History of Fruit Research
When fruit breeding began at the Arboretum's Horticultural Research Center (HRC) at the turn of the 20th century, most Minnesotans lived on farms with their own orchards to provide fruit to eat fresh in season and to preserve for the long winter. Small commercial orchards and vineyards were common. That fruit made its way, by wagon or train, to markets in nearby towns and cities with nothing left to ship to distant markets. Many fruit varieties that European settlers brought with them to Minnesota proved unsuitable for the harsh climate of the Upper Midwest so they could not be used for development.
Breeding before 1900
The initiation of fruit breeding at the University of Minnesota was due mainly to the success of the colorful and controversial Peter M. Gideon who developed the first great apple variety from the northern plains. Gideon had arrived in Minnesota in 1853 with many fruit trees to test and a bushel of apple seeds to plant. By 1868, he had identified an outstanding seedling, named Wealthy after his wife, which became one of the most important cultivars in the United States by the late 1800s and early 1900s. His success in developing and commercializing Wealthy was a primary motivator for the state legislature to fund a breeding program.
Fruit breeding at the University of Minnesota has been ongoing since 1878 when the legislature of the 20-year-young state appropriated $2000 to purchase a tract of land for an experiment station and $1000 per year for operations. Gideon was named the first superintendent of the new station, located near his farm on Lake Minnetonka in Excelsior, Minnesota. Though Peter Gideon and University administrators had their differences, he directed the program until 1889. When he retired that year at age 70, the station was abandoned.
Breeding in the Early 1900s
In 1907, the legislature appropriated funds to acquire land to establish a new Fruit Breeding Farm between Excelsior and Chaska, about 33 miles southwest of Minneapolis-St. Paul, adjacent to land that would be purchased and incorporated into the Minnesota Landscape Arboretum later in the 20th century. This Fruit Breeding Farm, now known as the Horticultural Research Center, became the center of fruit breeding for the next century. The farm was continually staffed with a superintendent and knowledgeable horticultural technicians who took active roles in fruit breeding. Through the early 20th century several faculty taught on the St. Paul campus and then in the summer traveled to the Fruit Breeding Farm by streetcar to conduct fruit breeding research. Usually they would stay in one of several cabins at the farm during the summer months, even bringing their families, thus using it as their summer research retreat.
Through the 20th century, numerous people were involved in fruit breeding. Charles Haralson, who was appointed as the first superintendent, was later honored with the naming of the Haralson apple which became the most important cultivar for several decades. Other notable assistant superintendents and technicians who were actively involved in the fruit breeding efforts included Frederick Haralson, Patrick Pierquet and Elmer Swenson. Although he spent a short time at the University of Minnesota, Swenson was especially known for his independent grape breeding efforts and is considered the godfather of cold hardy grape breeding.
Breeding from 1920s to 1970s
Several University of Minnesota faculty provided leadership to the fruit breeding programs. Over 100 fruit cultivars have been introduced during their tenure, beginning in the 1920s. During the early decades, introductions focused on apples, plums and related Prunus, as well as small fruits. Several introductions became regionally, nationally or even internationally popular. The Latham raspberry, for example, propelled Minnesota to be the third ranked state in the U.S. in raspberry acreage by the 1940s with a crop value of over a million dollars annually. Latham became widely grown in eastern North America and colder parts of Europe.
Trumpeter strawberry and Haralson and Beacon apples became regional favorites. The North Star and Meteor tart cherries and the Red Lake currant were widely grown in North America and Europe. Sungold and Moongold apricots, Parker pear, and a host of plums remain regionally popular to this day in home landscapes and gardens.
Cecil Stushnoff led the program from 1967-1980. Though he maintained a large emphasis on apple breeding, his experience as a graduate student in New Jersey also inspired an attempt to develop large-fruited, productive blueberries for cold climates. This led to a string of winter hardy half-high to ¾-high cultivars that allowed commercial, direct-market blueberry production in USDA hardiness Zones 3 and 4. Northblue and, more recently, Chippewa and Polaris have become popular commercial cultivars.
Into the 21st Century
In the late 20th and early 21st centuries, the breeding program has focused on apple, grape, blueberry and strawberry breeding. James Luby has overseen the fruit breeding program since 1982 along with David Bedford in apple breeding, David Wildung in berry breeding, and Peter Hemstad, who invigorated the grape breeding effort in 1985. In 2015, the fruit breeding effort expanded to include Matthew Clark, the new leader of the grape breeding and enology project. This period has been marked by the introduction of Honeycrisp, the first apple introduction from the program to gain world-wide interest, the MesabiTM strawberry, and Frontenac, Marquette, and La Crescent, the first high quality wine grapes from the program.
Today our fruit breeding programs develop new varieties for northern gardeners as well as commercial fruit growers. Our objective is to combine winter hardiness for northern zones with high fruit quality. In apples this means great crunch and juiciness along with sweetness and snap. Our most recent introductions include SweeTango® (Minneiska cultivar), Frostbite, Zestar!® (Minnewashta cultivar) and SnowSweet® (Wildung cultivar). Our blueberry breeding program combines the best of the cultivated highbush blueberry with the wild lowbush blueberry to bring a series of varieties from the lowbush-like Northcountry and Northsky to the taller favorites such as Chippewa, Northblue, Polaris, St. Cloud, and Superior. Our most recent blueberry introduction is PinkPopcorn®(MNPink1 cultivar) featuring blushed pink berries with classic blueberry flavor. Our wine grape breeding program and enology research program has now developed several varieties that have energized a local commercial wine industry in the upper Midwest. Marquette is known for its high quality red wines, while white varieties Frontenac gris and Frontenac blanc have set the standard for cold climate white wine grapes.
The basic process of developing new varieties is the same for all fruit crops. The first step is to choose parents, usually with complementary strengths and weaknesses. For example, a very cold hardy grape with small clusters might be crossed with a large clustered variety lacking hardiness in an attempt to combine both major qualities in the offspring.
The hybridization, or crossing, mimics cross pollination that occurs in nature - except that the breeders specifically control the parents being crossed. Just before bloom, the plant being used as the female parent is subjected to emasculation - the removal of the male organs (stamens) from the developing flower and then the covering of the flowers with a special paper bag. This process ensures that no accidental self pollination occurs and the bag keeps out unwanted insect and wind-borne pollen. Pollen is gathered from the flowers of the male parent and the plant breeder carefully pollinates the flowers of the female parent. Seeds develop over the course of the growing season and are harvested from the ripe fruit. From 200 to 500 seeds are produced from each combination of parents.
Seeds are germinated in the winter in a greenhouse and grown to a size that can be transplanted to the field. Perennial plants must pass through a juvenile phase when they are incapable of flowering. This may be just a few months in a raspberry or blueberry to several years in a grape or apple. During this juvenile phase the breeder may cull some seedlings that are susceptible to diseases, winter injury, or exhibit other problems. Finally, when the seedlings begin fruiting, the fruit can be evaluated for quality traits such as color, flavor, and texture. Most seedlings have at least one serious fault. Only the very best of the seedlings are selected for further testing - usually only about 1 or 2 percent. Each selection is given its own selection number, such as MN 1711, and this designation will identify it until it is ultimately named and introduced as a new variety - or discarded due to a serious fault that is observed.
Each selection goes into advanced testing. This involves making many copies of a selection by a cloning process such as grafting onto rootstock or rooting of cuttings. These cloned plants are then grown again to fruiting, usually at multiple locations, so that the traits of a selection become more apparent on multiple plants. The multiple plants also provide more fruit for testing of a selection. For example, wine can be made in the case of wine grapes or apples can be given to a taste panel to get their assessments of quality.
Most selections are eventually discarded but one that does show promise will be commercialized. When we have new varieties to introduce, in vitro or "test tube" micro-propagation (also called tissue culture) provides a rapid means of propagating a disease-free stock of blueberries, raspberries, and grapes in the large numbers needed to get them to commercial fruit growers and local retail nurseries. Antibody-based and molecular-genetic tools are used to detect unseen viruses and other disease organisms to ensure that stock purchased is free from these pathogens. The University of Minnesota will usually obtain a plant patent on the variety and license commercial nurseries to propagate it. The nurseries charge the consumer or fruit grower a royalty fee that is returned to the University to help support future breeding efforts.
In addition to developing new fruit varieties, one of our important research activities is learning more about the genetics of fruit crops. For example, studies are underway to determine how the great crispness and juiciness of Honeycrisp is inherited in its offspring and whether we can use DNA markers to help select the crispest offspring even before they fruit. We are also trying to find out how the wild grape parents used in our breeding have contributed disease resistance and a response to the shortened days of late summer that allows their offspring to develop cold hardiness earlier than varieties brought here from Europe. In strawberries and blueberries we have been studying the wild species related to the crop species to assess their genetic diversity for horticultural traits.
Meet the Research Scientists
James Luby, Professor
B.S. Crop Science, Purdue University
Ph.D. Plant Breeding and Genetics, University of Minnesota
Directs University of Minnesota fruit breeding programs at the Arboretum's Horticultural Research Center. Involved in introduction of over 25 fruit cultivars. Teaches courses in fruit production, viticulture and plant breeding.
Emily Hoover, Professor, Department Head
B.S. Horticulture, Michigan State University
M.S. Horticulture, University of Minnesota
Ph. D. Horticulture, University of Minnesota
Directs research in fruit crop production including rootstocks, weed and pest management. Teaches courses in fruit production, plant propagation, and plant physiology.
Matthew Clark, Assistant Professor
B.A. Psychology, Saint John's University, Collegeville, MN
M.S. Applied Plant Science: Plant Breeding and Genetics, University of Minnesota
Ph.D. Applied Plant Science: Plant Breeding and Genetics, University of Minnesota
Project leader for grape breeding and enology research. Primary research interests include developing cold-hardy, high quality wine grape varieties with improved disease resistance. Directs research for developing methodologies for best practices of cold-hardy wine grape production. Teaches courses related to winemaking, viticulture, and plant propagation.
David Bedford, Research Pomologist
B.S. Biology, Wheaton College
M.S. Horticulture, Colorado State University
Manages apple and tree fruit breeding and evaluation programs at the Arboretum's Horticultural Research Center. Involved in introduction of Honeycrisp and other recent apple varieties.