Agronomy and Horticulture Department



Corn Breeding: Mass Selection

Date of this Version


Document Type



Plant and Soil Sciences eLibrary (PASSeL) Lesson


Copyright © 2019 Ken Russell and Leah Sandall. Used by permission.

This project was supported in part by the National Research Initiative Competitive Grants CAP project 2011-68002-30029 from the USDA National Institute of Food and Agriculture, administered by the University of California-Davis and by the National Science Foundation (NSF), Division of Undergraduate Education, National SMETE Digital Library Program, Award #0938034, administered by the University of Nebraska. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the USDA or NSF.


Objectives and Introduction

This is the fourth in a series of lessons specifically designed to instruct individuals without any formal training in genetics or statistics about the science of corn breeding. Individuals with formal training in genetics or statistics but without any training in plant breeding also may benefit from taking these lessons.

Mass selection could be called appropriately the granddaddy of all plant selection methods because farmers of many different cultures have used it for centuries to improve many crops. Specifically, mass selection is a breeding method where the decision to select a plant as a parent of the next generation is based on the performance of that plant. In this lesson, advantages and disadvantages of mass selection will be discussed, using examples from corn breeding.


At the completion of this lesson you will be able to

  • list the key attributes of mass selection,
  • discuss which type of traits are best suited to modification by mass selection,
  • use the formula known as the breeders’ equation to predict the genetic gain that occurs from mass selection,
  • define selection differential,
  • discuss how the selection differential can be increased and what problems can arise from increasing the selection differential, and
  • list four ways to minimize the amount of inbreeding that occurs during selection.