Glossary used in the plant breeding world

Did you know that nowadays, all major crops are available only because of plant breeding?

Plant breeding is nearly as old as human civilizations. Humans have had a significant impact on plant evolution. They began choosing and spreading seeds from plants that looked, smelled, and tasted well while also producing an appropriate yield. This selection resulted in the first domesticated food crops, and it is still at the heart of modern plant breeding today.

When compared to a few decades ago, plant breeding has advanced dramatically. Furthermore, plant breeding employs a wide range of scientific disciplines and sophisticated technologies, making it difficult for beginners to grasp.

We do not want to spook you; on the contrary, we want to pave your way into the arts and science of plant breeding.

Let us dive in today into the most common terms used when people talk about plant breeding.

Plant breeding and genetics

Plant breeding is a science that focuses on developing new varieties. It can go from selecting plants with desirable characteristics to specialized methods that make use of genetics to predict the outcomes.  Plant breeding involves the use of the available genetic resources (the valuable genetic material of plants) for improving the existing traits (specific measurable characteristics such as, plant height, yield, flower color and so on).

We cannot talk about plant breeding unless we understand genetics. Genetics studies genes and heredity.

Genes are portions of DNA (hereditary material) that hold information for the construction of molecules that help organisms function. These genes are handed on from a parent to their offspring through a process known as inheritance.

Due to inheritance, we share some characteristics with our parents and siblings. Each gene is passed down to offspring in two copies, one from the mother and one from the father. These variations are referred to as 'alleles’. If both inherited alleles are the same, the offspring is said to be 'homozygous’, but if both inherited alleles are different, the organism is said to be 'heterozygous’.

The information held in an organism's collection of genes is known as its 'genotype’, and it differs for each offspring. However, the way those genes exhibit themselves in any creature — such as height, mass, color, and flavor — is referred to as the ‘phenotype’.

Now that we have established the connection between plant breeding and genetics, let us go over the most commonly used glossary in plant breeding research.

Plant breeding glossary

Population: A group of related individuals that share a ‘gene pool’ (that is, all the genetic information available from all the genes)

Genotype: The gene set of a specific individual. The process of characterizing the genotype is known as ‘genotyping’.

Also, a specific individual from a population is called a genotype.

Phenotype: This is the visual expression of genes such as color, shape, flavor, etc. This is the result of the genotype influenced by the environment.

Variety: A recognizable individual within a species due to its outstanding traits of human interest.  Plants of the same genotype must be distinct, uniform, and stable in order to be termed a variety.

Hybrid: A plant that is the product of crossing or sexually reproducing parents with diverse genes.

Genetic distance: This is a metric used to evaluate how genetically distant one individual is from another, or how closely related two individuals are. The metric begins at zero for closely related individuals and grows as the genetic distance between them increases. The genetic distance between two species or populations of any species can also be measured.

Inbreeding: The result of crossing related individuals to produce highly homozygous ‘inbred’ or ‘pure lines’ (whereby, almost all pairs of alleles are equal). The only way of producing 100% homozygous plants is by creating double haploids.

Hybrid vigor: The improvement of vigor, survival, and fertility of a hybrid produced by crossing genetically distant individuals. It is also known as ‘heterosis’.

Inbreeding depression: The loss of vigor of a resulting offspring from the cross of very close relatives. The opposite of hybrid vigor. Plants are weaker than their parents.

Self-pollination: Pollinate a plant with its pollen grains. This technique is often used by breeders to increase the genetic similarity of individuals to generate pure lines.

Open-pollinated populations: Population pollinated without the interference of breeders (following the natural course). Usually, this population is used to sample the genetic diversity of the genetic pool.

Germplasm collection/plant genetic resources: The gene set available in a population for breeding. By using this gene set, breeders can express any given phenotypic combination.

Plant breeding is a fascinating aspect of plant science with its own unique characteristics. If you were unfamiliar with plant breeding before reading this article, maybe you now grasp some of the popular terms.

We hope you found this post interesting. Keep an eye on this space for more intriguing articles about plant breeding facilities and businesses! 

By Nataly Sánchez Del Río | 4th October 2022

References:

• Miko, I. (2008) Gregor Mendel and the principles of inheritance. Nature Education 1(1):134
• Maloy, S. R., Hughes, K. T., & Brenner, S. (2013). Brenner's Encyclopedia of Genetics. Elsevier/Academic Press.
• Singh, D. P., Singh, A. K., & Singh, A. (2021). Plant breeding and cultivar development. Academic Press.
• Schlegel, R. H. (2020). Dictionary of plant breeding (3rd. ed.). CRC Press.
• Brown, J., Caligari, P. D. S., & Campos, H. A. (2014). Plant breeding (2nd ed.). Wiley and sons.