Plant breeding involves selecting plants for reproduction in the hopes of producing offspring that have preferred traits. Plant breeding, in its most basic form, goes back thousands of years in human history. Ancient farmers selected the seeds of the most desirable plants and saved them to grow the next season. Understanding the principles behind modern, scientific plant breeding is the key to successfully creating new desirable varieties. Does this Spark an idea?
Genes
The science of genetics forms the foundation of plant breeding. Genes, a basic component of every living cell, determine the characteristics, such as size or color, which the parent plant passes on to its progeny. Most cells contain two genes for each trait. Each parent plant contributes a gene for each inheritable trait to the offspring. For example, each parent may contribute a gene for the color red. In that case, with two red genes, the plant will have a red flower. If one parent contributes a red gene and the other a yellow gene, then the flowers will have a red color or a hue in between red and yellow, depending on how strongly the red gene dominates the yellow gene.
Quantitative Traits
Not every trait is governed by one or even a few genes. Some complex traits, such as drought resistance, have numerous genes that contribute to the desired characteristic. These types of attributes, called quantitative traits by scientists, may be quite difficult to produce since they involve the interplay of so many genes. Other quantitative traits include fruit size and yield. When attempting to select for quantitative traits, plant breeders might need to propagate many generations of plants before obtaining the desired characteristic.
Pollination
Plant breeding centers around pollination, the process by which a seed is formed. The male part of a flower, the anther, produces a substance called pollen that fertilizes the stigma, the female part of a flower. Self-pollination occurs when pollen from an anther fertilizes the female part of the same flower or a different flower that grows on the same plant, according to the University of Illinois. In cross-pollination, pollen fertilizes a flower on a different plant. In plant breeding, the pollen parent contributes the pollen, while the seed parent receives the pollen.
Reasons
Growers have various reasons for breeding plants. Farmers might want a more durable type of grain. For instance, farmers bred a specific type of sorghum to make it viable outside of its native habitat in the southwestern U.S. Growers who wish to create more desirable ornamentals might want a longer time for a flower to remain in bloom or a larger or smaller plant size. For a citrus grower, fruit size might have a critical importance.
Tags: quantitative traits, contributes gene, desired characteristic, female part, flower different, fruit size, might want
