the opportunity to experience the method of genetic investigation, to apply statistical-genetic test for hypothesis verification, to observe and quantify environmental and genetic causes of variation, to visit a molecular genetics lab.

Assessment methods

This course is included in the integrated course of ‘COLTURE ERBACEE E GENETICA AGRARIA' (662439) along with the course COLTURE ERBACEE (65915). Therefore, the evaluation of the student will include the knowledge acquired in both. For AGRICULTURAL GENETICS, the student preparation will be verified by oral examination. During the examination, three questions will be asked to the student. Two questions will relate to contents provided in the theoretical teaching unit and one question to the practical teaching unit and will concern about methodological and practical aspects of agricultural genetics. The oral examination lasts for about 30 minutes.

Teaching tools

All lectures will be given with the help of projected slides, in order to facilitate the explanation of the main concepts of the course, and in connection with the adopted text book.

Office hours

See the website of Silvio Salvi