Emails: Yue Qu (yue.qu@adelaide.edu.au); Scott Boden (scott.boden@adelaide.edu.au)

Cereal grains are pivotal to the global diet, with wheat alone providing 20% of the world’s calorie and protein intake. With an expected global population of 9.8 billion by 2050 and climate change impacting crop productivity, enhancing wheat yield without expanding arable land is crucial. Yield component traits, particularly grain number, offer a sustainable route for yield improvement. Grain number is determined by the number of tillers, spikelets, and florets per plant, and spikelet number and floret primordia survival are key traits for improving yield potential.

Here, we aim to assess and characterize induced and natural genetic variation for spikelet and floret fertility in bread wheat, using germplasm adapted to Australian environments. This work involves identifying and generating variant alleles for genes that modify the survival and fertility of florets and spikelets, including GNI1, HOX2, FT2, FT3, TB1, VRT-2, SVP-1, and DUO1.

Near-isogenic lines (NILs) and CRISPR-Cas9 gene-edited lines are being developed in backgrounds with different photoperiod sensitivity to test the effect of the mentioned gene alleles on floret and spikelet fertility related traits in the greenhouse and field The best alleles in adapted backgrounds will be distributed to Australian breeders.

Gene molecular functional studies are also being conducted through techniques such as RNA-seq and spatial transcriptomics to further elucidate the roles of these genes of interest. Together, this work will offer promising targets for breeders to increase grain production through enhanced floret and spikelet fertility.