Breeding of Ornamental Pears

* First breeding project started in 1991

* Utilized pear species collection at the USDA Clonal Plant Germplasm Repository in Corvallis, Oregon
* Crosses were made between 10 different Pyrus species in almost all possible combinations
* Crosses were also made with existing F1 hybrids
* F1 hybrid populations grown at WSU - Puyallup Research and the Oregon Extension Station

Carpinus Breeding

* Cooperative project between LPDC and The Morton Arboretum
* Used plant collections of Morris Arboretum, U.S. National Arboretum, Arnold Arboretum, Holden Arboretum and the Morton Arboretum to make original crosses

* These hybrids are now growing at the Oregon Research Station

Carpinus Progress Report

* Many of the F1 hybrids have very nice plant form and excellent foliage qualities.
* Beginning to make selections for propagation and further evaluation.
* Many of the F1 hybrids are now flowering
* Seed is being collected for the growing out of the F2 generation

Maple Breeding

* Cooperative project between LPDC and The Morton Arboretum
* Used plant collections of Morris Arboretum, U.S. National Arboretum, Arnold Arboretum, Holden Arboretum and the Morton Arboretum to make original crosses
* Cold hardiness potential
* These hybrids are now growing at the Oregon Research Station and the Morton Arboretum

Maple Progress

* F2 generation seedling from controlled crosses made in 2004 are now being grown at the Morton Arboretum, these trees are developing nicely.
* Open pollinated seed collected in 2005 is now growing at Bailey Nurseries, Inc. in Minnesota. Seedling will be left in seedbeds through the winter of 2007 to select for cold hardiness.
* Began planting approximately 75 seedlings at the Minnesota Research Station for cold hardiness testing.

Mountain Ash Breeding - Intergeneric Hybrids

* Cooperative effort with University of Minnesota
* Long term project of Harold Pellett

Clematis Breeding

* Developing non-vining cultivars hybrids between Clematis integrifolia and C. hexapetala

* Hybridizing between C. integrifolia rosea with C. hexapetala and large flowered vining cultivars in an attempt to extend flower color range

Clematis Progress

* The Center has made excellent progress
* Many plants are now growing in Minnesota and some in Oregon
* Donahue’s Greenhouse has been licensed to grow ‘Center Star’ and is currently propagating to build up numbers.

Breeding for Improved Native Woody Plants

* In 2003-2004, the Center collected native woody plants in Iowa, Michigan and Minnesota
* Cooperative effort between Dr. Robert Schutzki of Michigan State University, Dr. Mark Widrlechner of North Central Regional Plant Introduction Station in Iowa and Dr. Harold Pellett, LPDC
* These are being grown out to select superior individual plants and will be utilized in our breeding efforts
* The Center is using Ethyl Methane Sulfonate to develop dwarf varieties of selected plants.
* Three plants of Cephalanthus occidentalis were selected from seedlings treated with EMS and are growing at our Oregon station.

Developing Sterile Cultivars

* Eliminate fruit litter, invasiveness, unsightly seedheads and improve flowering
* Cooperative work with Dr. Tom Ranney at NCSU, Mtn. Horticulture Research Center
* Achieved by ploidy manipulation or genetic transformation
- treat tissue with a spindle fiber inhibitor to double the chromosome number
- determine ploidy level by flow cytometry
- cross induced tetraploids with normal diploid plants and grow out offspring to verify presence of triploids
- grow triploids to maturity to observe fertility, hopefully sterile

Sterile Plant Progress

* Tetraploids of crabapple, Acer platanoides and Acer ginnala have been verified
* Have noted several pear selections that appear sterile
* Some of our Buddleia seedlings appear to be sterile or of low fertility, we anticipate several sterile selections with excellent ornamental traits.
* Dr. Ranney has used pollen from some of our slected pear hybrids to make crosses with tetraploid Pyrus calleryana that he has induced.
* In our cooperative breeding program with North Dakota State University, Dr. David Dai has successfully established plants of several species in tissue culture
* Dr. Dai has developed a satisfactory protocol for gene transformation with Buddleia
* Our hope is to introduce genes that result in sterility and dwarfness.

Potential Gains by Genetic Engineering

* Development of sterile cultivars
* Modification of plant form and size
* Modification of flower color
* Insect and disease resistance

Weigela Breeding

* Cold hardiness
* Shorter more compact plants with novel blossom color and extended bloom cycle.
* Plants with better foliage colors that include dark red, bronze and gold.

Diervilla Breeding

* An extremely adaptable and resilient native plant that until now has not had much diversity in terms of flower color, flower size, habit and leaf color.
* We have produced exciting plants with bold variegated foliage, bronze leaf color and pink flowers.

Buddleia Breeding

* General goals are to tame this garden favorite. Efforts have produced sterile plants with much more compact habit. Color range has been expanded and flower size has been increased. We hope to permanently sterilize any selections we release through molecular techniques as well.
* Breeding has been done all year long in the greenhouse allowing us to produce three generations per year. Currently we have accomplished what would have normally taken twelve years outdoors in just four years.

Oak Breeding Objectives

* Great progress in combining the best qualities of hardy species that are tolerant of compacted soils with species from Mexico and the Desert Southwest that tolerate high pH and salt.
* Improve the rooting potential of valuable urban forestry species by crossing them with easy-to-root species