AGRON 521 – Principles of Cultivar Development – Each Spring

(3-0) Cr. 3. Prereq: AGRON 421; STAT 401

Office: 1501 Agronomy hall

Learning outcomes:

  • Students will be able to set plant breeding objectives, acquire germplasm and use it to develop cultivars, create and utilize genetic variability, and make selections to develop cultivars.
  • Students will be able to make decisions on the types of populations to develop, breeding schemes to implement, tools and techniques to utilize to enhance genetic gain in allocated resources.

Learning objectives:

Core Categories – Core Concepts – Learning Objectives

1. Basic concepts in cultivar development

  • Define mating systems
  • Recognize similarities and dissimilarities between populations and cultivars
  • Identify and infer types of cultivars
  • Review and explain crossing symbols, pedigree writing and selection history
  • Define breeding process and breeding objectives in major crops
  • Describe the principles of setting breeding objectives
  • Application of knowledge of breeding objectives in cultivar development

2. Germplasm usage in cultivar development

  • Summarize natural and artificial selection
  • Illustrate plant breeding pipeline
  • Describe sources of parental material and principles in assembling genetic variation
  • Compare various mechanisms of variety protection
  • Revise material transfer agreements and germplasm sharing, and associated legal issues

3. Review of basic population and quantitative genetics principles

  • Understand the different types of populations in plant breeding
  • Apply different types of crossing schemes for cultivar development
  • Learn to distinguish qualitative versus quantitative traits and apply in cultivar development pipeline
  • Understand the concepts of variability, phenotype, genotype, and genotype x environment (G x E) interactions
  • Identification of high yielding stable varieties
  • Understand the concept of heritability and practice selection
  • Learn selection theory and deploy for increased response to selection (breeder’s equation)
  • Recognize multiple trait selection scenarios and deploy for different scenarios
  • Understand mating designs, combining ability and its calculations
  • Explain heterosis
  • Choose program size, generation to select and population sizes

4. Steps in cultivar development and breeding methods

  • Operate field testing program with choice of statistical design and analysis for breeding trials
  • Deploy principles of cultivar development to create new varieties
  • Describe main steps in development of pureline, clonal, synthetic, hybrid, multi-line and blend cultivars
  • Understand and deploy strategies for population improvement
  • Select appropriate tools (phenomic, genomic, infrastructural) for achieving program objectives
  • Describe main breeding and selection methods in cultivar development (generation advancement, selections, pre-commercial testing, seed production and certification, distribution)
  • Evaluate cultivar development pipelines for different types of cultivars in major and minor crops

5. Building and operating a cultivar development program

  • Learn Resource management
  • Select appropriate tools for testing and selection of genetic material
  • Evaluate success and deficiencies (and remedy) in the program
  • Understand and utilize multi-disciplinary approaches to achieve program objectives

Course format:

Lectures (with classroom discussion), group activities, research projects.


Basic Concepts

Major crops and breeding objectives, setting breeding objectives, reproductive systems, populations and cultivars, types of cultivars, crossing symbols, pedigree writing, selection history, generation writing conventions.

Genetic variation and germplasm usage

Natural vs Artificial selection, overview of plant breeding process, cultivar develop phases, centers of diversity, gene bank, types of variability, germplasm resources, wide hybridization, creating breeding populations, MTA, parental selection.

Primer on population and quantitative genetics

Types of populations, population sizes, qualitative and quantitative traits, gene action, concept of phenotype genotype, environment, heritability, selection theory, genetic gain, variability in response to selection, multiple trait selection, Genotype x Environment interaction; combining ability, heterosis.

Basic steps in cultivar development

Steps in the development of cultivars: clonal, purelines, inbreds, synthetics, hybrids, blends.

Breeding methods and their modifications

Bulk method, Pedigree method, Single Seed Descent, Doubled Haploid, Backcrossing, Intra-population and inter-population recurrent selection.

Use of tools in plant breeding

Doubled haploid, winter nurseries, marker assisted selection, genomic prediction and selection, high throughput phenotyping and phenomics assisted breeding.

Methods in cultivar development

Clonal; Self-pollinated; Cross-pollinated crops.

Practical examples of cultivar development

Set objectives, use data to make selections, use appropriate tools, generation advancement and selections; adaptation/pre-commercial testing; seed multiplication and distribution

AGRON 522 – Field Methods in Plant Breeding – Alternate Summer Semester

Cr. 2. Prereq: AGRON 521, or instructor’s permission

Office: 1501 Agronomy hall

Course details: Weekly three hour sessions with a mix of site visits and informal lectures. Visits and interactions include:

  • agricultural equipment manufacturers
  • precision agriculture manufacturers
  • hand’s on activities and lecture related to plant transformation
  • hand’s on activities and lecture related to molecular markers and doubled haploid
  • visits to major seed companies
  • participation in breeding activities of maize, soybean, forages, sorghum and clonal crops
  • germplasm bank
  • seed production and certification