PLANT BREEDING Introduction

Introduction Improvements in agricultural crop production have occurred since mankind began cultivating crops for food.

Plant Breeding Facts The evolution of intentional plant breeding is one of the primary reasons for the dramatic improvements that have occurred with modern crop species. Data from FAO; Chart from Brian courtesy of Wikipedia.

Green Revolution During the Green Revolution, which occurred during the 1940’s to 1960’s, high-yielding varieties of maize, wheat, and rice were developed. Along with improved production technologies, these new crop varieties help save billons of people from starvation in underdevelopment countries. Dr. Norman Borlaug, shown receiving the Presidential medal of Freedom, is often called the, “Father of the Green Revolution”, for his work with crops in Mexico, India, and Pakistan. Photo by Chris Greenberg, Executive Office of the President of the United States, courtesy of Wikipedia.

What is plant breeding? Plant breeding involves the selection of certain plant characteristics based on the variability of genes within a certain plant. Successful breeding, therefore, relies on genotypic variations among individual plants within a plant species.

Why do you we practice plant breeding? Scientists use plant breeding and experimentation to increase crop yields, isolate desirable plant characteristics, and influence changes within a plant species. Photo by Scott Bauer courtesy of USDA Agricultural Research Service.

Plant Breeding Two factors that affect the success of plant breeding are: Environmental Conditions Presence of Variability in genetic material Photo by Keith Weller courtesy of USDA Agricultural Research Service.

Factors That Influence The Selection Of Crop Cultivars A goal of plant breeding is to produce new crop cultivars with improved agronomic traits. Photo by Keith Weller courtesy of USDA Agricultural Research Service.

AGRONOMY What is it? The science of soil management and crop production

Crop Cultivar A crop cultivar is a subdivision of a plant species that exhibits differences in certain agronomic traits or characteristics. Photo by Scott Bauer courtesy of USDA Agricultural Research Service.

Selecting Cultivar Process In selecting a cultivar of crop species to cultivate, a producer considers how well adapted the cultivar is to the given environment and field conditions. The producer also considers marketing and consumer preferences, and the cultivar’s resistance to pests and diseases.

Types of Plant Breeding Plant breeders work with three identifiable types of genetically controlled traits: Qualitative traits Quantitative traits Quality Enhancement traits

Qualitative Traits Qualitative traits in a plant breeding program are influenced by a small number of genes. They are not greatly influenced by the environment and they are relatively easy to manipulate.

Examples of Qualitative Traits Corn endosperm color and sorghum height are two examples of qualitative traits Photo by M. Jasek.

Quantitative Traits Quantitative traits in a plant breeding program are more difficult to control. They are influenced by environment and they involve a larger number of genes and gene pairs.

Examples of Quantative Traits One of the plant growers’ most important areas of crop improvement is yield and is typical of this grouping. Photo by Garry McMichael courtesy of USDA Photography Center.

Quality Enhancement Quality enhancement traits in a plant breeding program are relatively new concepts. These traits are selected based upon value, importance to the industry, and the ease of use with modern farming technology.

Quality Enhancement Cont’d Crops with quality enhancement traits, modified through breeding and biotechnology, may have: Higher oil and/or nutrient content Resistance to machine harvesting damage Long shelf-life after harvesting Resistance to Pest Ease of industrial processing

Quality Enhancement Example Comparison of a high salinity tolerant wheat hybrid (left) to a moderate salinity tolerant wheat cultivar. Photo by Richard Wang courtesy of USDA Agricultural Research Service.

Quality Enhancement Example Longer shelf life is an example of a quality enhancement and this illustration shows how shelf life is increased genetically by blocking the genes that cause tomatoes to soften.

Quality Enhancement Cont’d Food crop cultivars with quality enhancement traits are desirable for production because they: Are more nutritious Are easier to harvest Require less fertilizer and/or pesticide during production Produce valuable products such as oils and proteins Colorful carrot pigments provide beta carotenes and antioxidants that promote good health. Photo by Stephen Ausmus courtesy of USDA Agricultural Research Service.