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Physiological, biochemical and molecular characterisation of bud dormancy in woody perennial species - HH2203NSF

The development of endodormancy is an important adaptive strategy in woody perennial plants and greatly influences their use in horticulture, in both the food and landscape sectors. Many morphological and physiological changes are associated with endodormancy in woody perennials, including those responsible for related traits (e.g. timing of spring bud flush, timing of autumn bud set, degree of acclimation and chilling requirements). Modern horticultural developments have led to an urgent need for a better understanding of bud dormancy in woody perennials. However, due to our lack of understanding of the basic mechanisms involved in this developmental process, current practices aimed at controlling or manipulating dormancy rely entirely on empirical approaches.

The aim of this project is the identification of physiological, biochemical and molecular parameters involved in the control of endodormancy in woody perennials. Our approach is based on novel methodologies for the study of bud dormancy developed over the past few years at SCRI through research funded by the EU-Framework IV (BIO4-CT96-0529) and subsequently by SERAD (RO 550). The research focused on the potato tuber as a model system and has resulted in the identification of key physiological and biochemical events associated with the dormancy process in tuber buds. A major outcome of this approach was the identification of biochemical markers precisely defining the bud dormancy status. These markers have been used to successfully isolate genes specifically associated with the release from endodormancy in tuber buds, prior to any visible sign of bud growth. We propose to adopt a similar methodological approach for the study of bud dormancy mechanisms in woody perennials. We intend to use Rubus idaeus as a model system for the elucidation of physiological, biochemical and molecular mechanisms controlling endodormancy. In addition, we aim to identify biochemical markers for bud dormancy in Rubus, and use Syringa vulgaris to test their widespread occurrence in woody perennials. A further objective of the project is the development of a better mechanistic understanding of bud dormancy in woody perennials. This will not only improve current horticultural practice, but also will facilitate novel production systems and provide opportunities to breed improved horticultural crops for the future.

It is appropriate for MAFF to support this work under the new AU on functional genomics and plant development. The current project represents a natural progression of HH 1519 “Year round soft fruit production with particular regard to raspberry and blackberry” carried out at SCRI. The identification of key determinants of bud dormancy in raspberry canes was highlighted in the final program report as the most important objective for future research in the area (MAFF Review of Horticulture and Potatoes Policy Division’s R&D Programme, December 2000).

1. Develop experimental conditions for the study of endodormancy and paradormancy in raspberry buds.

2. Characterise metabolic processes in the buds and subtending tissues that are relevant to the bud dormancy status.

3. Examine the role of phloem transport and water relations during the dormancy phase transitions (endo- and para-dormancy).

4. Identify changes at the biochemical and molecular levels that are associated with the dormancy status of Rubus buds.

5. Characterise bud dormancy in Syringa vulgaris and carry out comparative biochemical analyses with raspberry buds.

6. Identify and validate biochemical markers of bud dormancy status in Rubus and Syringa and develop appropriate diagnostic tools.

7. Develop a mechanistic hypothesis of bud dormancy requirements in woody perennials for exploitation in the development of predictive models for chilling requirement and growth optimisation.

Project Documents
• Final Report : Physiological, biochemical and molecular characterisation of bud dormancy in woody perennial   (6681k)
Time-Scale and Cost
From: 2001

To: 2005

Cost: £365,201
Contractor / Funded Organisations
Scottish Crop Research Institute
Organic Farming              
Sustainable Farming and Food              
Fields of Study