SFI research team reveals epigenetic contribution to hybrid vigour in plants
27 October 2015
Hybrid vigour is an elusive property that has contributed to major yield gains in agriculture for crops and livestock. Offspring of some combinations of parents display hybrid vigour when their characteristics (e.g. height, weight, yield) exceed those of their parents. The Science Foundation Ireland (SFI) research team at NUI Galway led by Professor Charles Spillane screened the growth patterns of hundreds of different plant offspring, in collaboration with colleagues in Wageningen University, recently published in plant research journal New Phytologist.
Hybrid vigour is also known as heterosis. Both terms were coined in the early 1900s by George Schull (1914) and Donald Jones (1918). Over the past century, multiple theories have been proposed to explain the genetic basis of heterosis. Most such theories are based on an assumption that offspring displaying heterosis have to be genetic hybrids generated from genetically different parents.
Professor Spillane’s SFI research team in the Plant and AgriBiosciences Research Centre (PABC) at NUI Galway has demonstrated that genetically identical parents can generate genetically identical offspring that display hybrid vigour. This was achieved by generating offspring ‘triploid’ plants that contained three sets of chromosomes by crossing together parents that either had two sets or four sets of chromosomes. Remarkably, the team discovered that a triploid plant that contained two sets of chromosomes from the father and one from the mother displayed a major boost in plant yields.
“Our research opens up exciting new variety combinations possibilities, a potential often overlooked in plant breeding, by simply crossing plants of different ploidies (number of copies of the genome) to potentially increase yield and/or biomass,” said Dr Antoine Fort, the lead lab researcher on the SFI project.
“Our SFI-funded study provides new insights to the understanding of hybrid vigour and opens up new approaches for boosting crop yields through harnessing epigenetic effects that are driven by genome (chromosome) dosage increases. Our next steps are to work with partners in Ireland and internationally to determine whether our approach can be translated to increase yields in the world’s major crops to help meet the rapidly growing planetary demand for crop biomass derived products (food, feed, fibre, fuel and chemicals),” said Professor Spillane.