ISSUE: New sweet cherry varieties with improved fruit quality will lead to increased consumer enjoyment and consumption and will contribute to the profitability and sustainability of the U.S. sweet cherry industry. However, breeding new sweet cherry varieties is slow and inefficient and can take 15 to 25 years from the initial cross to variety release. Predicting which selections will be the best parents is difficult. Thousands of seedlings must be grown and evaluated in the orchard to identify the few that have commercial potential.

WHAT HAS BEEN DONE: Genetic tests were developed to predict cherry fruit color, fruit size, fruit firmness, and self-fruitfulness. These genetic tests enable sweet cherry breeders to determine the best parents to combine and the best seedlings to advance, reducing the need to grow out and sort through thousands of seedlings with unacceptable fruit quality.

Using this strategy, called Marker-Assisted Breeding (MAB), cherry breeders can more efficiently, accurately, and creatively develop superior cherry varieties that meet the needs and desires of consumers and producers.

IMPACT: As a result of genetic testing of 7000 seedlings, selections, and varieties in the Washington State University sweet cherry breeding program:

• Forty-two selections were chosen as parents based on their genetic potential to transmit self-fruitfulness and firm and large fruit.
• 146 crosses were designed based on their efficient paired ability to generate selffruitfulness, large fruit, and good firmness in the next generation.
• Sixteen advanced selections were characterized for their genetic potential for key traits to increase confidence in their adoption as potential new varieties
• 3735 seedlings were discarded prior to field planting based on the prediction that the flowers will be self-sterile and the fruit will be small and soft.

The collective impact of MAB is increased efficiency of identifying sweet cherries that are large, firm, and self-fruitful with potential to extend the marketing window and increase profitability. Without MAB, approximately 3.5 acres of sweet cherry seedlings with little commercial potential would have been planted and evaluated. Therefore, a projected cost of $75,000 to the Washington State University program was avoided.

 

ISSUE: New disease resistant tart cherry varieties with improved fruit quality will lead to increased consumer enjoyment and consumption and will contribute to the profitability and sustainability of the U.S. tart cherry industry. However, breeding a new tart cherry variety is slow and inefficient. Predicting which selections will be the best parents is difficult. Hundreds of progeny individuals must be grown and tested in the orchard to identify the few with commercial potential.

WHAT HAS BEEN DONE: DNA tests were developed to predict cherry fruit and pit size, cherry skin and flesh color, self-fruitfulness, and resistance to cherry leaf spot fungus. These genetic tests enable tart cherry breeders to determine the best parents to combine and the best seedlings to advance, reducing the need to grow out and sort through hundreds of seedlings with unacceptable fruit quality or disease susceptibility.

Using this strategy, called Marker-Assisted Breeding (MAB), cherry breeders can more efficiently, accurately, and creatively develop superior tart cherry varieties that meet the needs and desires of consumers and producers.

IMPACT: As a result of genetic testing in the Michigan State University tart cherry breeding program:

• About 30 percent of seedlings from one cross were discarded prior to orchard planting because DNA tests identified them as derived from unintended parentage.
• Twenty-five crosses were designed based on their increased potential for transmitting the desired red skin and light red juice color to their offspring.
• Seedlings predicted to be resistant to cherry leaf spot were propagated on a rootstock that induces early flowering. This new activity will reduce by two years the time required to breed disease resistant varieties.
• In 2014, seedlings from 10 crosses will be DNA tested to discard those seedlings that are predicted to have undesirable fruit color, thus avoiding future expenses for growing and evaluating these seedlings.

The collective impact of MAB is increased efficiency of identifying new tart cherry varieties. Resources needed to grow seedlings to maturity can be targeted to those individuals with a greater chance of having the desired trait attributes.