Theme: Diagnosis of Viability and Germination

Projects
Project profile

A two-dimensional protein gel with marked differentially expressed proteins that characterise viable seeds

Germination tests may or may not always accurately reflect the viability of a seed lot; underestimates being a function of dormancy and / or the length of the germination test. Diagnostic tests of viability and / or germination capacity can thus serve as sustainable alternatives to germination tests. Test development is usually progressed in two steps: characterisation of an approach using a carefully selected model species, followed by validation using a wider range of species. Sometimes, the means of diagnosis in relation to a targeted response (signalling pathway, receptors, etc) is suggested by existing literature in the animal and crop sciences, and often requires a multidisciplinary approach built around molecular biology, biochemistry and biophysics. The objective is to generate an understanding of seeds as integrated systems, and relates strongly to the ‘Systems biology (complexity of life)’ research exemplar identified by the UK Government. Some of the approaches used to diagnose viability / germination involve functional genomics- and proteomics-based innovations, which are restructuring the nature of traditional scientific research; in response to such changes, Kew has noted the need for increased capability and utilisation of genetic technology (1). Nonetheless, more traditional means of assessing seed viability are also being explored, including conductivity and the application of a range of viability stains.

Significant achievements and outputs (2000-2005)

· Established (with the Central Science Laboratory) that release of volatile hydrocarbons is a non-invasive method of seed viability assessment in seeds of two species

· Identified (by microarray with Horticulture Research International and Wageningen University) a handful of candidate genes associated with the transition from dormant to non-dormant state; and used ribosomal proteins as a marker for germination.

· Refined methods for the use of nitrate and gibberellins as dormancy breaking chemicals, and revealed the role of abscisic acid in the germination of one species in both the Rubiaceae and Solanaceae.

· Applied the fluorescein test to > 40 UK and Kenyan orchid species.

· Analysed tetrazolium (TZ) test data for 171 species from 21 families, and demonstrated that tissue preparation has a profound impact on the TZ response in grass seed collections.

· Delivered a major review on the role of embryo culture in viability assessment.

Projects on this theme:

Project Team

Selected CVs

Project Leader: Toorop, Peter

Seed Conservation Department

Lindsay Robb, Ilse Kranner, Rosemary Newton, Hugh Pritchard, Robin Probert, Moctar Sacande, Wolfgang Stuppy, Peter Toorop, (Natasha Ali, Simona Birtić, Chris Wood)