Monitoring viability of seeds in gene banks: developing software tools to increase efficiency

Authors: Pohl, Josef; Greene, Stephanie; Walters, Christina

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/22/2015
Publication Date: 7/5/2015
Citation: Pohl, J.M., Greene, S.L., Walters, C.T. 2015. Monitoring viability of seeds in gene banks: developing software tools to increase efficiency. Meeting Abstract. nternational Seed Science Society, Seed Longevity Workshop, Wernigerode, Germany, July 5-8, 2015. pp 73.

Interpretive Summary: Monitoring the decline of seed viability is essential for effective long term seed storage in ex situ collections. Recent FAO Genebank Standards recommend monitoring intervals at one-third the time predicted for viability to fall to 85% of initial viability. Species longevity in storage can be estimated using two approaches: i) The Viability Equations (Ellis and Roberts, 1980) using NCGRP conditions of RH and temperature and species constants found in the Kew Seed Information Database, and ii) NCGRP longevity results obtained at 5oC, fitted to Avrami kinetics and adjusted to -18oC storage (Walters et al., 2005). We present two software tools that leverage these models to assist making decisions about what accessions are in need of monitor tests. Our approach was to calculate time to 85% initial viability using both methods. The first tool generates a list of genebank accessions from the collection that are in need of monitoring based on a monitoring interval set at 1/3 of the total time needed for germination to decline to 85% viability, which is estimated using both models for a given taxon and initial germination. The second tool is a visualization product which displays viability data against curves generated by the model. These tools increase genebank efficiency, since resources can be saved once an optimal interval is identified based on species-specific aging kinetics.

Technical Abstract: Monitoring the decline of seed viability is essential for effective long term seed storage in ex situ collections. Recent FAO Genebank Standards recommend monitoring intervals at one-third the time predicted for viability to fall to 85% of initial viability. This poster outlines the development of software tools to identify accession-specific monitoring intervals. The tools were developed for the long term base collection of the USDA National Plant Germplasm System, located at NCGRP. We felt that monitoring intervals should be based on seed longevity estimates characteristic for each species in the collection. Species longevity in storage can be estimated using two approaches: i) The Viability Equations (Ellis and Roberts, 1980) using NCGRP conditions of RH and temperature and species constants found in the Kew Seed Information Database, and ii) NCGRP longevity results obtained at 5oC, fitted to Avrami kinetics and adjusted to -18oC storage (Walters et al., 2005). We present two software tools that leverage these models to assist making decisions about what accessions are in need of monitor tests. Our approach was to calculate time to 85% initial viability using both methods. The first tool generates a list of genebank accessions from the collection that are in need of monitoring based on a monitoring interval set at 1/3 of the total time needed for germination to decline to 85% viability, which is estimated using both models for a given taxon and initial germination. The second tool is a visualization product which displays viability data against curves generated by the model. The tools can be parameterized based on time, taxonomy, institutional genebank standards and estimated deterioration time courses when needed and are compatible with GRIN-Global. These tools increase genebank efficiency, since resources can be saved once an optimal interval is identified based on species-specific aging kinetics.