Barley growing in a field

The Cereal Pathogen Resistance Allele Database (CPRAD) catalogues information on the pathogen resistance alleles reported to be found in genotypes of barley.

The Cereal Pathogen Resistance Allele Database (CPRAD) catalogues information on the pathogen resistance alleles reported to be found in genotypes of barley. It is fully searchable on a range of criteria and initial query results are displayed in a table. From this table you can link to the reference or to a pedigree chart with all that is known about the inheritance of the selected allele. It can also show all that is known about all pathogen resistance alleles in any of the genotypes in the pedigree chart.

On the main query page, selecting each criterion causes a refresh of the remaining criteria so that, for example, selecting pathogen – Rhynchosporium you can only see the Rhynchosporium resistance allele list, only barley, only those genotypes with Rhynchosporium data etc.

In many cases genotypes have not been characterised for their resistance allele. Information about many pedigrees is also unknown, or not in the public domain. Whilst we try to correct as much data as possible, we have created a: ‘Correct or contribute new data’ link leading to a general input page and ‘Add a variety’ or ‘Report incorrect variety’ options and subsequent ‘Add allele details’ forms so that anyone can add further information to the database. Submissions will be moderated through a further administrators interface before inclusion in the database.

The visualization of where alleles may originate from can lead to inferences about intermediate parents leading to enhancement of their value as a germplasm resource.

Examples: check ‘Prisma’ for multiple resistance alleles. Select ‘Chariot’ pedigree with the show all alleles in pedigree to 6 levels options selected. ‘Chariot’ could have Mla6 and Ml(La) through its ‘CSB626/12′ parent and Mla12, Mla7, Ml(Ab) and Ml(Tr3) through its Dera parent. Click the selected genotype hypertext link to display the probabilities that these and other alleles present in the pedigrees are expressed in the genotype. In this way, probabilities that these genes are present in Chariot but are masked by the mlo allele, and therefore implications about its durability, can be assessed. Check also ‘Chalice’ which had ‘Chariot’ as one of its parents, the other parent being ‘Cooper x NFC514/5’, bringing in even more possible alleles.

These analyses highlighted the need for more, and accurate pedigree and resistance allele data.

Current database:

  • total number of host genotypes: 1,500 (nearly all barley)
  • total number resistance alleles: 122
  • total number references: 64
  • pathogen resistance: mostly mildew and some Rhynchosporium.

Development targets originally included wheat and oats host genotypes and resistance alleles for:

  • wheat and oat powdery mildew
  • wheat and barley yellow rust
  • wheat and barley brown rust
  • Rhynchosporium on barley.

The database is built using Microsoft Access interfaced through Active Server Page programming. The work on this database project is funded through Scottish Government and a British Society for Plant Pathology Student Bursary Scheme.

Short-cut link:

UPDATE June 2023

This database resource has not been updated for some years but remains functional.

Currently, all these data are being imported into a much larger and more up-to-date barley database by Paul Shaw in the Hutton Bioinformatics group. Searching and visualisation will be provided by the Helium tool where much more data can be associated and tracked. However, specific resistance allele information is only obtainable from highly focussed studies but it is hoped that these can be incorporated as they are published.