Self-incompatibility is a genetic mechanism used by plants to avoid self-fertilisation and promote outcrossing. The mechanism works by enabling plants to recognise their own pollen, and rejecting it in favour of pollen from another plant.
In perennial ryegrass, (Lolium perenne) this mechanism is controlled by at least two genetic regions that have been named S and Z. Knowing the genes at S and Z would help breeders to develop hybrid breeding systems to produce better varieties. However, despite intense research efforts over nearly 70 years, the genes underlying S and Z have remained uncharacterised. This denies grassland farmers the benefits of hybrid vigour which have been demonstrated in many other crops and types of livestock.
A European consortium of researchers from Ireland, UK, Denmark and Switzerland has now uncovered the gene at one of these two main regions conferring self-incompatibility in perennial ryegrass, the major forage grass in Ireland.
Research collaboration over the last 10 years of this consortium used a genetic fine-mapping approach to identify the male component of the S region and provided multiple evidence that an LpSDUF247 gene is involved in its determination.
Dr Susanne Barth, Teagasc research scientist, Crops, Environment and Land Use Programme, Oak Park, Carlow, said: “Knowing the genetic nature of one of the two main determinants will enable us to now work towards more directed hybrids making use of the S and Z self-incompatibility system.
”This strategic research has been supported by Teagasc over the last decade by enabling two postgraduate students under the Teagasc Walsh Fellowship scheme to complete their PhDs on self-incompatibility and characterisation of the S and Z regions in perennial ryegrass.”