Investigation of Genetic and Environmental-Associated Variation of Flavor-Related Attributes in Bioparental and Natural Cucumber Populations and Their Correlation with Human Sensory

Fresh cucumber sensory quality is composed of texture, taste (non-volatiles), and aroma (volatiles), yet little is known about genetic variation in natural populations and influence of internal and external factors on these traits. This study hypothesized that significant differences would be observed within a genome wide association study (GWAS) panel and between environments. This study aimed to investigate the role of genetics and environments on sensory traits using a GWAS panel consisting of 210 (2 reps, 420 total) cucumber lines grown under greenhouse (GH) and open-field (OF) conditions. The tasks completed included: 1) investigating variation in texture-related parameters as it relates to longitude, tissue, and maturity; 2) measuring overall hardness; 3) quantifying taste-related compounds including sugars, acids, and minerals; 4) profiling volatiles including C6 and C9 aldehydes and alcohols; and 5) conducting descriptive sensory analysis to link instrumental analysis with human perception. Results showed: 1) Overall hardness of cucumbers increased with maturity, with 28 day fruits 3.5 times higher than 7 day fruits. Tissue-specific hardness increased outward, with exocarp 6.7 times higher than center tissues; 2) GH cucumbers had significantly lower overall hardness (21.76 ± 1.29 N) than OF cucumbers (28.69 ± 1.45 N). 3) GH samples had significantly lower concentrations of glucose (19.15 vs. 29.43 mg/mL) and sucrose (0.44 vs. 1.54 mg/mL), but significantly higher concentrations of fructose (21.75 vs. 20.03 mg/mL). Malic acid (2.37 vs. 2.07 mg/mL) and citric acid (1.08 vs. 0.99 mg/mL) were significantly higher in GH than OF samples. GH samples exhibited significantly lower concentrations of silicon (180.60 vs. 269.95 mg/100g), potassium (236.09 vs. 379.02 mg/100g), and phosphorus (83.46 vs. 282.69 mg/100g). 4) C6 and C9 aldehydes were dominant volatiles, with (E)-2-nonenal accounting for 19.55% of the total C6 and C9 aldehydes and alcohols, hexenal 22.01%, and (E,Z)-2,6-nonadienal 9.43%. 5) Sensory correlation analysis revealed strong relationships between crispy texture and instrumental overall hardness (r = 0.78), and between (E,Z)-2,6-nonadienal and melon-like aroma (r = 0.79). Overall, this study integrated GWAS with physical and physiochemical profiling to link genetic variation and environment to cucumber sensory traits, providing a foundation for breeding programs to improve sensory quality.

Name thesis:degree_name

Doctor of Philosophy

Discipline thesis:degree_discipline

Nutrition

Grantor

Texas Woman's University

Year dc:date.issued

2025

Author dc:creator

• Duan, Cassidy

Advisor dc:contributor.advisor

• Du, Xiaofen

Committee members dc:contributor.committeemember

• Warren, Cynthia
• Beatty, John
• Wang, Danhui
• Weng, Yiqun

• Cucumber
• Agriculture
• Texture
• Volatiles
• Flavor
• Sensory
• Genome wide association study

Language dc:language.iso

English

Handle dc:identifier.uri

https://hdl.handle.net/11274/17439

OAI identifier oai:identifier

oai:twu-ir.tdl.org:11274/17439