Source: TEXAS A&M UNIVERSITY submitted to NRP
TOMATO FRUIT FIRMNESS: BREEDING FOR LONG SHELF LIFE WHILE CONSERVING QUALITY IS NOW POSSIBLE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1030054
Grant No.
2023-67013-39616
Cumulative Award Amt.
$649,723.00
Proposal No.
2022-10299
Multistate No.
(N/A)
Project Start Date
Sep 1, 2023
Project End Date
Aug 31, 2027
Grant Year
2023
Program Code
[A1141]- Plant Health and Production and Plant Products: Plant Breeding for Agricultural Production
Recipient Organization
TEXAS A&M UNIVERSITY
750 AGRONOMY RD STE 2701
COLLEGE STATION,TX 77843-0001
Performing Department
(N/A)
Non Technical Summary
Development of flavorful and nutritious yet firm and long shelf-life tomatoes is the holy grail in tomato improvement. So far, tomato genes carrying mutations blocking ethylene synthesis have been successfully used to modulate fruit firmness and to extend shelf-life in commercially available tomatoes. Unfortunately, besides the beneficial effect on delaying softening, these genes negatively affect fruit color, flavor, and nutritional value. As a result, it is generally accepted that most modern tomato cultivars have lost their flavor and nutritional content affecting consumption and supermarket sales. As opposed to commercial tomato cultivars, the Texas A&M TAM-SP18-157 inbred line is extraordinarily firm resulting in long shelf-life fruit that conserves quality since ethylene ripening process is not blocked. Tomatoes from the inbred line are characterized by their high dry matter and lack of locule gel. These characteristics make tomatoes from TAM-SP18-157 exceptional for fresh consumption since they are firm and do not leak when sliced or diced, a highly desirable characteristics by the industry and consumers. When used as a parental line, the resulting F1 hybrids show enhanced fruit firmness, sugar & acid content, dry matter, and yield. As part of the Plant Breeding for Agricultural Production "improved taste, aroma, or nutrition" priority area, this proposed project aims to characterize and map the exceptional tomato traits controlling locule gel and pericarp firmness in TAM-SP18-157 for their utilization in cultivar development. Long-term goal is to promote local production of high-quality tomatoes to keep US industry competitive, increase consumption, and reduce the dependency on imports.
Animal Health Component
60%
Research Effort Categories
Basic
30%
Applied
60%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2011460108180%
7011460100010%
2011460108010%
Knowledge Area
201 - Plant Genome, Genetics, and Genetic Mechanisms; 701 - Nutrient Composition of Food;

Subject Of Investigation
1460 - Tomato;

Field Of Science
1081 - Breeding; 1000 - Biochemistry and biophysics; 1080 - Genetics;
Goals / Objectives
Development of flavorful and nutritious yet firm and long shelf-life tomatoes is the holy grail in tomato improvement. So far,tomato genes carrying mutations blocking ethylene synthesis have been successfully used to modulate fruit firmness and to extend shelf-life in commercially available tomatoes. Unfortunately, besides the beneficial effect on delaying softening, these genes negatively affect fruit color, flavor, and nutritional value. As a result,it is generally accepted that most modern tomato cultivars have lost their flavor and nutritional content affecting consumption and supermarket sales. As opposed to commercial tomato cultivars, the Texas A&M TAM-SP18-157 inbred line is extraordinarily firm resulting in long shelf-life fruit conserving quality. Tomatoes from the inbred line have high dry matter and lack of locule gel. These characteristics make tomatoes from TAM-SP18-157 exceptional for fresh consumption since they are firm and do not leak when sliced or diced, a highly desirable characteristics by the industry and consumers.This proposed project aims to characterize the novel tomato firmness traits in TAM-SP18-157 breeding line to develop tomato cultivars with extended shelf life while conserving quality using molecular breeding and metabolomic approaches.This project will target threeindependentsub-objectives:(1)Identify gene controlling lack of locule gel phenotype and fine mapping pericarp firmness QTLs.Hypothesis:fruit firmness traitsare the result of a lack of locule geland pericarp QTL firmness novel alleles inTAM-Sp18-157.(2)Determine the effect of locule gel and fruit pericarp firmness on nutritional content in tomato.Hypothesis:dry matter in TAM-Sp18-157 results in improved nutritional content that can be maintained during produce shelf-life.(3)Determine the effect of locule gel and pericarp fruit firmness traits on tomato ripening and shelf-life.Hypothesis:firmness traits in TAM-Sp18-157 modify the ripening process resulting in extended shelf-life.
Project Methods
OBJECTIVE (1). Identify gene controlling lack of locule gel phenotype and fine mapping pericarp firmness QTLsFor fine mapping QTL regions and identification of the mutation responsible for the lack of locule gel in TAM-SP18-157, we will use DNA bulked segregant analysis and whole-genome resequencing in an F2 mapping population to identify putative genes. Identified putative genes and QTL markers will be validated for their implementation in molecular breeding programs.OBJECTIVE (2). Determine the effect of locule gel and fruit pericarp firmness on nutritional content in tomatoFirmness traits in TAM-SP18-157 resulting in lack of locule gel and higher dry matter content are expected to alter phytochemical composition in tomato fruit in both homozygous and heterozygous states. Therefore, evaluating nutritional composition at harvesting and its effect on post-harvest shelf life is necessary. The initial phytochemical profile will be performed on fully ripe tomatoes (Breaker +15); once key differential compounds are identified, targeted compound content during storage will be conducted for post-harvest shelf-life characterization.OBJECTIVE (3). Determine the effect of locule gel and pericarp fruit firmness trait on tomato ripening and shelf-lifePreliminary results indicate that tomato fruits from homozygous high firmness TAM-Sp18-157 genotype complete their ripening process, indicating that ethylene synthesis is not disrupted. However, a previous study reported that the onset of ethylene production occurs in the locule tissue of green tomato fruit before its initiation in the pericarp, and locule cell develops greater sensitivity to ethylene at an earlier stage than pericarp cells (Brecht, 1987). Therefore, it is possible that extended shelf life in TAM-Sp18-157 lacking locule gel can be explained by delayed or reduced ethylene production in the fruit. The effect of the heterozygous trait and pericarp firmness will also be evaluated.

Progress 09/01/23 to 08/31/24

Outputs
Target Audience: Our team is committed to delivering improved tomato breeding lines to stakeholders, releasing cultivars with greater quality and long post-harvest shelf-life (medium- to long-term goal), and providing consumers with a flavorful and highly nutritious supply of this healthy vegetable. The data, results, tools, and resources obtained and developed from this project are being made public throughreports, presentations, and AgriLife news website. In addition, results were disseminated as evidence-based research to undergraduate and graduate students as guest lectures and seminars by Dr. Avila on breeding for flavor, nutritional content, and quality in horticultural crops, part of the Texas A&M Department of Horticultural Sciences courses and Zamorano University, Honduras. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?-PostDoc is being trained on trait mapping -Research scientist and graduate student were trained on tomato quality data acquisition and analysis using HPLC -A group of fourundergraduate students participated in summer internship in Dr. Avilar research lab receiving training in quality measurement in tomato. How have the results been disseminated to communities of interest?-PI, Dr Avila organized a workshopat theAmerican Society for Horticultural Sciences Annual Meeting, Hawaii in Sept 2024 to discuss current trends in breeding for Post-harvest shelf-life in vegetables. The workshop will include five international and national panelist that will present their current work and strategies. -Current results were disseminatedto the scientific communityat the American Society for Horticultural Sciences and Society?for Experimental botanyAnnual Meetings Jana Jeevan Rameneni, Devi Kandel, Ada N. Munoz, Anaizar R. Garza, Kevin Crosby, C.A. Avila. 2023. Effect of fruit locule gel on post-harvest shelf-life and quality in tomato.Annual Meeting of the American Society for Horticultural Sciences. Avila, CA, JJ Rameneni, D. Kandel. 2024. Lack of Locule gel increases post-harvest shelf-life and quality in tomato. Annual Meeting of the Society for Experimental Biology. Prague, Czech Republic, -Data was presented to Texas A&M AgriLife Extension District 12 extension agents for dissemination with local producers. What do you plan to do during the next reporting period to accomplish the goals?Objective 1 -We are repeating linkage mapping analysis to identify putative candidate genes involved in locule gel development in TAM-SP19-157 using three models (simple and composite interval mapping, and multiple interval mapping using two LOD thresholds) to narrow down locule gel locus candidates and additional firmness QTLs.Candidate genes will be evaluated for gene expression and sequenced for mutation identification. Candidate genes will be overexpressed or knocked out for functional reverse genetic. Alternatively, developed mapping populations will be phenotyped and genotyped for fine mapping as needed. -Generation mean analysis will be performedto estimate the relative importance of average effects of the genes (additive effects), dominance deviations and effects due to nonallelic genetic interactions in fruit firmness trait inTAM-SP19-157 Objective 2 -Collected tomato samples in soft parental lineTAM-SP18-501, firm lineTAM-SP18-157, and F1 crosscrosswill be analyzed by HPLC and GC-MS for nutritional composition and volatile analysis. -Pericarp tissue samples will be collected insoft parental lineTAM-SP18-501, firm lineTAM-SP18-157, and F1 cross to determine the effect of locule gel on pericarp composition and locule independentfirmness observed in heterozygousplants. -Tissue from additional soft parental lines and F1 hybrids will be collected for chemical composition analysis to evaluate genetic background effect. Objective 3 -Total texture profile analysis will be measured insoft parental lineTAM-SP18-501, firm lineTAM-SP18-157, and F1 cross. Variables to measure include hardness, cohesiveness, elasticity, brittleness, chewiness, and gumminess. -Locule gel viscositywill be measured insoft parental lineTAM-SP18-501, firm lineTAM-SP18-157, and F1 hybrid in pericarp and inner tissuesto determine locule gel contribution to firmness. Additional parental lines will be evaluated to determine genetic background effects.

Impacts
What was accomplished under these goals? Objective 1 -F1 cross (TAM-SP18-501 xTAM-SP18-157) was backcrossed to bothparental lines, the soft line TAM-SP18-501 andfirm lineTAM-SP18-157 to develop BC1P1 and BC1P2 populations. The BC1 populations were phenotyped forsegregation of locule gel trait. Results corroborate that a single recessive gene is responsible of controlling locule gel absence in TAM-SP18-157 -Two F2 populationsand four BC for both parentals were developedfor fine mapping locule gel and QTLs Objective 2 -Tissue was collected fromTAM-SP18-501, firm lineTAM-SP18-157, and F1 cross for nutritional content and gene expression analysis at different tomato ripening stages (Mature green, Breaker +3, +9, and +12 days). -HPLC Protocols for Ascorbic acid, carotenoids, and amino acids were optimizedfor tomato phenotyping. Samples are currently being analyzed by HPLC and GC-MS Objective 3 -Firmness, water lossand quality parameters were evaluated in soft parental lineTAM-SP18-501, firm lineTAM-SP18-157, and F1 cross. Tomato samples were collected at mature green, breaker +3day, breaker +9days, breaker+15 days. Firmness and quality parameters were measured at harvest, 7-DAH and 14-DAH.Lack of locule gel (gg)increasesfruit firmnessdelating fruit softening pre- and post-harvesting resulting in tomatoes withhigher brix and low acidity. Lower water loss was observed in tomatoes lacking locule gel.In addition to locule gel trait, other factors in TAM-SP18-157 increase firmness in heterozygous (Gg) F1 fruits, having intermediate values between parental lines. Data indicatesthat tomatoes lacking locule gel (gg) or heterozygous for the trait (Gg) can be harvested at later ripening stages allowing in vine ripening while keep firmness and postharvest shelf life. -Ethylene emission mas determineinsoft parental lineTAM-SP18-501, firm lineTAM-SP18-157, and F1 cross at different ripening stages. Contrarily to our hypothesis, emission of ethylene in long-shelf life firm line TAM-SP18-157 lacking locule gel is significantly higher to wild-type tomatoes at all time points measuredafter initiating ripening (Breaker +3, +9, and+15 days)indicatingthat long-shelf-life inTAM-SP18-157 is not due to disruption of ethylene synthesis process. -Gene expression of fruit ripening/ethylene responsemarker genes PL, LOB1, and RIN were measured insoft parental lineTAM-SP18-501 andfirm lineTAM-SP18-157. No difference in gene expression was observed at breaker+3 days nor breaker+9 days indicating no disruption of ethylene synthesis in agreement with ethylene emission results. -Fruit locule and pericarp tissue viscosity was measured in soft parental line TAM-SP18-501 and F1 hybrid(TAM-SP18-501 xTAM-SP18-157). No differences were observed in locule tissue viscosity. However, pericarp viscosity was higher almost double in F1 hybrid as compared with soft parental line, indicating that observed increased firmness in F1 tomatoesis due to factors in the pericarp not in the locule inner tissue.

Publications

  • Type: Websites Status: Published Year Published: 2023 Citation: 2023. Schattenber, P. In search of the holy grail of tomatoes Texas A&M AgriLife researchers target tomato firmness, shelf life, nutritional value. July 5th 2023. https://agrilifetoday.tamu.edu/2023/07/05/in-search-of-the- holy-grail-of-tomatoes/
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Jana Jeevan Rameneni, Devi Kandel, Ada N. Mu�oz, Anaizar R. Garza, Kevin Crosby, C.A. Avila. 2023. Effect of fruit locule gel on post-harvest shelf-life and quality in tomato. Annual Meeting of the American Society for Horticultural Sciences.
  • Type: Other Status: Published Year Published: 2023 Citation: Avila, C.A. 2023. Tomato Fruit Firmness: Breeding for Long Shelf Life while conserving quality is now possible. Texas A&M Horticulture Department Fall Seminar. November 16th, 2023
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Avila, CA, JJ Rameneni, and D. Kandel. 2024. Lack of local gel increases post-harvest shelf-life and quality in Tomato. Annual Meeting of the Society of Experimental Biology. Prague, Czech Republic. July 2-5th
  • Type: Conference Papers and Presentations Status: Submitted Year Published: 2024 Citation: Avila, CA, JJ Rameneni, A. Aduragbemi, K. Kandel. 2024. High dry matter in tomato pericarp and locule increases post-harvest shelf-life and quality in tomato. Annual Meeting of the National Association of Plant Breeders. Saint Louis, MO July 2024