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Development of molecular markers for DUS testing in oilseed rape. - VS0117

Newly bred varieties (cultivars) of crops have to undergo statutory testing before being marketed in the UK. Part of this testing is to determine their Distinctness, Uniformity and Stability (DUS). This is currently carried out using tests almost exclusively involving the observation of morphological characters. The main objective of the proposed research programmeare to continue to evaluate the potential of molecular markers (DNA profiling methods) in DUS testing of plant varieties, to study the unifromaty of varieties with respect to selected markers and to develop an operational system for their use. Oilseed rape will be used as a model crop, in a `proof of concept` approach. Sequence tagged site DNA microsatellites (simple sequence repeats, SSRs) will be the profiling method of choice. There are oilseed rape SSRs available to NIAB from previous research projects and more will be made available from IARC-LARS. The use of these will need to be optimised and their relative value for discrimination between varieties demonstrated. This joint project wll onbtain and optimise a number of markers for oilseed rape, test their polymorphism, assess the uniformity of varieties, including hybrids, with regard to SSRs, develop a test set of suitable primers that could be used in DUS testing and then evaluate this test set. This evalaution will be achieved by undertaking a parallel running exercise in which the results obtained from testing as carried out using current systems will be compared with those that would be obtained if the SSR test set were used. the markers will be analysed using automated seperation and detection systems, and the efficient throughput of analysis maximised. One of the stated MAFF PVSD policy objectives is to ensure the evolution of efficient and affordable testing procedures, as well as to increase the science base underpinning statutory testing and contribute towards an improved, efficient and cost-effective DUS testing procedure, but this potential needs to be assessed systematically. the results from this project will contribute toward a coherent assessment of the application of DNA profiling to plant variety testing and hence allow its potential to be evaluated objectively.
The overall objective of this project is to develop a rest set of DNA microsatellite primer pairs for oilseed rape, to evaluate its application in DUS testing and to devise an operational system for its use.

This will be achieved through the following series of objectives:

1. Select a set of at least 40 SSR markers in oilseed rape from both LARS and NIAB.
2. Examine the polymorphism of 10 current varieties using these SSRs.
3. Design and synthesise at least 15 fluorescently tagged SSR primer pairs.
4. Design and produce multiplex primers sets.
5. Assess the uniformity of 48 individuals from 10 current varieties, using the SSR multiplexes.
6. Evaluate multiplexed primer sets for polymorphism, uniformity, map position.
7. Screen a wider variety collection of at least 30 varieties, including hybrids, using the most useful SSRs (the test set).
8. Generate databases of variety profiles.
9. Compare data from use of ABI 377 and LiCor systems.
10. Re-assess test set of SSR primer pairs.
11. Analyse 30 of the current National List varieties for uniformity (48 individuals), using this test set.
12. Examine 10 selected candidate varieties, including hybrids, of oilseed rape (D and U) with this test set.
13. Carry out a more complete 'parallel running' exercise (D and U) with this test set.
14. Examine at least 4 different seed lots of 5 selected varieties of oilseed rape (D and U) with this test set.
15. Devise a SSR-based testing system optimised for maximum throughput and efficiency.
Project Documents
• Final Report : Molecular Markers for DUS Testing of Oilseed Rape   (1600k)
Time-Scale and Cost
From: 1999

To: 2001

Cost: £240,280
Contractor / Funded Organisations
Rothamsted Research (BBSRC)
Plant Varieties and Seeds              
Plants and Animals              
Variety Testing              
Fields of Study
Plant Varieties and Seeds