Poster Presentation International Plant Molecular Biology Conference 2024

Deciphering the genetic basis of inflorescence enhancement in wheat (#118)

Guilherme V Yoshikawa 1 , Roshani Badgami 2 , Kate O'Connor 2 , Nicholas Bird 2 , Scott A Boden 1
  1. University of Adelaide, Urrbrae, SOUTH AUSTRALIA, Australia
  2. John Innes Centre, Norwich, Norfolk, United Kingdom

The wheat inflorescence has been maintained as an unbranched spike structure during domestication and breeding, but recent advances in our genetic understanding of flowering indicate that a branched inflorescence could help increase yield. In contrast to the single-grain-producing florets found in wild-type plants, the multi-ovary trait (mov) is characterised by the development of three fertile pistils per floret, all capable of forming grains, alongside a higher frequency of fertile secondary spikelets. We have mapped a dominant mov allele to a 28 Mb region in the 2DL chromosome, encompassing the Pis1 locus previously associated to the trait and over 400 genes. Imaging of developing inflorescences shows mov plants develop faster than wild-type, while mature florets exhibit frequent conversion of anthers to pistils. Preliminary RNA-seq data reveals that genes associated with floral organ identity and paired-spikelet formation are differentially expressed in the mov plants during early developmental stages. The supernumerary organ formation and conversion suggests the presence of a mutation affecting meristem maintenance and organ patterning. We aim to confirm this through a multi-faceted approach involving transcriptomics, mutagenesis, microscopy, and complementation assays. Ultimately, understanding the genetic control of the additional inflorescence organs can lead to the discovery of new alleles and genetic pathways that may improve key yield-related traits and breeding capabilities in wheat.