Source: UNIVERSITY OF CALIFORNIA, DAVIS submitted to
GENETIC CONTROL OF POD TRAITS DISTINGUISHING SNAP BEANS FROM DRY BEANS, AND PRE-BREEDING TO ENHANCE THEIR GENETIC STABILITY
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1030596
Grant No.
2023-67013-40001
Cumulative Award Amt.
$649,480.00
Proposal No.
2022-10300
Multistate No.
(N/A)
Project Start Date
Sep 15, 2023
Project End Date
Sep 14, 2027
Grant Year
2023
Program Code
[A1141]- Plant Health and Production and Plant Products: Plant Breeding for Agricultural Production
Project Director
Parker, T.
Recipient Organization
UNIVERSITY OF CALIFORNIA, DAVIS
410 MRAK HALL
DAVIS,CA 95616-8671
Performing Department
(N/A)
Non Technical Summary
Snap beans, also known as green beans, differ from their dry bean relatives in several critical pod quality traits, which are genetically and environmentally unstable. In this project, we seek to understand the genetic basis of this variation and take the first steps towards reducing production costs and promoting the stability of high culinary quality in this important vegetable crop.Common bean (Phaseolus vulgaris) is produced for two major market categories in the United States, 1) "dry" beans grown for protein-rich seeds, and 2) "snap" or "green" beans grown for edible pods as vegetables. These two classes are distinguished by several major differences related to pod structure and development. These include pod shape (flat vs. round), pod wall fiber (tough vs. tender), and pod suture "strings" (stringy vs. non-stringy). Commercial snap beans must have round cross sections and very low levels of pod fiber to be commercially accepted.Intriguingly, these traits spontaneouslyrevert from the snap bean state to the ancestral dry bean form, at a rate of approximately 1%. This reversion is heritable, and the seeds from these plants will also form the undesirable traits. This reversion makes it critical for each plant in seed production fields to be individually checked to remove ("rogue") revertants, which costs $50,000 per variety per company per yearto seed producers. Beyond this, pod fiber deposition in many snap beans is greatly exacerbated by heat and drought, but the Ts (Temperature sensitive) genehas never been mapped genetically. Harvested snap beans with highfiberare subject to market rejection, making the identification of this genetic variationimportant in the context of climate change.Here, we propose to explore the genetic and developmental basis of each trait and its instability by conducting Genome-Wide Association Studies (GWAS), extensive whole genome sequencing and diversity analyses, fluorescence microscopy, and RT-qPCR. These studies will in part take advantage of the highly controlled experimental system of revertant / non-revertant pairs of identical genetic background. Finally, we will use our new genetic understanding of the developmental genetics of pod stability to select genetic stocks with higher levels of stability in otherwise unstable types of commercial importance. The results of this study will reduce seed production costs, improve product quality, promoteclimate change resilience, and greatly facilitate breeding in a nutritious and broadly consumed vegetable crop.
Animal Health Component
15%
Research Effort Categories
Basic
70%
Applied
15%
Developmental
15%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2011411108060%
2021411108120%
2041411108120%
Knowledge Area
204 - Plant Product Quality and Utility (Preharvest); 201 - Plant Genome, Genetics, and Genetic Mechanisms; 202 - Plant Genetic Resources;

Subject Of Investigation
1411 - Beans (fresh, fresh-processed);

Field Of Science
1081 - Breeding; 1080 - Genetics;
Goals / Objectives
Project Goals: To understand the genetic architecture underlying the unstable pod traits distinguishing snap beans from dry beans, and initiate a pre-breeding program to reduce their genetic instability.Snap beans are a major commodity, and are distinguished from other beans by pod traits such as lack of pod wall fiber, round pod cross-section, and lack of suture strings. These traits all frequently revert to the wild-type characteristics, and show environmental instability. In this project, we seek to better understand the genetic factors responsible for these traits. We then hope to identify the causes of genetic reversion and environmental instability. Finally, we plan to use the knowledge gained to develop new pre-breeding lines which maintain high pod quality across environments, and show greater resistance to reversion.Objective 1. Use cutting-edge genotyping and sequencing approaches to understand the genetic basis of environmental and genetic instability in contrasting environments.Generate high-density genotype data on 280 members of the Snap bean Association Panel (SnAP).Phenotype pod traits in the SnAP diversity panel and 200 photoperiod-insensitive dry beans of the Andean Diversity Panel in cool environments (winter greenhouse) and warm environments (summer field trials), to characterize pod traits and identify patterns of genetic reversion and genotype x environment interaction.Genetically map pod traits in the SnAP and ADP populations through Genome-Wide Association StudiesUse PacBio Hifi sequencing and Bionano mapping to generate full genome assemblies (chromosome-scale scaffolds) of one revertant / non-revertant pair for each pod trait, to identify structural variation responsible for pod instability and reversion.Validate results with Illumina Whole Genome Sequencing of 48 lines with variable stabilityDetermine patterns of population structure and understand patterns of historical trait evolution through phylogenetic tree construction, haplotype gene network mapping, and comparison with phenotypic character state changesObjective 2. Characterize the developmental basis of pod quality traitsUnderstand the anatomical basis of pod variation and stability with fluorescence microscopy of revertant / non-revertant and environmentally variable pairsUnderstand transcriptional differences which may underlie pod variation using RT-qPCR of candidate genes in revertant / non-revertant pairsObjective 3. Develop genetic stocks with improved environmental stability and reduced rates of genetic reversionConduct half-diallel crossing blocks between commercial varieties with contrasting levels pod trait stabilityBased on phenotyping results in the field and greenhouse, select families to advance to BC2F3Genotype a plate of 96 BC2F3 breeding lines to identify those which have inherited stable alleles from donor parents
Project Methods
EffortsObjective 1.Activity 1.1: In Fall 2023, we will generate a SNP data set for 280 members of the SnAP population using the same methods applied for the ADP, to allow for full integration of the populations into one large composite ADP/SnAP population of approximately 850 lines. The SNP genotyping involved will consist of a low-pass sequencing approach. Dark-grown leaves of each variety will be sent to the Hudson Alpha Institute for Biotechnology (Huntsville, AL) for sequencing and SNP profiling.Activity 1.2: The 280 genotyped members of the SnAP population and 200 accessions from the Andean diversity panel will be grown out in the greenhouse and field to evaluate pod characteristics in varying environments. Greenhouse screenings will include three plants of each entry. Field plots in OSU will consist of a single 15' row planted with 60 seeds. Field plots in Davis will include a pair of 15' rows planted with 120 seeds. Field plantings in OSU and Davis will follow an augmented design. For standard pod phenotyping in the field and greenhouse, 10 pods of each variety will be sampled and scored. Phenotyping will be conducted for pod string and wall fiber based on a 0-10 scale. Pod length, pod width, pod height, and pod wall thickness will be measured with calipers. Replicated controls will include varieties which have extremely high or low pod stability (see Activities 1.5, 3.1, 3.2). For these varieties, at least one pod of every plant in the field will be screened for reversion of pod shape, pod wall fiber, and pod wall fiber, and frequency of reversion for each trait in each accession will be recorded. Field and greenhouse screenings will each be replicated for two years.Activity 1.3: Multi-environment data will be used to conduct Genome-Wide Association Studies (GWAS) for all evaluated traits. GWAS will be conducted in Tassel according to methods of Parker et al. 2020. GWAS will be based on SNP data from Activity 1.1, phenotype data from Activity 1.2, and the first five principal components of the genetic data as a control for population structure. SNPs with a minor allele frequency < 0.05 will be filtered before GWAS, and significance will be determined based on a Bonferroni correction for a false discovery rate of 0.05. Information such as gene ontology terms, Panther classifications, and transcriptional data will be mined for genes near GWAS peaks using Phytomine and the Legume Information System to identify candidate genes.Activity 1.4: For each pod trait, one snap / revertant isogenic pair will be dark-grown, and chilled leaf samples will be shipped to Histogenetics LLC (Ossining, NY) to conduct PacBio Hifi long-read sequencing, Bionano optical mapping, and scaffolding of the two data types into chromosome-scale hybrid assemblies. The scaffolds will be compared between isogenic pairs at loci significantly associated with traits by using NCBI BLAST, with a particular focus on candidate genes identified in Activity 1.3. Repeats, other indels, and inversions will be identified based on dotplots of the alignments. Indels not aligning well between isogenic pairs will be BLASTed against the full NCBI nucleotide database to determine their identity, for example to identify similarity with known transposable element families.Activity 1.5: A panel of 48 accessions will be genetically characterized using Illumina Whole Genome Sequencing (WGS) to validate the role of sequence variation identified in Activity 1.4. These will include no fewer than 16 revertant / non-revertant isogenic pairs, and up to 32 diverse materials with variable pod phenotypes and variable pod stability (see also Activity 3.1). Genotyped plants will be dark-grown and DNA will be extracted and its quality checked according to the procedure of Activity 1.1. This sequencing will be conducted at a depth of 15x by the UC Davis Genome Center. Sequences will be aligned to reference bean genomes using NGSEP4. WGS alignments from NGSEP will be screened using the Integrated Genomics Viewer. For SNPs or short repeats, the sequence data at sites of interest will be directly compared, while for large indels such as transposons, reads will be screened for those spanning the indel junctures. For large tandem repeats of variable number, WGS read depth will be used to determine repeat number between accessions.Activity 1.6: SNP data from Activity 1.1 will be used to better understand genetic patterns of selection and evolution. First, neighbor-joining trees will be developed by the parsimony substitution model of TASSEL. Tree graphics will be developed with FigTree version 1.4.0. Character state information from Activity 1.2 will be visualized on the trees to suggest patterns between genetic diversity and pod evolutionary patterns. Signatures of historical selective sweeps will be identified based on the ratio of nucleotide diversity in groups of contrasting pod phenotype (e.g., π [round pod accessions] / π [flat pod accessions]). Finally, whole genome sequencing data from Activities 1.4 and 1.5 will be used to make haplotype networks of putative pod-regulating genes, using the parsimony splits decomposition network analysis method.Objective 2. Activity 2.1: Pods will be harvested from greenhouse-grown plants from isogenic pairs, including types that are revertant and non-revertant for pod wall fiber, as well as types with temperature-sensitive partial string grown at temperatures. These pods will be harvested at 21 days post-anthesis. Sectioning and microscopy will be conducted according to the methods of Lo et al. 2021.Activity 2.2: Pods will be harvested for transcriptional analysis by RT-qPCR at 5 and 21 days post-anthesis. RT-qPCR will be to identify differential expression of candidate genes according to the procedure of Parker et al. (2022).Objective 3.Activity 3.1: Crossing blocks will be mated between 1) at least five varieties with high vs. five varieties with low levels of genetic reversion for multiple pod traits, and 2) at least five varieties with high vs. five varieties with low levels of environmental stability for partial suture fiber. These crosses will result in 25 F1 pools per category (genetic vs. environmental instability), for a total of 50 lines. These will be advanced for further backcrossing.Activity 3.2: The 50 F1 lines derived from Activity 3.1 will be greenhouse-grown and backcrossed to their unstable parents. BC1F1 seed will be harvested, greenhouse-grown (at least ten BC1F1 lines per genotype pairing), and backcrossed again (BC2F1) with the same unstable recurrent parent. For both genetic and environmental components, the two families with the widest disparity in stability will be advanced to the BC2F3 for marker-assisted selection, for a total of four advanced families of 25+ lines each.Activity 3.3: In the BC2F3 generation, we will use the knowledge gained in Activities 1.1-1.6 about the precise genetics associated with pod stability to select families with stable alleles in the genetic background of unstable commercial varieties. 96 plants (24 of each of four selected families) will be genotyped using the shallowing-sequencing approach by Hudson Alpha Institute according to the methods described in Activity 1.1 to identify at least one stable line in each stability class (environmental vs. genetic reversion).Evaluation-Identification of loci associated with unstable pod characteristics-Determination of sequence polymorphisms explaining pod variation-Identification of population genetics and developmental patterns related to pod evolution-Development of multiple sequence-characterized populations-Generation of germplasm with improved pod stability-Results published in scientific and industryjournals-Genetic data made publicly available through NCBI and LIS-Outreach to industry and public through in-person events and online educational content

Progress 09/15/23 to 09/14/24

Outputs
Target Audience:We have made a series of exciting discoveries which we have begun to share, including through scientific publications. Weare also still in the earlier stages of the project and are actively generating data to publish in the future. Target audiences so far have been scientists and breedersin academia and the private sector, such as at seed companies. We have been in direct contact with breeders from several companies, including Syngenta, HM Clause, Seneca Foods, Brotherton Seeds, and Crites, Pop Vriend, and van Waveren, and the University of Embu. We have intentionally only provided limited and private disclosures to them, as we generate data. Our closest collaboration over several years has been with Syngenta, with whom we have privately shared many of our major findings, due to their history of material and knowledge sharing with us. We believe the data will be of considerable commercial interest when it is released. A Record of Invention with the UC Davis Tech Transfer department was in drafting during the reporting period,(submitted after the reporting period). The Record of Invention covered the discovery of multiple alleles for the tender pod trait in snap (green) bean, as well as genetic tests to rapidly screen them. Changes/Problems:No major changes since we filed a project change reportin mid-2024. What opportunities for training and professional development has the project provided?The project hired a postdoc, Dr. Burcu Celebioglu, in January 2024. She has now beentrained on numerous methods by PI TravisParker. These include, but are not limited toanalyzing sequencing data using software such as IGVand 'omics databases (NCBI, LegumeInfo, Phytozome, etc.), designing PCR assays for a wide range of targets andpurposes, accessing germplasm from various sources including NPGS, performing RNA extractions and qPCR, fluorescence microscopy, use of geographic software such as QGIS, establishing her own crossing and selection program, and soft skills such as project management, presentation, and networking. In addition, eight interns have been trained by the PI and postdoc in diverse skills such as rearing of plant populations in the field and greenhouse, scientific data management, use of genomics and germplasm databases, screeningpod traits. A comprehensive presentation on both the genetic reversion mechanism for bean pods and the pod shattering mechanism was presented by PI Travis Parker at the International Legume Society meeting in Granada, Spain, and atthe Kirkhouse Trust annual meeting in Arusha, Tanzania.Travis Parker led a full-day training workshop for African breeders at the same meeting in Tanzania. A presentation onthe genetic reversion mechanism for snap bean pods was presented by postdoc Burcu Celebioglu at the UC Davis postdoctoral research symposium.An educational video on field label developmentwascreated by PI Travis Parker and shared on his YouTube channel. How have the results been disseminated to communities of interest?The results have been presented scientifically in the form of articles and presentations. Two articles were published in 2024. These include one peer-reviewed journal article published in Frontiers in Plant Science (IF = 7.3),titled "QTL mapping for pod quality and yield traits in snap bean (Phaseolus vulgaris L.)", in which PI Travis Parker was co-first author. Additionally, a report was published in the Annual Report of the Bean Improvement Cooperative titled "Loci mapped to Pv04 and Pv01 are required for round pod shape in snap bean (Phaseolus vulgaris)." PI Travis Parker again served as co-first author and postdoc Burcu Celebioglu served as middle author on this publication. In addition, results have been disseminated verbally at several internationally recognizedmeetings. They have also been shared privately in writing to private seed companies that have provided material and information in support to the project in the past. What do you plan to do during the next reporting period to accomplish the goals?For Objective 1, the lines who were submitted to Illumina WGS will be aligned with the G19833 and UI111 reference genomes, with features of interest compared and extracted in IGV. Pod traits will be evaluated in summer 2025in the greenhouse. A larger population will be subjected to revertant screening under field conditions in 2025 to better understand whether our two mutations differ in reversion rate. Similarly, the listed stability data from the PVPs will be compared. Long-read sequencing will help in resolving the complex structural features found in snap beans and comparable revertants, including screening for the possibility of varieties with triplications or other extreme genotypes. Candidate genes will be determined from the GWAS analysis results for pod traits from 2018-20, and will be published as a paper. Similarly, all pod traits obtained under UC Davis greenhouse conditions will be analyzed by GWAS and compared with those obtained under previous field conditions. SnAP population SNP information will be combined with those of the MDP and ADP population and structure, phylogenetic tree, and haplotype gene network mapping analyzes will be performed. Towards Objective 2, in the summerthe SnAP+ population will be grown in the greenhouse again and pod traits will be evaluated. Pod anatomy of revertant and non-revertant varieties will be examined with fluorescence microscopy and RT-qPCR will be performed on these pairs, and RNA in situ hybridization will be completed. For Objective 3,the BC1F1 population will be planted, and another backcross will be made to create the BC2F1 population. Then BC2F3 will be determined by testing under field conditions and marker-assisted selection. We are particularly interested in moving the pod fiber/shape allele we believe to be most stable into commercially important but unstable varieties, such as OSU 5630 (see previous) and Hystyle. Findings will be submitted as 2-3peer-reviewed articles at internationally recognized journals. Results will be presented at prestigious meetings, including at the International Plant and Animal Genome Conference (PAG32) in San Diego in January 2025. Shortly after the reporting period (October 2024), arecord of invention was also finalized for the pod shape/fiber gene and genetic screens to study it. This will be critical knowledge and selection resources for breeders working with a nutritious and broadly-consumed vegetable crop.

Impacts
What was accomplished under these goals? Objective 1.Use cutting-edge genotyping and sequencing approaches to understand the genetic basis of environmental and genetic instability in contrasting environments. 1. Generate high-quality genetic data on a panel of approximately 100 snap beans and dry bean controls, which vary in pod traits, using Illumina whole genome sequencing. Extract SNPs from this sequencing to make an expanded SnAP+ panel. Dark-grown leaves of 70 varieties of snap and dry beans with different pod traits were collected and DNA extraction was performed with the Qiagen DNeasy kit. These varieties contain two revertant/non-revertant pairs (five samples in total). After the Nanodrop readings and gel electrophoresis of the extracted DNA was performed, it was submitted to the UC Davis Genome Center for Illumina WGS. Library preparation and QC for these samples is now complete. Sequencing will be conducted at a depth of 15x (11 Gb total per accession). In light of our mapping results (see Activity 1.3), wealso mined Illumina sequencing data we generated in 2023 froma different study. We identified twomutations putatively controlling podfiber/shape, the most important of our studied traits:1) a 50 kb duplication which includesPhvul.004G143500 and no other gene models, and 2) a separate mutation with two 1-2 kbrepeats in the vicinity of the same gene model. Inrevertants, the repetitive structures are completely lost. This repetitive structures could explain reversiondue tounequal crossing over, as described in pod strings (Parker et al. 2022). We are now testing whether these two alleles revert at different rates, since unequal crossing over between long repeats happens at higher frequency than short repeats. To test this, we are developing large quantities of very high purity seed of varieties with these mutations(see below). 2. Phenotype pod traits in the SnAP+ diversity panel and sequenced materials in cool environments (winter greenhouse) and warm environments (summer greenhouses and field trials), to characterize pod traits and identify patterns of genetic reversion and genotype x environment interaction. Phenotyping the SnAP bean population and controls was completed atUC Davis (2024 - winter greenhouse). Three plants were planted for each variety and pod dimensions (length, weight, and height), string, fiber, and thickness evaluations were made on each of threepods. Data collection isnowcomplete. A similar experiment was set up in the greenhouse again for the summer in UC Davis. However, the greenhouse cooling fan had a electrical failure on twodates,with our temperature data loggerrecording maximum greenhouse temperatures of75°C, causing extreme plant stress andmortality. In a separate summer field experiment,clean seed stocks of approximately 100 varietieswere planted at OSU. At the end of August, string, fiber and reversionevaluations were made by postdoc Celebioglu. 4,446 total plants were screened. Reversion was found in sixplants in total, all in a singlevariety(OSU 5630, 7.6% of samples reverting for that variety). Full string formation was observed in fourplants (5.1%), and pod shape reversionwas identified in twoplants (2.5%). Harvested seed will be used for additional large-scale reversion screening in field trials in 2025. We are also mining PVP phenotype data from several hundred SnAP accessions with PVPs, as well as phenotype data generated by postdoc Celebioglu for string and wall fiber in 2018-2020. 3. Genetically map pod traits in the expanded SnAP+ populations through Genome-Wide Association Studies GWAS of string and fiber data collected at OSU between 2018-20 was performed using 60,000 SNPs in BLINK. SNPs were filtered for an MAF of 0.05 with a Bonferroni-corrected significance threshold of 0.01. Candidate gene analysis is ongoing. Similar analyses will be made for Davis winter greenhouse pod measurement data. We have also mined other data sets to map pod traits of interest. This includes accessing unpublished data from Haidar Arkwazee and Jim Myers at OSU and using it identify andmap two loci (on chromosomes Pv04 and Pv01) forpod shape. This work has now been published in the Annual Report of the Bean Improvement Cooperative. Similarly, we worked with Kenyan collaborators Serah Njau and Esther Arunga to use a recombinant inbred population they developed from a dry bean x wild bean cross to map 16 pod quality and productivity traits in snap bean, now published in Frontiers in Plant Science. 4. Use Oxford Nanopore sequencing to generate long-read sequence data to identify structural variation inrevertant / non-revertant pairs for each pod traits. Dark-grown leaves were taken from five isogenic linesdiffering inpod traits. The Promega Wizard HMW DNA extraction kit was used for DNA isolation. QCed DNA is ready to be sent to the UC Davis Genome Center. 5. [Activity 5 has now been merged into an expanded activity 1, see other sections for details] 6. Determine patterns of population structure and understand patterns of historical trait evolution through phylogenetic tree construction, haplotype gene network mapping, and comparison with phenotypic character state changes We used our rapid PCR screen for our Pv04 wall shape/fiber mutations to screen the entire SnAP panel of 378 accessions, based on the expectation that the two mutations vary in reversion rate. Of the accessions, 207 have characterized release dates. Aclear shift in frequency has occured, with a steady, decades-long trend away from the long-repeat mutation that we believe is less stable (at >90% frequency in the 1970s),until in the 2000s (the last decade with data available)it was at<50% frequency among new releases. This selection has historically been done painstakingly by breeders screening thousands oflines for stability. Our new rapid PCR screens make this analysis possible on large populations with same-day turnaround. Objective 2.Characterize the developmental basis of pod quality traits 1. Understand the anatomical basis of pod variation and stability with fluorescence microscopy of revertant / non-revertant and environmentally variable pairs We have begun fluorescence microscopy, using it to identify wall fiber variation corresponding to a mutation in a candidate gene on chromosome Pv05. Additional microscopy will continue in 2025. 2. Understand transcriptional differences which may underlie pod variation using RT-qPCR of candidate genes in revertant / non-revertant pairs We have begun using RT-qPCR, and have used it to identify variations in gene transcription related to the wall fiber variation and a deletionin a chromosome Pv05 candidate gene. Additional RT-qPCR will continue in 2025. We have also inspectedpreviously-generated RNA-seq data, and have found strongevidence supporting our Pv04 candidate gene for the control of pod shape/fiber. We are now workingwith Jack Xu at UC Davis to conduct RNA in situ hybridization for genes of interest affecting pod development and structure. Objective 3.Develop genetic stocks with improved environmental stability and reduced rates of genetic reversion 1. Conduct half-diallel crossing blocks between commercial varieties with contrasting levels pod trait stability We have used 48 accessions as parents in a crossing scheme to improve pod quality and stability. Of these,22characterized to havegood and stable qualityand were used as males, while 26 poor-quality varieties were used as females. From the first crosses, 61 F1s were obtained, whichwere replanted and BC1F1 was obtained with the relevant stable male (total 17) varieties, now ready for planting for the next backcross. We are particularly interested in moving the putatively more stable allele into two commercially important accessions with the unstable allele. 2. Based on phenotyping results in the field and greenhouse, select families to advance to BC2F3? 3. Genotype a plate of 96 BC2F3breeding lines to identify those which have inherited stable alleles from donor parents

Publications

  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Njau SN, Parker TA, Duitama J, Gepts P and Arunga EE (2024) QTL mapping for pod quality and yield traits in snap bean (Phaseolus vulgaris L.). Front. Plant Sci. 15:1422957. doi: 10.3389/fpls.2024.1422957
  • Type: Other Journal Articles Status: Published Year Published: 2024 Citation: Parker, T. A., Arkwazee, H., Celebioglu, B., Gepts, P, and Myers, J. (2024). Loci mapped to Pv04 and Pv01 are required for round pod shape in snap bean (Phaseolus vulgaris). Annual Report of the Bean Improvement Cooperative. 67, 141-142.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2023 Citation: Genetic basis of pod traits related to domestication and consumer preference in common bean. Presentation by Travis Parker at the International Legume Society Conference. Granada, Spain. September 2023.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2024 Citation: The genetic architecture of pod and seed traits in common bean. Invited presentation by Travis Parker at the Kirkhouse Trust Annual Combined Meeting. Arusha Tanzania, June 2024.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2024 Citation: "Understanding and reducing the genetic reversion mechanism for snap bean pods." Presentation by Burcu Celebioglu at the UC Davis Postdoctoral Research Symposium. March 2024.