Amy Iezzoni

Amy Iezzoni

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Department of Horticulture




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Joined Department

September 1, 1981


80% Research
20% Teaching

Other Projects

RosBREED Project (Co-Lead;

Dr. Amy Iezzoni is the Project Director of the USDA-Specialty Crop Research Initiative funded project entitled: “RosBREED: Combining disease resistance and horticultural quality in new rosacous cultivars” ( This ~ $9,500,000 five-year multi-institutional project is dedicated to the genetic improvement of U.S. rosaceous crops by targeted applications of genomes knowledge and tools to accelerate and increase the efficiency of breeding program. 


Ph.D., Plant Breeding and Genetics, University of Wisconsin - Madison, 1981

M.S., Plant Breeding and Genetics, University of Wisconsin - Madison, 1979

B.S., Horticultural Science, North Carolina State University, 1977


Sour Cherry Breeding

The sour cherry (Prunus cerasus) industry in the U.S. is a monoculture of a 400-year-old variety from France called ‘Montmorency’. The goals of the MSU sour cherry breeding program are to develop new cultivars which have superior fruit quality and disease resistance compared to ‘Montmorency’, and will yield consistently over years. To reach these goals, we have an aggressive breeding program which includes approximately 25 acres of seedlings and test sites around the U.S. Currently our disease resistance breeding program involves the introgression of resistance gene(s) for cherry leaf spot (Blumeriella jaapii) resistance from wild Prunus species, P. canescens and P. maackii, into commercially acceptable sour cherry cultivars. The first release from the breeding program, named Balaton®, originated as a landrace variety from Hungary.

Cherry Genetics


Diploid sweet cherry is a classic example of a species exhibiting S-RNase-based gametophytic self-incompatibility. In comparison, individual tetraploid sour cherry selections can be either self-compatible or self-incompatible. Our goal was to understand the genetic control of self-compatibility and self-incompatibility in sour cherry so that new cultivars would be self-compatible and therefore would not need to be planted with a pollinator cultivar.  Our findings indicated that self-compatibility arose in sour cherry from the more ancestral state of self-incompatibility due to the occurrence of self-fertile mutations. So far at least eight self-fertile mutations have been identified and the molecular basis of the mutations has been characterized.   This information is being used in marker-assisted breeding to increase the efficiency of breeding self-compatible cultivars.

Fruit Quality Traits

We have a long standing interest in the genetic control of fruit quality traits in both sweet and sour cherry. Our research strategy is to identify major loci (quantitative trait loci, QTL) that control fruit quality traits that have been altered during domestication. Our initial focus was on the genetic control of fruit size. Anatomical studies indicate that the fruit of a domesticated sweet cherry is larger than the fruit of a wild sweet cherry solely due to an increase in cell number, not cell size. A cell number regulator gene family was characterized in cherry where two of the genes co-locate with fruit size QTLs. This suggests that an increase in fruit size associated with domestication may, in part, be due to an increase in cell division in the fleshy fruit tissue (i.e., mesocarp).  Research is ongoing to understand the genetic control of other fruit quality traits such as fruit firmness and attachment of the fruit to the pit.

Bloom time

One out of every three years, cherry yields in Michigan are significantly reduced by spring freeze damage. New cultivars that bloom later in the spring would have a reduced likelihood of spring freeze damage and therefore crop loss. Fortunately sour cherry germplasm collected in Russia exhibits extremely late bloom time.  Major loci have been identified that control bloom time; and, the late blooming alleles at these loci appear to act in an additive manner suggesting that breeding sour cherries with very late bloom time is a realistic goal.  Our current objective is to find-map these bloom time QTL regions identified as a prelude to candidate gene analysis.

Cherry leaf spot

‘Montmorency’ is extremely susceptible to cherry leaf spot caused by the fungus Blumeriella jaapii. When not properly controlled, cherry leaf spot can cause leaf chlorosis and premature defoliation resulting in fruit that is poorly colored, low in soluble solids, and softer than fruit on healthy trees.  Fortunately resistance and tolerance to cherry leaf spot have been found in diploid cherry species and is being combined into new cultivars.  To date, one major locus controlling cherry leaf spot resistance has been identified and research is currently in progress with the goal of identifying other loci responsible for the resistant and tolerant reactions.

Sweet cherry rootstock selection

Five precocious dwarfing rootstocks were selected from the MSU cherry germplasm collection. All five MSU rootstocks significantly reduce tree size compared to standard seedling rootstocks and fruit production occurs by year three, two years earlier than with a standard production system.  These rootstocks are currently being tested for sweet cherry using ultra-high density trellised production systems and for tart cherry using an over-the-row harvesting production system.

Cherry rootstocks are also being sought that are resistant to the soilborne 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.  Prunus germplasm is currently being screened to search for a source of Armillaria resistance.


  • Calle A, Cai L, Iezzoni A, Wunsch A. 2020. Genetic dissection of bloom time in low chilling sweet cherry (Prunus avium L.) using a multi-family QTL approach. Front. Plant Sci. 10: 3389.

  • Aranzana MJ, Decroocq V, Dirlewanger E, Eduardo I, Gao Z, Gasic K, Iezzoni A, Jung S, Peace C, Prieto U, Tao R, Verde I, Abbott A, Arus P. 2019. Prunus genetics and applications after de novo genome sequencing: Achievements and Prospects. Horticultural Research 6, Article number 58.

  • Cai L, Quero-Garcia J, Barreneche T, Dirlewanger E, Saski C, Iezzoni A. 2019. A fruit firmness QTL identified on linkage group 4 in sweet cherry (Prunus avium L.) is associated with domesticated and bred germplasm. Scientific Reports 9, Article number: 5008.

  • Calle A, Cai L, Iezzoni A, Wunsch A. 2009. High-density linkage maps constructed in sweet cherry (Prunus avium L.) using cross- and self-pollination populations reveal chromosomal homozygosity in inbred families and non-syntenic regions with the peach genome. Tree Genet Genome 14:37

  • Calle A, Cai L, Iezzoni A, Wunsch A. 2019. Construction of a high density SNP marker linkage map of ‘Vic’ × ‘Cristobalina’ in sweet cherry. Acta Horticulturae 1235:55-60.

  • Hardner C, Peace C, Quero-Garcia J, Vanderzande S, Giovannini D, Barreneche T, Campoy JA, Charlot G, Liverani A, Oraguzie N, Villamil-Castro M, Cai L, Ordidge M, Wünsch A, Sotiropoulos T, Kazantzis K, Patocchi A, Perren S, Graetz D, Iezzoni A. 2019. Building an international collaboration to collate historical data for the study of genomic performance by environment interaction. Acta Horticulturae 1235:47-54.

  • Quero-Garcia J, Camboy JA, Barreneche T, Le Dantec L, Wenden B, Fouche M, Dirlewanger E, Silva H, Cai L, Iezzoni A. 2019. Present and future of marker-assisted breeding in sweet and sour cherry. Acta Horticulturae 1235:1-14.

  • Vanderzande S, Howard NP, Cai L, Da Silva Linge C, Antanaviciute L, Bink MCAM, Kruisselbrink JW, Bassil N, Gasic K, Iezzoni A, Van de Weg E, Peace C. 2019.  High-quality, genome-wide SNP genotypic data for pedigreed germplasm of the diploid outbreeding species apple, peach, and sweet cherry through a common workflow. PLOS ONE 14(6); e0210928.

  • Piaskowski J, Hardner C, Cai L, Zhao Y, Iezzoni Y, Peace C. 2018. Genomic heritability estimates in sweet cherry reveal non-additive genetic variance is relevant for industry-prioritized traits. BMC Genetics 19:23.

  • Cai L, Stegmeir T, Sebolt A, Zheng C, Bink M, Iezzoni A. 2018. Identification of bloom date QTLs and haplotype analysis in tetraploid sour cherry (Prunus cerasus). Tree Genetics and Genomes 14:22.

  • Iezzoni A, Peace C, Main D, Bassil N, Coe M, Finn C, Gasic K, Luby J, Hokanson S, McFerson J, Norelli J, Olmstead M, Whitaker V, Yue C. 2017. RosBREED 2: Progress and future plans to enable DNA-informed breeding in the Rosaceae. Acta Hortic. 1172: 115-118.

  • Andersen KL, Sebolt AM, Sundin GW, and Iezzoni AF. 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 67: 682-691.

  • Cai L, Voorrips RE, van de Weg E, Peace C, and Iezzoni A. 2017. Genetic structure of a QTL hotspot on chromosome 2 in sweet cherry indicates positive selection for favorable haplotypes. Molecular Breeding 37:85.

  • Quero-García J, Iezzoni A, Puławska J, and Lang, G. 2017. Cherries: Botany, Production and Uses. CAB International, Wallingford, UK.

  • Stegmeir T, Cai L, Basundari RA, Sebolt AM, and Iezzoni AF. 2015. A DNA test for fruit flesh color in tetraploid sour cherry (Prunus cerasus L.). Mol Breeding 35:149

  • Aguiar B, Vieira J, Cunha AE, Fonseca NA, Iezzoni A, van Nocker S, Vieira CP. 2015. Convergent evolution at the gametophytic self-incompatibility system in Malus and Prunus. PLoS ONE 10(5):e0126138

  • Bassil N, Davis T, Zhang H, Ficklin S, Mittmann M, Webster T, Mahoney L, Wood D, Alperin E, Rosyara U, Putten H, Monfort A, Sargent D, Amaya I, Denoyes B, Bianco L, van Dijk T, Pirani A, Iezzoni A, Main D, Peace C, Yang Y, Whitaker V, Verma S, Bellon L, Brew F, Herrera R, van de Weg E. 2015. Development and preliminary evaluation of a 90 K Axiom® SNP array for the allo-octoploid cultivated strawberry Fragaria × BMC Genomics 16:155 doi:10.1186/s12864-015-1310-1

  • Yue C, Gallardo RK, Luby J, Rihn A, McFerson J, McCracken V, Gradziel T, Gasic K, Reighard G, Clark J, Weebadde C, Sebolt A, Iezzoni A. 2014. An investigation of United States peach fruit producers trait prioritization-evidence from audience clicker surveys. HortScience 49(10):1309-1314.

  • Chavoshi M, Watkins C, Oraguzie B, Zhao Y, Iezzoni A, Oraguzie N. 2014. Phenotyping  protocol for sweetcherry (Prunus avium L.) to facilitate an understanding of trait inheritance. J. Amer. Pom. Soc. 68(3):125–134.

  • Stegmeir T, Schuster M, Sebolt A, Rosyara U, Sundin GS, and Iezzoni A. 2014. Cherry leaf spot resistance in cherry (Prunus) is associated with a quantitative trait locus on linkage group 4 inherited from P. canescens. Mol Breeding 34(3): 927-935.

  • Mathey MM, Mookerjee S, Mahoney L, Finn CE, Hancock JF, Serce S, Davis T, Stewart P, Whitaker VM, Jamieson AR, Bassil NV, Amaya I, Denoyes B, Hummer KE, Sargent D, van de Weg E, Iezzoni A. 2014.  Using General and Specific Combining Ability to Further Advance Strawberry (Fragaria sp.) Breeding. Acta Hort. 1049:193-200.

  • Peace CP, Luby JJ, van de Weg WE, Bink MCAM, Iezzoni AF. 2014 A strategy for developing representativegermplasm sets for systematic QTL validation, demonstrated for apple, peach, and sweet cherry. Tree Genet. Genome DOI 10.1007/s11295-014-0788-z

  • Yue C, Gallardo RK, Luby J, Katare B, Rihn A, McFerson J, McCracken V, Whitaker V, Finn C, Hancock J, Weebadde C, Sebolt A, Iezzoni A. 2014. An evaluation of U.S. strawberry producers trait prioritization: Evidence from audience surveys. HortScience 49 (2):188-193.

  • Rosyara U, Sebolt A, Peace C, and Iezzoni A. 2014. Identification of the Paternal Parent of ‘Bing’ Sweet Cherry and Confirmation of Descendants Using Single Nucleotide Polymorphism Markers. J. of Amer. Soc. of Hort. Sci. 139(2): 148-156.

  • Stegmeir T, Sebolt A, and Iezzoni A. 2013. Phenotyping protocol for sour cherry (Prunus cerasus L.) to enable a better understanding of trait inheritance. J. of Amer. Pomol. Soc. 68(1): 40-47.

  • Rosyara U, Bink CAM, van de Weg E, Zhang G, Wang D, Sebolt A, Dirlewanger E, Quero-Garcia J, Schuster M, Iezzoni A. 2013. Fruit size QTL identification and the prediction of parental QTL genotypes and breeding values in multiple pedigreed populations of sweet cherry. Molecular Breeding 32:875-887

  • Mathey MM, Mookerjee S, Gündüz K, Hancock JF, Iezzoni AF, Mahoney LL, Davis TM, Bassil NV, Hummer KE, Stewart PJ, Whitaker VM, Sargent DJ, Denoyes B, Amaya I, van de Weg E, and Finn CE. 2013. Large-scale standardized phenotyping of strawberry in RosBREED. J. of Amer. Pomol. Soc. 67(4) 205.

  • Yue C, Gallardo RK, Luby J, Rihn A, McFerson J, McCracken V, Bedford D, Brown S, Evans K, Weebadde C, Sebolt A, Iezzoni A. 2013. An Investigation of U.S. Apple Producers' Trait Prioritization-Evidence from Audience Surveys. Hortscience 48(11): 1378-1384.

  • Klagges C, Campoy JA, Quero-Garcia J, Guzman A, Mansur L, Gratacos E, Silva H, Rosyara, UR, Iezzoni A, Meisel LA, Dirlewanger E. 2013. Construction and comparative analyses of highly dense linkage maps of two sweet cherry intra-specific progenies of commercial cultivars. PLoS ONE 8(1): e54743.

  • De Franceshi P, Stegmeir T, Cabrera A, van der Knapp E, Rosyara U, Sebolt A, Dondini L, Dirlewanger E, Quero-Garcia J, Campoy J, and Iezzoni A. 2013.  Cell number regulator genes in Prunus provide candidate genes for the control of fruit size in sweet and sour cherry. Molecular Breeding 32:311-326.

  • Evans K, Luby J, Brown S, Clark M, Guan Y, Orcheski B, Schmitz C, Peace C, van de Weg E, and Iezzoni A. 2012. Large-scale standardized phenotyping of apple in RosBREED. ISHS Postharvest Unlimited. Acta Horticulturae 945: 233-238.

  • Peace C, Bassil N, Main D, Ficklin S, Rosyara UR, Stegmeir T, Sebolt A, Gilmore B, Lawley C, Mockler TC, Bryant DW, Wilhelm L, Iezzoni A. 2012. Development and evaluation of a genome-wide 6K SNP array for diploid sweet cherry and tetraploid sour cherry. PLoS One 7(12): e48305.

  • Verde I, Bassil N, Scalabrin S, Gilmore B, Lawley CT, Gasic K, Micheletti D, Rosyara UR, Cattonaro F, Vendramin E, Main D, Aramini V, Blas AL, Mockler TC, Bryant DW, Wilhelm L, Troggio M, Sosinski B, Aranzana MJ, Arus P, Iezzoni A, Morgante M, Peace C.  2012 Development and evaluation of a 9K SNP array for peach by internationally coordinated SNP detection and validation in breeding germplasm. PLoS ONE 7(4): e35668.

  • Chagne D, Crowhurst RN, Troggio M, Davey MW, Gilmore B, Lawley C, Vanderzande S, Hellens RP, Kumar S, Cestaro A, Velasco R, Main D, Rees JD, Iezzoni A, Mockler T, Wilhelm L, van de Weg E, Gardiner SE, Bassil N, Peace C.  2012. Genome-wide SNP detection, validation, and development of an 8K SNP array for apple. PLoS ONE 7(2): e31745.

  • Yue CY, Gallardo RK, McCracken VA, Luby J, McFerson JR, Liu L, Iezzoni A.  2012. Technical and socioeconomic challenges to setting and implementing priorities in North American rosaceous fruit breeding programs. HortScience 47(9): 1320-1327.

  • Cabrera A, Rosyara UR, De Franceschi PSebolt A, Sooriyapathirana SS, Dirlewanger D, Quero-Garcia J, Schuster M, Iezzoni AF, van der Knaap E. 2012. Rosaceae Conserved Orthologous Sequences marker polymorphism in sweet cherry germplasm and construction of a SNP-based map. Tree Genet Genomes 8(2): 237-247.

  • Illa E, Sargent DJ, Girona EL, Bushakra J, Cestaro A, Crowhurst R, Pindo M, Cabrera A, van der Knapp E, Iezzoni A, Gardiner S, Velasco R, Arus P, Chagne D, Troggio M. 2011. Comparative analysis of rosaceous genomes and the reconstruction of a putative ancestral genome for the family. BMC Evolutionary Biology 11:9.

  • Siddiq M, Iezzoni A, Khan A, Breen P, Sebolt A, Dolan K, Ravi R.  2011. Characterization of new tart cherry (Prunus cerasus L.) selections based on fruit quality, total anthocyanins, and antioxidant capacity. Intl. J. Food Properties 14:471-481.

  • Sooriyapathirana SS, Khan A, Sebolt AM, Wang D, Bushakra JM, Lin-Wang K, Allan AC, Gardiner SE, Chagne D, Iezzoni AF.  2010. QTL analysis and candidate gene mapping for skin and flesh color in sweet cherry fruit (Prunus avium L.) Tree Genetics and Genomes 6:821-832.

  • Zhang G, Sebolt AM, Sooriyapathirana SS, Wang D, Bink MCAM, Olmstead JW, Iezzoni AF. 2010.  Fruit size QTL analysis in an F1 population derived from a cross between a domesticated sweet cherry cultivar and a wild forest sweet cherry. Tree Genet Genomes 6:25-36.

  • Lin H, Moghe G, Ouyang S, Iezzoni A, Shiu S-h, Gu X, Buell CR. 2010.  Comparative analyses reveal distinct sets of lineage-specific genes within Arabidopsis thaliana. BMC Evolutionary Biology 10:41.

  • Tsukamoto T, Hauck NR, Tao R, Jiang N, Iezzoni AF.  2010.  Molecular and genetic analysis of four nonfunctional S haplotype variants derived from a common ancestral S haplotype identified in sour cherry (Prunus cerasus L.) Genetics 184:411-427.

  • Tao R, Iezzoni AF. 2010. The S-RNase-based gametophytic self-incompatibility system in Prunus exhibits distinct genetic and molecular features. Scientia Horticulturae 134:423-433.

  • Cabrera A, Kozik A, Howad W, Arus P, Iezzoni AF, van der Knapp E. 2009.  Development and bin mapping of a Rosaceae Conserved Ortholog Set (COS) of markers. BMC Genomics 10:562

  • Prassinos C, Ko J-H, Lang G, Iezzoni AF. 2009.  Rootstock-induced dwarfing in cherries is caused by differential cessation of terminal meristem growth and is triggered by rootstock specific gene regulation.  Tree Physiology 29: 927-936. 

  • Lacis G, Rashal I, Ruisa S, Trajkovski V, Iezzoni AF. 2009. Assessment of genetic diversity of Latvian and Swedish sweet cherry (Prunus avium L.) genetic resources collections by using SSR (microsatellite) markers. Scientia Horticulturae 121(4): 451-457.

  • Gasic K, Han YP, Kertbundit S, Shulaev V, Iezzoni AF, Stover EW, Bell RL, Wisniewski ME, Korban SS. 2009. Characteristics and transferability of new apple EST-derived SSRs to other Rosaceous species. Molecular Breeding 23 (3): 397-411.

  • Sebolt AM, Iezzoni AF. 2009. Utilization of the S-locus in cherry to differentiate among different pollen donors. HortScience 44:1542-1546.

  • Lacis G, Kaufmane E, Rashal I, Trajkovski V, Iezzoni AF. 2008. Identification of self-incompatibility (S) alleles in Latvian and Swedish sweet cherry genetic resources by PCR base typing.  Euphytica 160: 155-163.

  • Tsukamoto T, Tao R, Iezzoni, AF. 2008. PCR markers for mutated S-haplotypes enable discrimination between self-incompatible and self-compatible sour cherry selections. Molecular Breeding 21(1):67-80

  • Olmstead JW, Sebolt AM, Cabrera A, Sooriyapathirana SS, Hammar SIriarte G, Wang D, Chen CY, van der Knaap E, Iezzoni AF. 2008. Construction of an intra-specific sweet cherry (Prunus avium L.) genetic linkage map and synteny analysis with the Prunus reference map. Tree Genet Genomes 4:897-910.

  • Shulaev V, Korban SS, Sosinski B, Abbott AB, Aldwinckle HS, Folta KM, Iezzoni A, Main D, Arus P, Dandekar AM, Kewers K, Brown SK, Davis TM, Gardiner SE, Veilleux RE. 2008.  Rosaceae genomics - A multiple model solution. Plant Physiology 147: 985-1003.

  • Tsukamoto T, Potter D, Tao R, Vieira CP, Vieira J, Iezzoni AF.  2008. Genetic and molecular characterization of three novel S-haplotypes in sour cherry (Prunus cerasus L.). J. Experimental Botany 59: 3169-3185.

  • Olmstead JW, Iezzoni AF, Whiting MD.  2007. Genotypic differences in sweet cherry fruit size are primarily a function of cell number. J Amer Soc Hort Sci 132(5): 697-703.

  • Tsukamoto T, Hauck NR, Tao R, Jiang N, Iezzoni AF. 2006.  Molecular characterization of three non-functionalS-haplotypes in sour cherry (Prunus cerasus). Plant Molecular Biology 62:371-383.

  • Hauck NR, Yamane H, Tao R, Iezzoni A. 2006. Accumulation of non-functional S-haplotypes results in the breakdown of gametophytic self-incompatibility in tetraploid cherry. Genetics 172: 1191-1198.

  • Hauck NR, Ikeda K, Tao R, Iezzoni AF. 2006. The mutated S1-haplotype in sour cherry has an altered S-haplotype specific F-box protein gene. J Hered. 97: 514-520.

  • Kacar YA, MS Cetiner, C Cantini, Iezzoni AF. 2006. Simple sequence repeat (SSR) markers differentiate Turkish sour cherry germplasm. Jour Amer  Pomological Soc. 60 (3):136-143.

  • Iezzoni AF. 2005.  Acquiring cherry germplasm from Central and Eastern Europe. HortScience 40(2): 304-308.

  • Ikeda K, Ushijima K, Yamane H, Tao R, Hauck NR, Sebolt AM, Iezzoni AF.  2005.  Linkage and physical distances between the S-haplotype S-RNase and SFB genes in sweet cherry. Sexual Plant Reproduction 17: 289-296.

  • Kacar YA, Iezzoni A, Cetiner S. 2005.  Sweet cherry cultivar identification by using SSR markers. Journal of Biological Sciences 5(5): 616-619.

  • Ikeda K, Watari A, Ushijima K, Yamane H, Tao R, Hauck NR, Iezzoni AF. 2004.  Molecular markers for the self-compatible S4'-haplotype, a pollen part mutant in sweet cherry (Prunus avium L.). J. Amer. Soc. Hort. Sci. 129 (5): 724-728.

  • Ushijami K, Yamane H, Watari A, Kakehi E, Ikeda K, Hauck NR, Iezzoni AF, Tao R. 2004.  The S haplotype-specific F-box protein gene, SFB, is defective in self-compatible haplotypes of Prunus avium and P. mume.  Plant Journal 39: 573-586.

  • Aranzana MJ, Pineda A, Cosson P, Dirlewanger E, Ascasibar J, Testolin R, Abbott A,  King GJ, Iezzoni AF, Arus P. 2003.  A set of simple-sequence repeat (SSR) markers covering the Prunus genome. Theor. Appl. Genet. 106: 819-825.

  • Wharton PS, Iezzoni AF, Jones AL. 2003. Screening cherry germplasm for resistance to cherry leaf spot. Plant Disease 87 (5): 471-477.

  • Yamane H, Ikeda K, Hauck NR, Iezzoni AF, Tao R. 2003. Self-incompatibility (S) locus region of the mutated S6-haplotype of sour cherry (Prunus cerasus) contains functional pollen S allele and non-functional pistil S-allele. J. Experimental Botany 54: 2431-2437.