About

Mark Earl Sorrells is a professor in the School of Integrative Plant Science, Plant Breeding and Genetics Section at Cornell University. He is also an Atkinson Center for a Sustainable Future Fellow and a Cornell Institute for Food Systems Fellow. His research program has a long history of over 100 years through the Cornell Small Grains Project, focusing on developing innovative approaches to crop improvement. His work utilizes technologies such as molecular genetics, physiology, pathology, and breeding to develop superior crop varieties suitable for both conventional and organic cropping systems. Sorrells collaborates with plant breeders and geneticists worldwide, including international centers, on projects involving molecular markers to assess genetic relationships, construct linkage maps, and clone genes. His basic research emphasizes comparative genomics, association mapping, allele characterization, and genomic selection methods. His projects include mapping, cloning, and characterizing genes related to traits such as preharvest sprouting resistance, milling and baking quality, kernel size and shape, stem rust resistance, and nutritional quality. Additionally, he has evaluated ancient and specialty grains under organic management, contributing significantly to the field of crop genetics and breeding.

Research topics

• Biology
• Genetics
• Botany
• Agronomy
• Biotechnology
• Computational biology
• Evolutionary biology

Selected publications

• The <i>SD1</i> locus affects primary seed dormancy in winter malting barley

  The Plant Genome · 2026-04-02

  articleOpen accessSenior authorCorresponding

  Preharvest sprouting (PHS) resistance and seed dormancy are key targets for malting barley (Hordeum vulgare L.) in environments with a high probability of rain events at harvest. Characterization has been limited in winter malting barley compared to spring malting barley in the United States. We used a modified half-sibling winter malting barley breeding population to map PHS at maturity and germination traits during after-ripening to identify marker associations with dormancy and rate of dormancy loss. Seed dormancy locus 1 (SD1) on chromosome 5H has been identified as an H. vulgare L. alanine aminotransferase (HvAlaAT) gene. The SD1 locus was significantly associated with the rate of primary seed dormancy loss in the winter malting barley population, and additional quantitative trait loci (QTLs) for PHS resistance and seed dormancy were identified. Identified markers for HvAlaAT alleles and other QTL for seed dormancy can provide greater precision for selecting lines that have high PHS resistance but short dormancy periods to produce high-quality malt.

  PublisherDOI

• The value and broader impacts of agricultural and environmental scientific meetings

  Agricultural & Environmental Letters · 2025-05-22 · 1 citations

  articleOpen access

  Abstract The socioeconomic value of content presented at the ASA‐CSSA‐SSSA (where ASA‐CSSA‐SSSA is American Society of Agronomy–Crop Science Society of America–Soil Science Society of America) Annual Meetings from 2014 to 2023 is estimated at $64.2 billion and is presented in this commentary as a thought exercise, highlighting the potential scale of research dissemination in scientific meetings. Scientific meetings are instrumental for propelling the quality and advancement of research via fostering timely feedback, knowledge dissemination, fresh perspectives, stimulation for networking and new collaborations, preparing scientists for public engagement, and addressing contemporary challenges of cultural accessibility and opportunity. Additionally, the broader impacts include near‐term benefits to agricultural and environmental scientists that can transform careers and perspectives on the world, especially for students and early career members. The benefits from these impacts on scientists are then anticipated to propagate into broader and longer term positive impacts on humanity worldwide. In this commentary, we offer the above as a provocation to spark peer discussion on evaluating scientific meetings’ contributions, alongside a working list of broader impacts to inspire philosophical and methodological innovations for quantifying their value.

  PublisherOA PDFDOI

• Field trial analyses of wheat and cassava benefit from spatial correction

  2025-06-04

  preprintOpen access

  Spatial variation is a major source of error in agricultural field experiments affecting genotype performance prediction. Implementing statistical models that account for spatial effects can improve the prediction of genotype performance. This study evaluated the impact of the B-spline spatial correction method on the estimation of genetic parameters and AIC values in two distinct crops – wheat and cassava – using four models: Block, Block + Spatial, Block + Marker, and Block + Marker + Spatial. Analyses were performed on data from 136 and 68 trials obtained from the T3/WheatCAP and Cassavabase databases, respectively. The results demonstrated that correcting for spatial variation, regardless of marker information, increased the heritability estimate of grain yield, test weight, plant height, powdery mildew, stripe rust, and bacterial streak disease in wheat. Similar increases were observed in cassava for dry matter content, dry yield, and plant height. However, no increase was observed for cassava mosaic disease or bacterial blight. Models incorporating spatial correction in both crops consistently provided the best fit based on AIC values across all traits in wheat and cassava. These results were consistent whether or not marker effects were fitted in the models. This showed the importance of spatial correction in field experiment analysis.

  PublisherOA PDFDOI

• Whole-genome resequencing of the wild barley diversity collection: a resource for identifying and exploiting genetic variation for cultivated barley improvement

  G3 Genes Genomes Genetics · 2025-11-08 · 3 citations

  articleOpen access

  To exploit allelic variation in Hordeum vulgare subsp. spontaneum, the Wild Barley Diversity Collection was subjected to paired-end Illumina sequencing at ∼9 × depth and evaluated for several agronomic traits. We discovered 240.2 million single nucleotide polymorphisms (SNPs) after alignment to the Morex V3 assembly and 24.4 million short (1 to 50 bp) insertions and deletions. A genome-wide association study of lemma color identified one marker-trait association (MTA) on chromosome 1H close to HvBlp, the cloned gene controlling black lemma. Four MTAs were identified for seedling stem rust resistance, including 2 novel loci on chromosomes 1H and 6H and one co-locating to the complex RMRL1-RMRL2 locus on 5H. The whole-genome sequence data described herein will facilitate the identification and utilization of new alleles for barley improvement.

  PublisherOA PDFDOI

• Response to plant defense elicitation is genotype and context dependent in diverse oat ( <i>Avena sativa</i> L.) germplasm

  Journal of Experimental Botany · 2025-07-10 · 1 citations

  article

  Pests and pathogens contribute to substantial crop yield losses, and these losses are predicted to be exacerbated by varying and new pest pressures associated with climate change. As such, characterizing variation in immune responses is critical for developing new plant breeding approaches for multiple biotic stress resilience. We thus tested the extent to which plants vary in responsiveness to defense elicitation and associated growth-defense trade-offs, and how these responses depended on field and pathogen conditions. Using a panel of >250 spring oat (Avena sativa L.) genotypes, we evaluated phenotypic and genetic variation in defense elicitation by measuring avenanthramides, specialized defensive metabolites, and disease resistance, as well as yield and growth traits. We found that defense elicitation increased the concentration of defensive avenanthramides across trials, and reduced the severity of crown rust and Fusarium head blight. There was substantial genetic variation in responses, and also genotype-by-elicitation state interactions in field trials. While plant growth was reduced in some trials, there were no loci identified by genome-wide association mapping for either growth or defense regulation. These results demonstrate that targeting variation in regulation of defense can contribute to breeding for resilient crops, and that breeders could develop genotypes with reduced growth-defense trade-offs.

  PublisherDOI

• Reaction of Winter Malting Barley Cultivars and Breeding Lines to Foliar Diseases in New York, 2024

  Plant Health Progress · 2025-01-01

  articleSenior author

  Foliar diseases of winter malting barley ( Hordeum vulgare) include scald ( Rhynchosporium commune), Stagonospora nodorum blotch ( Parastagonospora nodorum), spot blotch ( Bipolaris sorokiniana), and net blotch ( Pyrenophora teres). Symptoms include water-soaked to necrotic lesions with a distinctive brown margin (scald); yellowish to tan-brown, oval or lens-shaped lesions (Stagonospora nodorum blotch); small circular dark brown lesions with a chlorotic zone (spot blotch and spot form net blotch); and small dark brown lesions that develop into a net-like pattern (net form net blotch). This report evaluates a collection of 8 cultivars and 28 breeding lines for reaction to the foliar diseases. The trial was conducted in two field sites in Tompkins County near Ithaca, NY, in 2024. Results indicate differentiation of reaction to natural inoculum of the foliar diseases and identified lines with resistance to scald, Stagonospora nodorum blotch, and net/spot blotches that may be useful for breeding for foliar disease resistance.

  PublisherDOI

• Reaction of Spring Malting Barley Cultivars and Breeding Lines to Foliar Diseases in New York, 2024

  Plant Health Progress · 2025-01-01

  articleSenior author

  Foliar diseases of spring malting barley ( Hordeum vulgare) include scald ( Rhynchosporium commune) and leaf blotches, such as spot blotch ( Bipolaris sorokiniana), net blotch ( Pyrenophora teres), and Stagonospora nodorum blotch ( Parastagonospora nodorum). Symptoms include water-soaked to necrotic lesions with a distinctive brown margin (scald), small circular dark brown lesions with a chlorotic zone (spot blotch and spot form net blotch), small dark brown lesions that develop into a net-like pattern (net form net blotch), and yellowish to tan-brown, oval or lens-shaped lesions (Stagonospora nodorum blotch). A collection of 8 cultivars and 28 breeding lines are reported for reaction to the foliar diseases across two field sites in Tompkins County near Ithaca, NY, in 2024. Differentiation of reaction to natural inoculum of the foliar diseases identified lines with resistance to leaf blotches as well as scald that may be useful for breeding for foliar disease resistance.

  PublisherDOI

• Heterosis and hybrid breeding

  Theoretical and Applied Genetics · 2025-03-11 · 5 citations

  editorialOpen access
  PublisherOA PDFDOI

• Organic small grain production in the Upper Midwest and Northeast: Challenges and lessons learned

  Agronomy Journal · 2024-08-22 · 4 citations

  articleOpen accessSenior author

  Abstract Small grains provide agronomic benefits that are critical to the success of organic production, and opportunities within local food movements create expanded markets for small grains. However, diversifying rotations with small grains can present challenges related to production, infrastructure, and markets. Here, we draw upon over two decades of integrated research and Extension efforts to support organic small grain production in the Upper Midwest, Northeast, and other regions of the United States where these crops are underutilized. Lessons learned have led to the development of guiding principles for a systems‐level approach to support regional organic small grain production. Forming innovative partnerships between farmers, researchers, and end users is critical. This enables research, production, and markets to adjust to local needs, adapt to available infrastructure, and foster local grain economies. The key research challenges that lie ahead are also discussed, especially adapting organic grain production practices to regional conditions and changing climates. The systems‐level approach to organic small grain research highlighted here will increase the success and resilience of organic farms across the United States and expand the adoption of organic small grain production.

  PublisherOA PDFDOI

• Genotype × environment interactions of organic winter naked barley for agronomic, disease, and grain quality traits

  Crop Science · 2024-02-06 · 7 citations

  articleOpen accessSenior authorCorresponding

  Abstract The modeling of genotype × environment interactions (GEI) is important to understand how new crops perform in different environments and management systems. Naked barley ( Hordeum vulgare L.) is a type of barley where the hull threshes freely from the grain and can be used for multiple end uses, including food, malt, and animal feed. We examined the performance of a winter naked barley trial grown in organic conditions across three regions and 3 years in northern latitude regions of the United States. We recorded yield, test weight, heading date, plant height, threshability, winter survival, barley stripe rust ( Puccinia striiformis f. sp. hordei Westend), barley scald ( Rhynchosporium commune Zaffarano, McDonald and Linde sp. nov), and spot blotch ( Cochliobolus sativus , anamorph Bipolaris sorokiniana (S. Ito &amp; Kurib.). Barley stripe rust, plant height, heading date, preharvest sprouting, and threshability had high heritability and low GEI. Grain yield, test weight, scald, and winter survival had high GEI and were analyzed using the additive main effect and multiplicative interaction (AMMI) model, genotype plus GEI biplot (GGE), and Finlay–Wilkinson (FW) stability analysis. The environmental patterns explained by the AMMI and GGE models indicated that selection for high GEI traits should occur within target environments and across multiple years within the target environments. Environmental groups were separated by Oregon as the first group and Wisconsin and New York as the second group.

  PublisherOA PDFDOI

Frequent coauthors

• Jean‐Luc Jannink

  Cornell University

  141 shared

• Shiaoman Chao

  Edward T. Schafer Agricultural Research Center

  65 shared

• James A. Anderson

  University of Minnesota

  64 shared

• Jorge Dubcovsky

  54 shared

• Eduard Akhunov

  Kansas State University

  47 shared

• Gerard R. Lazo

  Western Regional Research Center

  44 shared

• Jan Dvořák

  41 shared

• Shahryar F. Kianian

  Cereal Disease Laboratory

  40 shared

Awards & honors

• Crop Science Society of America Named to a list of the world…
• Ron Phillips Plant Genetics Lectureship (2017)
• Crop Science Society of America Outstanding Research Award (…