Analysis of Meiotic Barley Mutants

Plant breeding is one of the main ways that genetic knowledge can impact on future sustainable food production.  All such breeding work relies fundamentally on recombination but the control of this process is not fully understood especially in crop plants.  A greater understanding of the control of recombination in crop plants would be particularly useful for crop species such as barley (and wheat) where a highly skewed distribution of meiotic crossover events means that up to half of the genes rarely, if ever, recombine.  In these crops, substantial proportions of the chromosomes are inherited together as a large linkage block, preventing the generation of novel gene combinations and useful variation that could be exploited in breeding programmes. In order to improve our understanding of recombination in barley, we are  characterizing a collection of 14 non-allelic desynaptic (des) mutants that exhibit perturbed meiosis and semi-sterility compared to wild type. A number of these mutants are currently being genetically mapped using the semi-sterility phenotype and cytologically characterized using 3D-SIM. An example is des10  which maps to chromosome 5H and exhibits abnormal synapsis and chromatin structure during prophase I similar to that shown in a ZMM mutant. We recently identified the gene candidate for des10 and we will discuss the implications for its role in synapsis and recombination in barley.