Source: MICHIGAN STATE UNIV submitted to
GENETIC IMPROVEMENT OF SOUR CHERRY AND CHERRY ROOTSTOCKS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
NEW
Funding Source
Reporting Frequency
Annual
Accession No.
1003036
Grant No.
(N/A)
Project No.
MICL02332
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Jul 1, 2014
Project End Date
Jun 30, 2019
Grant Year
(N/A)
Project Director
Iezzoni, AM, .
Recipient Organization
MICHIGAN STATE UNIV
(N/A)
EAST LANSING,MI 48824
Performing Department
Horticulture
Non Technical Summary
The sour and sweet cherry industries are important contributors to Michigan's fruit production. To remain profitable in a global economy, the Michigan cherry industries must produce excellent quality fruit and mitigate risks due to disease and climatic stresses. The Michigan sour cherry industry, which represents approximately 60 percent of the U.S. production, is essentially a monoculture of the 400 year-old cultivar, 'Montmorency'. Unfortunately this 'Montmorency' monoculture provides an ideal environment for extensive crop losses due to unfavorable weather conditions and disease threats. Floral spring freeze damage resulted in near complete crop losses in 2002 and 2012. Cherry leaf spot is the most important disease threat where failure to control the causal fungus results in early defoliation leading to poor fruit quality and loss of winter hardiness. Chemical controls are costly, management can be challenging depending upon weather conditions, and potential regulatory changes threaten use of certain classes of controlling chemicals. Fortunately sour cherry selections exist that are being used as parents to donate late bloom time and cherry leaf spot resistance with the goal of combining these risk-mitigating traits with productivity and superior fruit quality. A second disease threat to the Michigan sweet and sour cherry industries is the soil-borne root rot fungus, Armillaria. Orchards infected with Armillaria have a gradual tree loss until the orchard is prematurely abandoned and removed. Because Armillaria is persistent in the soil and there are no cultural practices to manage the disease, infected orchard sites can no longer be used for cherry production, and frequently the land is sold for development. The wild species Prunus maackii, which is tolerant to Armillaria, is being used to breed rootstocks tolerant to this fungus. Rootstocks can also confer beneficial horticultural traits to the scion such as precocious flowering and reduced tree size. Precocious, dwarfing rootstocks allow cherry growers to adopt high efficiency orchard systems and enhance profitability through earlier and increased yields, higher quality fruit, and reduced unit costs of production. All sour cherry and many sweet cherry trees in Michigan are on standard size rootstocks, with trees only coming into commercial production by approximately year six. Recently there is interest in using dwarfing precocious rootstocks to enable 'Montmorency' trees to be planted at high densities and harvested in year three with an over-the-row harvester. Currently five Michigan State University cherry rootstocks are being tested that induce scion dwarfing and precocity and therefore have the potential to enable high density sour and sweet cherry orchards with increased early fruit production. Both the scion and rootstock breeding programs will be more efficient and effective using knowledge of the genetic control of important breeding trait targets. The availability of genetic maps and whole genome sequences has led to a rapid increase in the pace of genetic discovery. As genetic discoveries become available they will be translated into breeding application. Examples of these marker-assisted breeding applications include using DNA knowledge to choose breeding parents, design crosses, and pre-select seedlings for field planting thereby culling those predicted to be undesirable.
Animal Health Component
0%
Research Effort Categories
Basic
20%
Applied
80%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
20111121081100%
Knowledge Area
201 - Plant Genome, Genetics, and Genetic Mechanisms;

Subject Of Investigation
1112 - Cherry;

Field Of Science
1081 - Breeding;
Goals / Objectives
The overall goal is to develop new commercial sour cherry cultivars and rootstocks that increase industry profitability and sustainability. Specific goals are to: (1) Develop sour cherry cultivars for Michigan and areas of similar climate while maintaining acceptable yields through improving fruit quality, cherry leaf spot resistance and spring frost avoidance. (2) Develop new cherry rootstocks that are tolerant to Armillaria and/or promote precocious scion flowering and dwarfing. (3) Discover and utilize new genetic knowledge to enhance the effectiveness of the MSU breeding programs.
Project Methods
SOUR CHERRY BREEDING: Hybridizations will be made in the spring to continue to combine superior fruit quality and productivity with disease resistance. As DNA information becomes available for fruit and disease resistance traits, it will be used to choose parents for hybridizations and to eliminate undesirable seedlings prior to field planting. The remaining seedlings will be planted at the Michigan State University Clarksville Research Center and evaluated for the following key traits: bloom time, productivity, fruit quality, and disease resistance. Superior selections will be propagated for further testing at Michigan State University research stations and grower-cooperator orchards. ARMILLARIA CHERRY ROOTSTOCK BREEDING: The rootstock seedlings resulting from crosses with P. maackii made will be clonally increased and then screened for Armillaria tolerance using a wood extraction assay. Any seedling(s) exhibiting Armillaria tolerance will be budded with sour cherry scion to determine graft compatibility. These grafted trees will be planted in an Armillaria-infected site to assess field tolerance. DWARFING PRECOCIOUS CHERRY ROOTSTOCKS: The performance of the MSU candidate cherry rootstocks in an over-the-row production system will be evaluated in existing trials at MSU's Northwest Horticultural Research Center and grower trials planted in Michigan. The suitability of the MSU candidate cherry rootstocks to enable a pedestrian sweet cherry orchard system will be evaluated with trials to be planted in other cherry production regions, including Washington and Oregon. Yield/trunk cross-sectional area and fruit quality traits will be recorded from trees in these trials. CHERRY GENETICS: Progeny populations segregating for bloom time, critical fruit quality traits (fruit firmness, shape and size; pit freestone/clingstone and shape), and cherry leaf spot resistance are available at the Michigan State University Clarksville Research Center. Phenotypic data for these traits will be collected for two years/trait. Major loci/QTL controlling phenotypic variation for these traits will be identified from previous work in sweet cherry and other Prunus crops. Using the available peach genomic sequence, simple sequence repeat markers will be designed that distinguish alleles for these target genomic regions in sour cherry. These markers will be tested to determine if candidate loci from other Prunus species control variation for the target trait in sour cherry. If so, these markers become potential DNA tests for utilization in the breeding program.

Progress 10/01/16 to 09/30/17

Outputs
Target Audience:Target audiences include Prunus breeders and allied scientists, cherry growers, processors and marketing organizations, the tree fruit nursery industry, and consumers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?A technician, one graduate student and two undergraduate students contributed to this work. How have the results been disseminated to communities of interest?Communities of interest received project results via presentations at industry meetings and field days, discussions of the project leader with the breeding program's industry advisory committee, and journal publications. What do you plan to do during the next reporting period to accomplish the goals?Sour cherry breeding: Hybridizations will be made in the spring between individuals projected to be superior parents. The resulting seedlings will be grown in a greenhouse at the MSU campus. Seedlings from families predicted to be segregating for self-in/compatibility, dark flesh color, and P. canescens-derived cherry leaf spot resistance will be screened using DNA markers to identify undesirable individuals. Those individuals predicted to have the undesirable traits will be discarded prior to field planting at MSU's Clarksville Research Center. Seedlings predicted to be especially useful due to their combination of alleles will be budded on precocious rootstocks to accelerate flowering and fruiting. Seedlings planted in the field in prior years will be evaluated for numerous horticultural traits including bloom date, harvest date, fruiting habit, and fresh and frozen fruit quality characteristics. A major new focus in 2017 will be early ripening selections, especially individuals that bloom late and ripen early. Due to pressure from the new invasive insect, Spotted Winged Drosophila, harvesting sour cherry at an earlier time in the season has the potential to increase grower profitability due to fewer sprays required to control this insect threat. Superior selections will be propagated and planted at five test sites in Michigan to provide additional locations to observe these selections plus sufficient trees for yield data, mechanical harvesting and fruit for pilot processing trials. Cherry rootstock breeding: Armillaria resistance: Roots from rootstock seedlings resulting from crosses with P. maackii will be screened using a fungal bioassay to assess their fungal resistance. Any individual that exhibits fungicidal activity will be propagated to provide clonal replicates for field screening for Armillaria resistance and for budding with 'Montmorency' scion to evaluate graft incompatibility. Growth, tree health, tree survival and horticultural performance will continue to be monitored for the 'Montmorency' P. maackii and P. mahaleb trees planted at the Armillaria site and for the P. maackii trees with 'Montmorency' scion. Any dead trees will be evaluated to determine the cause of death. Dwarfing precocious rootstocks: The suitability of the MSU candidate cherry rootstocks to enable an over-the-row production system for sour cherry and a pedestrial orchard for sweet cherry will be evaluated in existing trials in Michigan, Washington, and Oregon. Yield/trunk cross-sectional area will be recorded from trees in these trials along with fruit quality parameters (size, firmness, and soluble solids). Cherry genetics: Progeny populations segregating for cherry leaf spot resistance and tolerance from multiple donors, bloom time, fruit firmness, and yield will be genotyped using the Illumina SNP chip to provide marker data for genetic analyses. The genetic data will be used to attempt to identify genomic regions significantly associated with variation for these traits. If successful, these loci will be targeted for further analyses with the ultimate goal of implementing marker-assisted selection to increase breeding efficiency.

Impacts
What was accomplished under these goals? Sour cherry breeding: Sour cherry seedlings planted in the field were evaluated for numerous horticultural traits including bloom time, harvest date, fruiting habit, fresh and frozen fruit quality characteristics, and cherry leaf spot resistance and tolerance from multiple donors. Very late blooming progeny were prevalent in the newly blooming seedlings indicating that it is possible to significantly delay cherry bloom to reduce the likelihood of spring freeze damage to flowers. Superior selections were identified to use as parents in crosses to continue to combine disease resistance/tolerance and late bloom time with excellent fruit quality and high yield. Additionally crosses with sweet cherry were made to introgress the tolerance to cherry leaf spot present in this species into sour cherry. Breeding efficiency was increased by the use of DNA tests for fruit flesh color and Prunus canescens-derived cherry leaf spot resistance. Seedlings from crosses that were predicted to segregate for these traits were screened using DNA tests and only those seedlings with the desirable fruit color and disease resistance alleles were planted in the breeding orchard. Rootstock breeding: Armillaria resistance: Six Michigan field trials planted in 2016 to determine if the putatively Armillaria resistant species P. maackii has commercial potential as a rootstock for cherry production were monitored. These plots compare the sour cherry scion cultivar 'Montmorency' grafted on P. maackii or the standard rootstock P. mahaleb. Four of the plots are on infested sites to evaluation the Armillaria - P. maackii disease reaction. The other two plots are designed to determine if the 'Montmorency'/P. maackii combination is graft compatible and will result in high yielding trees with acceptable tree and fruit qualities. To date, none of the trees in the plots (on either P. maackii or P. mahaleb rootstocks) have died from Armillaria, however, tree death typically begins in year 4 or 5. Hybrid rootstocks made in the breeding program with P. maackii were propagated and will be advanced to orchard tests pending the confirmation of field resistance. Dwarfing precocious rootstocks: Five MSU cherry rootstocks that increase scion precocity and dwarfing have entered the second testing phase, including the filing of patent applications. For sweet cherry, three trials comparing the MSU cherry rootstocks with other size controlling rootstocks were planted in grower orchards in spring 2015 in Oregon (one site) and Washington (two sites). The trees were planted and trained according to high density orchard systems to determine the rootstocks and training systems most likely to result in profitable production. Yield data from 2017 indicated that these rootstocks grown in high density production systems would result in fruit production in year 2 compared to in production in 3 to 5 for standard orchard systems. For sour cherry, yield data was obtained from existing rootstocks trials at the Michigan State University Northwest Horticultural Research Center. The findings indicated that the MSU rootstocks are suitable for an over-the-row harvest planting system compared to the sour cherry commercial standard non-dwarfing rootstock, P. mahaleb, but productivity and tree stress tolerance varied among the five rootstocks. An additional eight trials comparing the MSU rootstocks and other size controlling rootstocks were planted in 2017 with both sweet and sour cherry scions in Washington, Oregon and Michigan, and also included in NC140 trials in Washington, Michigan, Wisconsin, New York, and Utah. Cherry genetics: Phenotypic data was recorded for sour cherry progeny populations segregating for high priority traits to include bloom date, maturity date, fruit firmness, pit freeststone/clingstone and yield. This data will be used to determine the genetic control of these traits with the goal of developing DNA tests that can be used to increase breeding efficiency. Quantitative trait loci (QTL) were identified for bloom time on cherry linkage groups 1, 2, 4 and 5.

Publications

  • Type: Books Status: Published Year Published: 2017 Citation: Quero-Garc�a J, Iezzoni A, Pulawska J and Lang G (eds). 2017. Cherries: Botany, Production and Uses. CAB International, Wallingford, UK.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Iezzoni, A.F. 2017. Advances in DNA markers in cherry: from the S-locus to a genome wide array. Acta Hortic 1161:15-20.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Sebolt, A.M., Iezzoni, A.F., and T. Tsukamoto. 2017. S-genotyping of cultivars and breeding selections of sour cherry (Prunus cerasus L.) in the Michigan State University sour cherry breeding program. Acta Hortic. 1161: 31-40.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Andersen, K.L., Sebolt, A.M., Sundin, G.W., and A.F. Iezzoni. 2017. Assessment of the inheritance of resistance and tolerance in cherry (Prunus sp.) to Blumeriella jaapii, the causal agent of cherry leaf spot. Plant Pathology doi:10.1111/ppa.12765.


Progress 10/01/15 to 09/30/16

Outputs
Target Audience:Target audiences include Prunus breeders and allied scientists, cherry growers, processors and marketing organizations, the tree fruit nursery industry, and consumers. Changes/Problems:Cherry leaf spot fungal isolates were identified that had overcome the Prunus canescens-derived resistance. As a result, in 2016 additional crosses were made to increase the program activity focused on achieving cherry leaf spot tolerance using sweet cherry as the tolerant donor. What opportunities for training and professional development has the project provided?A technician, one graduate student and one undergraduate student contributed to this work. How have the results been disseminated to communities of interest?Communities of interest received project results via presentations at industry meetings and field days, and discussions of the project leader with the breeding program's industry advisory committee. What do you plan to do during the next reporting period to accomplish the goals?Sour cherry breeding: Hybridizations will be made in the spring between individuals projected to be superior parents. The resulting seedlings will be grown in a greenhouse at the MSU campus. Seedlings from families predicted to be segregating for self-in/compatibility, dark flesh color, and P. canescens-derived cherry leaf spot resistance will be screened using DNA markers to identify undesirable individuals. Those individuals predicted to have the undesirable trait will be discarded prior to field planting at MSU's Clarksville Research Center. Seedlings predicted to be especially useful due to their combination of alleles will be budded on precocious rootstocks to accelerate flowering and fruiting. Seedlings planted in the field in prior years will be evaluated for numerous horticultural traits including: bloom date, harvest date, fruiting habit, and fresh and frozen fruit quality characteristics. Superior selections will be propagated and planted at five test sites in Michigan to provide additional locations to observe these selections plus sufficient trees for yield data, mechanical harvesting and fruit for pilot processing trials. Cherry rootstock breeding: Armillaria resistance: Rootstock seedlings resulting from crosses with P. maackii will be screened using a fungal bioassay to assess their fungal resistance. Any individual that exhibits fungicidal activity will be propagated to provide clonal replicates for field screening for Armillaria resistance and for budding with 'Montmorency' scion to evaluate graft incompatibility. Growth will continue to be monitored for the P. maackii trees planted at the Armillaria site and for the P. maackii trees with 'Montmorency' scion. Six trials that were planted in Michigan in spring 2016 to determine the Armillaria resistance and horticultural characteristics for sour cherry cv. Montmorency and sweet cherry cv. Napoleon grafted on seedling P. maackii rootstocks will be monitored for tree growth and survival. Dwarfing precocious rootstocks: The suitability of the MSU candidate cherry rootstocks to enable an over-the-row production system will be evaluated in existing trials at MSU's Northwest Horticultural Research Center. Yield/trunk cross-sectional area will be recorded from trees in these trials along with fruit quality parameters (size, firmness, and soluble solids). The suitability of the MSU candidate cherry rootstocks to enable a pedestrian sweet cherry orchard system will be evaluated with trials that were planted in Washington and Oregon in spring of 2015. Cherry genetics: Progeny populations segregating for cherry leaf spot resistance and tolerance from multiple donors, fruit firmness, and yield will be phenotyped for in 2017. These progeny will also be genotyped using the Illumina SNP chip to provide marker data for genetic analyses. The genetic data will be used to attempt to identify genomic regions significantly associated with variation for these traits. If successful, these loci will be targeted for further analyses with the ultimate goal of implementing marker-assisted selection to increase breeding efficiency.

Impacts
What was accomplished under these goals? Sour cherry breeding: Sour cherry seedlings planted in the field were evaluated for numerous horticultural traits including harvest date, fruiting habit, fresh and frozen fruit quality characteristics, and cherry leaf spot resistance and tolerance from multiple donors. Superior selections were identified to use as parents in crosses in spring of 2016 to continue to combine disease resistance/tolerance and late bloom time with excellent fruit quality and high yield. Breeding efficiency was increased by the use of DNA tests for fruit flesh color and Prunus canescens-derived cherry leaf spot resistance. Seedlings from crosses made in spring 2015 that were predicted to segregate for these traits were screened using DNA tests and only those seedlings with the desirable fruit color and disease resistance alleles were planted in the breeding orchard. Rootstock breeding: Armillaria resistance: Seedlings obtained from crosses between the putatively Armillaria resistant species P. maackii and sour cherry were planted at the Michigan State University Clarksville Research Center. These seedlings represent the first generation in the process of introgressing Armillaria resistance into a commercial cherry rootstock. In addition, experiments to provide insights into the use of P. maackii as a resistant source were advanced after two (out of 11) P. maackii seedlings planted in 2013 in a heavily infested Armillaria orchard died presumably due to a very virulent Armillaria isolate. This spring, trees of the sour cherry cultivar 'Montmorency' grafted on P. maackii were planted on four Armillaria infected sites to further investigation the Armillaria - P. maackii disease reaction. Additionally, two plots of 'Montmorency' grafted onto P. maackii seedlings were also planted to determine if this combination is graft compatible and will result in high yielding trees with acceptable tree and fruit qualities. Dwarfing precocious rootstocks: Five MSU cherry rootstocks that increase scion precocity and dwarfing have entered the second testing phase. For sweet cherry, three trials comparing the MSU cherry rootstocks with other size controlling rootstocks were planted in grower orchards in spring 2015 in Oregon (one site) and Washington (two sites). The trees were planted and trained according to high density orchard systems to determine the rootstocks and training systems most likely to result in profitable production. For sour cherry, yield data was obtained from existing rootstocks trials at the Michigan State University Northwest Horticultural Research Center. The findings indicated that the MSU rootstocks are suitable for an over-the-row harvest planting system compared to the sour cherry commercial standard non-dwarfing rootstock, P. mahalab, but productivity and tree stress tolerance varied among the five rootstocks. Cherry genetics: Phenotypic data was recorded for sour cherry progeny populations segregating for high priority traits to include cherry leaf spot resistance and tolerance from multiple donors, fruit firmness, pit freeststone/clingstone and yield. This data will be used to determine the genetic control of these traits with the goal of developing DNA tests that can be used to increase breeding efficiency.

Publications


    Progress 10/01/14 to 09/30/15

    Outputs
    Target Audience:Target audiences include Prunus breeders and allied scientists, cherry growers, processors and marketing organizations, the tree fruit nursery industry, and consumers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?A technician, one graduate student and one undergraduate student contributed to this work. How have the results been disseminated to communities of interest?Communities of interest received project results via presentations at industry meetings and field days, and discussions of the project leader with the breeding program's industry advisory committee. What do you plan to do during the next reporting period to accomplish the goals?Sour cherry breeding: Hybridizations will be made in the spring between individuals projected to be superior parents. The resulting seedlings will be grown in a greenhouse at the MSU campus. Seedlings from families predicted to be segregating for self-in/compatibility, dark flesh color, and P. canescens-derived cherry leaf spot resistance will be screened using DNA markers to identify undesirable individuals. Those individuals predicted to have the undesirable trait will be discarded prior to field planting at MSU's Clarksville Research Center. Seedlings predicted to be especially useful due to their combination of alleles will be budded on precocious rootstocks to accelerate flowering and fruiting. Seedlings planted in the field in prior years will be evaluated for numerous horticultural traits including: bloom date, harvest date, fruiting habit, and fresh and frozen fruit quality characteristics. Superior selections will be propagated and planted at five test sites in Michigan to provide additional locations to observe these selections plus sufficient trees for yield data, mechanical harvesting and fruit for pilot processing trials. Cherry rootstock breeding: Armillaria resistance: Rootstock seedlings resulting from crosses with P. maackii will be screened using a fungal bioassay to assess their fungal resistance. Any individual that exhibits fungicidal activity will be propagated to provide clonal replicates for field screening for Armillaria resistance and for budding with 'Montmorency' scion to evaluate graft incompatibility. Growth will continue to be monitored for the P. maackii trees planted at the Armillaria site and for the P. maackii trees with 'Montmorency' scion. Six trials will be planted in Michigan in spring 2016 to determine the Armillaria resistance and horticultural characteristics for the sour cherry cv. Montmorency and the sweet cherry cv. Napoleon grafted on seedling P. maackii rootstocks. Dwarfing precocious rootstocks: The suitability of the MSU candidate cherry rootstocks to enable an over-the-row production system will be evaluated in existing trials at MSU's Northwest Horticultural Research Center. Yield/trunk cross-sectional area will be recorded from trees in these trials along with fruit quality parameters (size, firmness, and soluble solids). The suitability of the MSU candidate cherry rootstocks to enable a pedestrian sweet cherry orchard system will be evaluated with trials to planted in Washington and Oregon in spring of 2015. Cherry genetics: Progeny populations segregating for cherry leaf spot resistance and tolerance from multiple donors, fruit firmness, and yield will be phenotyped for a second year in 2016. These progeny will also be genotyped using the 6K Illumina Infinium II SNP array to provide marker data for genetic analyses. The genetic data will be used to attempt to identify genomic regions significantly associated with variation for these traits. If successful, these loci will be targeted for further analyses with the ultimate goal of implementing marker-assisted selection to increase breeding efficiency.

    Impacts
    What was accomplished under these goals? Sour cherry breeding: Sour cherry seedlings planted in the field were evaluated for numerous horticultural traits including harvest date, fruiting habit, fresh and frozen fruit quality characteristics, and cherry leaf spot resistance and tolerance from multiple donors. Superior selections were identified to use as parents in crosses in spring of 2016 to continue to combine disease resistance/tolerance and late bloom time with excellent fruit quality and high yield. Breeding efficiency was increased by the use of DNA tests for fruit flesh color and Prunus canescens-derived cherry leaf spot resistance. Seedlings from crosses made in spring 2014 that were predicted to segregate for these traits were screened using DNA tests and only those seedlings with the desirable fruit color and disease resistance alleles were planted in the breeding orchard. Rootstock breeding: Armillaria resistance: Seedlings obtained from crosses between the Armillaria resistant species P. maackii and sour cherry were planted at the Michigan State University Clarksville Research Center. These seedlings represent the first generation in the process of introgressing Armillaria resistance into a commercial cherry rootstock. In addition, two experiments that were initiated with P. maackii to provide insights into the use of this resistant species as a Prunus rootstock, were advanced. P. maackii seedlings planted in 2013 in a heavily infested Armillaria orchard were observed to be growing well, supporting the prior laboratory observation of Armillaria resistance. The sour cherry cultivar 'Montmorency' was grafted onto P. maackii seedlings in 2013. These trees are growing well suggesting that sour cherry and P. maackii may be graft compatible. Therefore, trees were propagated for spring 2016 planting to determine if 'Montmorency' grafted on P. maackii will result in high yielding Armillaria resistant trees with acceptable tree and fruit qualities. Dwarfing precocious rootstocks: Five MSU cherry rootstocks that increase scion precocity and dwarfing have entered the second testing phase. For sweet cherry, three trials comparing the MSU cherry rootstocks with other size controlling rootstocks were planted in grower orchards in spring 2015 in Oregon (one site) and Washington (two sites). The trees were planted and trained according to high density orchard systems to determine the rootstocks and training systems most likely to result in profitable production. For tart cherry, yield data was obtained from existing rootstocks trials at the Michigan State University Northwest Horticultural Research Center. The findings indicated that the MSU rootstocks result in trees that are suitable for an over-the-row harvest planting system and will result in higher yields per acre when compared to tart cherry trees propagated on the commercial standard non-dwarfing rootstock, P. mahalab. Cherry genetics: Phenotypic data was recorded for sour cherry progeny populations segregating for high priority traits to include cherry leaf spot resistance and tolerance from multiple donors, fruit firmness and yield. This data will be used to determine the genetic control of these traits with the goal of developing DNA tests that can be used to increase breeding efficiency.

    Publications

    • Type: Journal Articles Status: Published Year Published: 2015 Citation: Stegmeir, T., Cai, L., Basundari, F.R.A., Sebolt, A.M and Iezzoni, A.F. 2015. A DNA test for fruit flesh color in tetraploid sour cherry (Prunus cerasus L.). Molecular Breeding 35: 149.


    Progress 07/01/14 to 09/30/14

    Outputs
    Target Audience: Target audiences include Prunus breeders and allied scientists, cherry growers, processors and marketing organizations, the tree fruit nursery industry, and consumers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? A technician, one graduate student and one undergraduate student contributed to this work. How have the results been disseminated to communities of interest? Communities of interest received project results via face-to-face industry meetings and field days. What do you plan to do during the next reporting period to accomplish the goals? Sour cherry breeding: Hybridizations will be made in the spring between individuals projected to be superior parents. The resulting seedlings will be grown in a greenhouse at the MSU Campus. Seedlings from families predicted to be segregating for self-in/compatibility, dark flesh color, and P. canescens-derived CLS resistance will be screened using DNA markers to identify undesirable individuals. Those individuals predicted to have the undesirable trait will be discarded prior to field planting at MSU’s Clarksville Research Center. Seedlings predicted to be especially useful due to their combination of alleles will be budded on precocious rootstocks to accelerate flowering and fruiting. Seedlings planted in the field in prior years will be evaluated for numerous horticultural traits including: bloom date, harvest date, fruiting habit, and fresh and frozen fruit quality characteristics. Superior selections will be propagated and planted at five test sites in Michigan to will provide additional locations to observe these selections plus sufficient trees for yield data, mechanical harvesting and fruit for pilot processing trials. Cherry rootstock breeding: Armillaria resistance: Rootstock seedlings resulting from crosses with P. maackii will be vegetatively propagated to provide clonal replicates for screening for Armillaria resistance and for budding with ‘Montmorency’ scion to evaluate graft incompatibility. Growth will continue to be be monitored for the P. maackii trees planted at the Armillaria site and for the P. maackii trees with ‘Montmorency’ scion. Dwarfing precocious rootstocks: The suitability of the MSU candidate cherry rootstocks to enable an over-the-row production system will be evaluated in existing trials at MSU’s Northwest Horticultural Research Center. Yield/trunk cross-sectional area will be recorded from trees in these trials along with fruit quality parameters (size, firmness, and soluble solids). The suitability of the MSU candidate cherry rootstocks to enable a pedestrian sweet cherry orchard system will be evaluated with trials to be planted in Washington and Oregon in spring of 2015. In both the sour and sweet cherry trials, the control rootstocks will be from the Gisela® series. Cherry genetics: Progeny populations segregating for bloom time, critical fruit quality traits (fruit firmness, shape and size; pit freestone/clingstone and shape), and cherry leaf spot resistance are available at the Clarksville Research Center. Phenotypic data for these traits will be collected. Major loci/QTL controlling phenotypic variation for these traits will be identified from previous work in sweet cherry and other Prunus crops. Using the available peach genomic sequence, simple sequence repeat markers will be designed that will distinguish allelic variants for these target genomic regions in sour cherry. These markers will be tested to determine if the candidate loci control variation for the target trait in sour cherry. If so, these markers become potential DNA tests for utilization in the breeding program.

    Impacts
    What was accomplished under these goals? Sour cherry breeding and genetics: Sour cherry seedlings planted in the field were evaluated for numerous horticultural traits including harvest date, fruiting habit, and fresh and frozen fruit quality characteristics. Superior selections were identified to use as parents in crosses in spring of 2015. A progeny population segregating for critical fruit quality traits were evaluated (fruit firmness, shape and size; pit freestone/clingstone and shape) to provide phenotypic data that will be used to search for quantitative trait loci controlling the variation for these traits. Rootstock breeding: Seedlings from crosses between the Armillaria resistant species Prunus maackii and sour cherry were obtained and represent the first generation in the process of introgressing Armillaria resistance into a commercial cherry rootstock. In addition, two experiments were initiated with Prunus maackii to provide insights into the use of this resistant species as a Prunus rootstock. P. maackii seedlings planted in 2013 in a heavily infested Armillaria orchard were observed to be growing well, supporting the prior laboratory observation of Armillaria resistance. The sour cherry cultivar ‘Montmorency’ was grafted onto P. maackii seedlings in 2013. These trees are growing well suggesting that sour cherry and P. maackii may be graft compatible. Therefore, future experiments have been initiated to determine if ‘Montmorency’ grafted on P. maackii will result in high yielding trees with acceptable tree and fruit qualities.

    Publications