Importance of molecular cytogenetic markers in plant breeding

F.F. Cruz-Sánchez, E. Tapia-Campos, R. Barba-Gonzalez
Cytogenetics is the science that studies the structures and properties of chromosomes as well as their behavior during the division of somatic (mitosis) and germinal (meiosis) cells and their influence on the phenotype. Cytogenetics also studies the factors that cause chromosomal changes. New work in the area of molecular cytogenetic studies use probes to mark and identify a part of the chromosome and to obtain the karyotype of the cells of a species. Molecular cytogenetic markers are the set of techniques that are carried out through fluorescent labeling tests. Some of the techniques are fluorescent in situ hybridization (FISH), spectral karyotyping (SKY) and compartive genomic hybridization (CGH), which through different methodologies manage to obtain the characteristics of a chromosome. A probe is a fragment of DNA or RNA of small size that detects the presence of complementary sequences in the genetic material, these sequences can be similar or equal and for its visualization the probe is marked with a nucleotide that has some atom with radioactive isotopes or fluorochromes. The sequences that make up the probes are an important part for the identification of the chromosomes. Sequences of different individuals are used to define karyotypes, which help to identify chromosomal sections of species not studied and compare them with those that are already known. In plants, repetitive sequences have been used as probes, such as: wheat ribosomal DNA (18S-5.8S-26S rDNA (45S) and 5S rDNA), fragments of the RuBisCo gene of Polianthes tuberosa (RBCL), retrotrasposons, telomeric DNA sequences and centromeric for identification of the karyotype of species and hybrids and to improve the current classifications providing new information beyond observation of visible characteristics. In this work we present the molecular cytogenetic techniques used in the genetic improvement of plant species at CIATEJ.
Cruz-Sánchez, F.F., Tapia-Campos, E. and Barba-Gonzalez, R. (2020). Importance of molecular cytogenetic markers in plant breeding. Acta Hortic. 1288, 167-174
DOI: 10.17660/ActaHortic.2020.1288.25
chromosomes, fluorescent in situ hybridization, introgression

Acta Horticulturae