Breeding & Genetics

Overview

Plant breeding is the art and science of changing the traits of plants in order to produce desired characteristics. Plant breeding can be accomplished through many different techniques ranging from simply selecting plants with desirable characteristics for propagation, to more complex molecular techniques.

Plant breeding started with sedentary agriculture and particularly the domestication of the first agricultural plants, a practice which is estimated to date back 9,000 to 11,000 years. Initially early farmers simply selected food plants with particular desirable characteristics, and employed these as progenitors for subsequent generations, resulting in an accumulation of valuable traits over time. Gregor Mendel's experiments with plant hybridization led to his establishing laws of inheritance. Once this work became well known, it formed the basis of the new science of genetics, which stimulated research by many plant scientists dedicated to improving crop production through plant breeding. Modern plant breeding is applied genetics, but its scientific basis is broader, covering molecular biology, cytology, systematics, physiology, pathology, entomology, chemistry, and statistics (biometrics).

Classical Breeding

Classical plant breeding uses deliberate interbreeding (crossing) of closely or distantly related individuals to produce new crop varieties or lines with desirable properties. Plants are crossbred to introduce traits/genes from one variety or line into a new genetic background. For example, a mildew-resistant pea may be crossed with a high-yielding but susceptible pea, the goal of the cross being to introduce mildew resistance without losing the high-yield characteristics. Progeny from the cross would then be crossed with the high-yielding parent to ensure that the progeny were most like the high-yielding parent, (backcrossing). The progeny from that cross would then be tested for yield and mildew resistance and high-yielding resistant plants would be further developed. Plants may also be crossed with themselves to produce inbred varieties for breeding. Classical breeding relies largely on homologous recombination between chromosomes to generate genetic diversity. The classical plant breeder may also make use of a number of in vitro techniques such as protoplast fusion, embryo rescue or mutagenesis (see below) to generate diversity and produce hybrid plants that would not exist in nature.

Traits that breeders have tried to incorporate into crop plants in the last 100 years include:

  • Increased quality and yield of the crop
  • Increased tolerance of environmental pressures (salinity, extreme temperature, drought)
  • Resistance to viruses, fungi and bacteria
  • Increased tolerance to insect pests
  • Increased tolerance of herbicides
Projects
2015 to 2019
Development of improved lentil cultivars well-adapted to the local environment is an on-going process in the breeding program and is critical for long-term genetic gain. Recent climate instability adds another layer of complexity to breeding efforts. Continued genetic improvement of lentil will, therefore, involve the introduction of new alleles that extend beyond the existing adapted pool of germplasm. Our goal in AGILE is to enhance the productivity and quality of Canadian lentils by expediting the expansion of genetic diversity of the Canadian lentil germplasm base with the use of genomic technologies.
2016 to 2018
<p>A diverse collection of lentil accessions is being phenotyped for days to flower and screened against potential flowering time genes Identified by other researcher groups. In addition to the confirmation and the development of markers useful for the prediction of flowering time in northern temperate (Sask.) conditions, the identification of other candidate flowering time genes are goals of this project.</p>
2015 to 2017
Stone seeds, which are seeds that do not absorb water, are considered a negative seed quality characteristic because they need to be removed before commercial processing. A high physical dormancy at the end of seed development is found to be the cause of this issue, but it is not known how or when it develops. This project will focus on attempting to determine when the seeds begin to develop physical dormancy, and also how to avoid hard seededness through harvest times.
2017
An Illumina Golden Gate array was developed using SNPs identified as part of the Common Bean 454 Sequencing & Genotyping Project.
2014 to 2017
This is an international project funded by the Global Crop Diversity Trust aimed at evaluating cultivated x wild lentil introgression lines for multiple traits in multiple environments.
2013 to 2016
As production of the dry bean is moving towards short season growing regions such as Alberta and Saskatchewan, it is becoming increasingly important to find a way to develop abiotic stress tolerances for the dry bean. Through the incorporation of genes from other species, the stress tolerance capabilities of the dry bean will increase, making it less sensitive to its surrounding climate. The tepary bean was decided upon as the best genetic donor for improvement to the dry bean, and is now being evaluated in Saskatchewan and its international partners.
2013 to 2016
Our approach to sequencing the lentil genome is two-fold. First, we are generating a high quality draft genome for a single lentil genotype (CDC Redberry), including bulk sequencing, assembly of chromosomal ‘pseudomolecules’, and gene prediction and annotation. Secondly, we are re-sequencing various lentil accessions from around the globe to reveal the breath of genetic potential present in our germplasm resources. The outcome will give us i) an understanding of how modern breeding has re-shaped the lentil genome, ii) identification of genes and genomic interval that control agronomic traits, and iii) discovery of many genetic polymorphisms for future marker development, that together will add considerable resources to the breeder’s toolbox for lentil genetic improvement. More importantly, the results of this project will allow us to leverage knowledge of important trait based on conservation of genome-based features with other legume crops (such as Medicago and chickpea).
2013 to 2016
Lentils are seen as a source for essential vitamins and minerals for human nutrition, but due to the high anti-nutritional factors of raffinose family oligosaccharides the consumption of lentils are being limited. Other methods to lower the levels of these RFOs are costly, and that is why an alternative strategy to develop varieties of lentil with lower levels is being implemented.
2013 to 2015
The objectives of this study are to determine the effect of genotype and environment on iron bioavailability in a set of five pea varieties differing in phytate concentration using the Caco-2 mammalian cell bioassay, to determine whether iron bioavailability in field pea is heritable by evaluating recombinant inbred lines differing in phytate concentration using the Caco-2 mammalian cell bioassay, and to determine the effect of the pea low phytate trait on chicken performance and iron bioavailability in chicken.

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