3.1 Introduction
Plant breeders enjoy quoting a famous US president, who wrote that “The greatest service
which can be rendered any country is, to add an useful plant to its culture.”^1 Whether or not
you agree, it must be acknowledged that the creation of new and better plant varieties is
among the most useful and visible outcomes of biotechnology. Whether it is a noble
service might depend on whether you do it for fun, for profit, or for the good of humanity,
but most breeders will confess to all three motives. Plant breeding has been credited with
helping to triple the productivity of modern agriculture, and it has been a fundamental part
of international humanitarian achievements (Hoisington et al. 1999). But you do not have to
“think big” to be excited about plant breeding. Admire the colors on your next plate of food,
taste the subtle flavors in your next bite of fruit, feel the strength and softness of your cotton
shirt, or smell your favorite rose—these characteristics are all derived from unique charac-
ters of different plant varieties. You spend less of your income to eat a much better variety
of foods than your ancestors did, largely because of plant breeding. In future you might
live longer or healthier because of the varieties of plants used to make your breakfast
cereal. What fun it would be to create those varieties, or even just to understand how
they are created!
Plant breeding is a skill that requires advanced learning and practical experience. Many
universities and corporations worry that trained plant breeders are becoming scarce in
relation to ongoing demands. Most of the modern concepts in biotechnology that are intro-
duced in this book can be viewed either as enhancements to plant breeding, or as inno-
vations that can be rendered useful only through plant breeding. The most
groundbreaking achievements in biotechnology still need to be packaged in plants that
are productive, disease-free, tasty, and nutritious. These qualities depend on the coordinated
expression and complex interactions of thousands of plant genes and gene products. We
have learned many things about many genes, but we may never know enough to fine-
tune all of the genes required to make a plant variety that is adapted and competitive
under modern agricultural production practices. Thus, we continue to depend on plant
breeding as the cornerstone of commercialization and technology transfer.
Plant breeding was described by Nikolai Vavilov,^2 the famous Russian scientist, as
“evolution directed by man.” Thus, the job of a plant breeder is to replace natural selection
with artificial selection, such that combinations of traits can be assembled into plant var-
ieties that would not otherwise be found in nature. While correct, this definition hides
many of the dimensions in which a breeder must work to produce successful plant varieties.
There are two primary interventions that a breeder makes: the deliberate hybridization of
(^1) FromMemoir, Correspondence, and Miscellanies, from the papers of Thomas Jefferson, edited by Thomas
Jefferson Randolf, 1829, p. 144.
(^2) Vavilov and Lysenko: In the plant sciences, Russia has produced one of the most influential plant scientists as well
as one of the most notorious. Nikolai Ivanovich Vavilov (1887–1943) is credited with several important discov-
eries in genetics, including the demonstration that the center of diversity of a plant species is an indication of its
center of origin. He also assembled one of the largest and most diverse collections of plant germplasm in the world,
now housed at the Vavilov Institute of Plant Industry in St. Petersburg. Trofim Denisovich Lysenko (1898–1976)
was an experimentalist who claimed the discovery of many agricultural methods that now seem absurd. To his
credit, he also studied some phenomena such as vernalization that we now recognize as important physiological
mechanisms. Unfortunately, his claims of rapid and phenomenal success were popularized to the extent that he
garnered great political influence in Stalin’s Soviet Union. When he was put in charge of the Academy of
Agricultural Sciences of the Soviet Union, he was able to silence or imprison his critics, including Vavilov,
who died in prison in 1943.
48 PLANT BREEDING