Identity matters: understanding spike architecture to increase grain number in wheat (UAUY_J26DTP)

Wheat provides 20% of the calories and protein consumed by humans. The world population will reach 9 billion by 2050, which requires food production to more than double. Although plant breeding has led to the development of high-yielding wheat varieties, it also created a bottleneck effect, reducing genetic variability and thus limiting the potential for further improvements and adaptations. One way to increase genetic variability is to explore untapped genetic resources such as landraces, wild relatives, and closely related species.

Einkorn (Triticum monococcum), the first domesticated wheat species, is a close relative of modern wheat. Its inflorescence consists of spikelets, each of which forms a single flower (floret) and is encased by tough bracts (glumes). The floret consists of the leaf-like lemma and palea, which enclose the reproductive organs. The glumes of Einkorn are tenacious, meaning that the grain does not readily separate from them. There exists, however, a naturally occurring mutant of Einkorn that has been described as free-threshing, where the grain separates freely from the chaff.

We have recently identified a strong candidate for the gene underlying this trait. Our initial phenotypic analysis suggests that the organ identity of glumes is changed to that of lemmas, suggesting that the mutant transforms glumes into sterile flowers. We hypothesise that this could be exploited to increase grain number per spikelet, by combining several mutations to fully transform glumes into fertile flowers.

This project provides a clear goal to characterize an exciting mutant in a wheat relative, while also allowing plenty of room for the student to take ownership of the project and expand into their areas of interest and according to the results. The student will receive mentoring and outstanding training in modern crop genetics, genomics, data analysis, and bioinformatics.