Advancing production of malting hybrid barley via conditional male sterility (Hy-Barley)

Project Description for Find-A-PhD Advert (max 400 words).

Control of pollen production is fundamental to develop hybrid seed programmes. Hybrid varieties are commercialised in the UK. These hybrids are six-row winter type lines for the livestock feed market, and thus are not aligned with the UK farmer preferences for two-row spring barley for malting.

My lab proposes to follow a forward genetic approach to discover new genetic mechanisms that induce environmental sensitive genic male sterility (EGMS) when perturbed. The major deliverable would be developing genetic materials for hybrid seed production in two-row spring malting barley.

Forward genetic and map-based gene cloning uncovered multiple genes and molecular mechanisms controlling male sterility in rice, maize, and wheat. The James Hutton Institute holds a collection of ~100 male sterility barley mutants backcrossed to cultivar Bowman to generate a collection of Near Isogenic Lines (NILs). Among these, there are about 70 male-sterile lines that have been backcrossed for at least four generations.

Other than reporting their recessive nature, these NILs remain mischaracterised. We don't know: (i) the loci or genes controlling the male sterility phenotype, (ii) what triggers male sterility, or (iii) if environmental signals can restore the male fertility. My lab has started evaluating this population and validated the male sterility phenotype of all 70 NIL populations.

These lines provide valuable resources to identify novel genes regulating male sterility, some of which are regulated by environmental conditions based on preliminary observations. The PhD project will characterise a subset of the Bowman male sterile NILs to identify novel genes regulating male sterility and develop genetic resources. The three objectives are: (i) to select a subset of 15 NILs and identify NILs exhibiting an EGMS phenotype, (ii) to identify when developmental defects occur in anther and to characterise what is cellular and subcellular anomalies among NILs exhibiting an EGMS phenotype, and (iii) to identify the genomic region associated with male sterility performing genetic mapping for gene cloning.

This project will support the development of knowledge and skills of the PhD candidate on phenotyping, cutting-edge microscopy techniques and various kind molecular work.

The preliminary data suggest all aims are achievable. Success in developing hybrid seed production could increase barley by at least 15%, representing an extra 1.0 and 13.4 million metric tons of barley, in the UK and in Europe, grown with the same inputs and footprint. Moreover, hybrids are known to increase crop resilience to stresses.

Therefore, developing hybrids is both relevant and impactful to support the production of low input and climate resilient barley in Scotland, the UK, and globally.