An Investigation of Seed Longevity and Antioxidant Changes of Conserved Barley Germplasm

Seed longevity is crucial for the sustainable ex situ conservation of germplasm in genebanks, yet its reliable assessment remains a significant challenge. This research was conducted to predict the longevity of a diverse barley (Hordeum vulgare L.) germplasm collection comprising cultivated and wild types preserved in long-term storage (LTS) at Plant Gene Resources of Canada (PGRC) for 5 to 37 years, and to study the changes in antioxidant levels during storage. In this study, a quadratic random intercept model was applied to viability data to predict longevity as a flexible modelling approach. Seedling lengths, variation in viability and lengths were analyzed in parallel with the viability model as a novel approach to longevity prediction. To account for intra-specific variation, modelling was also performed within several biological subcategories. Additionally, temporal dynamics of antioxidant parameters—total phenolic content (TPC), DPPH radical scavenging assay and total antioxidant capacity by FRAP assay—were evaluated for a subset of covered barley. Barley germplasm remained viable for nearly four decades in the PGRC base collection, suggesting that the first monitoring test could potentially be deferred until at least 35 years after storage. Distinct patterns of viability loss were observed among covered cultivars, hulless barley and covered wild barley, although the latter two groups were underrepresented. Models based on radicle length and on variability in viability (tCVV) and radicle length (tCVRL), aligned with the viability-based curve for all barley. However, for all covered barley and covered breeding lines, radicle length declined faster than viability, suggesting its potential use as an early indicator of viability loss. Together, these alternative modelling approaches reinforce the longevity estimates derived from the viability model. Changes in antioxidant parameters did not consistently reflect the observed patterns of viability loss across three covered barley germplasm types, although antioxidant parameters were highly correlated with each other (r > 0.7; p > 0.001). Interestingly, covered wild barley showed the highest TPC, DPPH and FRAP activities relative to cultivated and breeding barley groups, which increased with prolonged storage—except for notably low values in the intermediate group. Collectively, this study revealed characteristic patterns of viability loss and differences in antioxidant dynamics among barley subgroups under LTS at PGRC, suggesting that defining longevity parameters at the intra-specific levels may improve the management of seed collections in genebanks.

Name thesis:degree_name

Master of Science (M.Sc.)

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Plant Sciences

Grantor

University of Saskatchewan

Year dc:date.issued

2025

Author dc:creator

• Godakanda, Rasanwada Wijesundara

Advisors dc:contributor.advisor

• Bai, Yuguang
• Fu , Yong-Bi

Committee members dc:contributor.committeemember

• Bai, Yuguang
• Tar’an, Bunyamin
• Bueckert, Rosalind
• Qiu, Xiao

• Seed Longevity
• Barley
• Seed Genebank
• Ex-situ Conservation
• PGRC
• Viability
• Longevity Prediction Modelling
• Non-enzymatic Antioxidants
• Phenolic Compounds
• Antioxidant Activity

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10388/17643

OAI identifier oai:identifier

oai:harvest.usask.ca:10388/17643