In cereals, such as wheat and barley, crossing overs (CO) are distributed mainly at the end of chromosomes so that centromeric and pericentromeric regions that include up to 30% of the genes rarely, if ever, recombine. Thus, substantial proportions of the chromosomes are inherited together as large linkage blocks, preventing the generation of novel gene combinations and useful variation that could be exploited in breeding programmes. Therefore, an ability to modify the pattern of recombination in these species would have a profound impact on the breeding of these crops. In order to investigate means of altering the patterns of CO in barley, we have utilised SNP genotyping and cytological procedures, to investigate a collection of non-allelic desynaptic barley mutants. All the desynaptic mutants exhibited perturbed meiosis and semi-sterility compared to wild type with some exhibiting unexpected phenotypes during synapsis (Colas et al, 2016). Overall, studies have suggested a tighter control of meiotic progression of chromatin/meiotic axes compared to the model Arabidopsis.

Although the down-regulation of most meiotic genes leads to abnormal meiosis and loss of recombination, we have found a few variants that increase the number (and sometimes change the distribution) of recombination in barley. This is the case in HvST1 (Orr, Mittmann et al, 2023) HvRECQL4 (Arrieta et al, 2021) and a few TILLING mutants that are currently under investigation. Finally, we have characterised the barley meiosis transcriptome and proteome from cytologically staged anthers (Barakate et a, 2021; Lewandoska et al, 2022), which represent novel resources for cereal studies. The talk will discuss these findings and their potential use for plant breeding and future directions.