About

Barley is a major crop worldwide, with Europe producing the greatest share (~60 MT/year). Beside grains, barley plants produce an almost equivalent amount of straw, considered in the past as a secondary product of minimal value. A change in the biomass partitioning from straw to grains contributed highly to the genetic progress to increase yield. The current plant architecture results from the necessity of increasing the harvest index.

The increasing demand for renewable materials makes straw, and especially barley straw - characterised by the largest content of carbohydrates among cereals- a valuable product for its potential conversion into biofuels and other products. Indeed, barley crop residues are desirable feedstock because of their low cost, immediate availability, no competition with food, and relatively concentrated location in the major grain growing regions.

The BarPLUS objective is to revise the current barley plant architecture and photosynthesis performance to maximise the farmer’s income (grain plus straw value). Therefore it would identify the genes, alleles and lines needed to increase bar­ley plant biomass, without penalty on grain yield, in the agro-climatic and management scenarios predicted for 2030 in Southern (Spain and Italy) and Central (Germany and Poland) Europe.

Results

BarPLUS has aimed to identify lines, genome regions, genes and alleles conferring increased barley biomass without penalty in grain yield, for the agro-climatic scenarios predicted for 2030 in central and south European environments. The genetic basis and the genetic variability of canopy architecture and of photosynthesis efficiency were investigated in the barley mutant population HorTILLUS and within the WHEALBI germplasm collection that represent worldwide barley natural genetic diversity.

Outputs include a list of 41 missense allelic variants in five candidate genes involved in biomass production. Moreover, the forward genetics analysis led to the selection of 10 lines, with either broad leaves, improved photosynthesis, increased number of tillers, or improved leaf angle.

A combination of exome capture, illumina-based sequencing and bulked segregant analysis allowed to identify the candidate mutated genes in two of the ten selected lines. In addition, part of the selected genetic material has been included in a total of 10 field trials performed between 2016 and 2019 in Italy, Spain and Poland. The crop modelling analysis highlights that straw biomass increase can range between 15 and 30%, whereas yield improvement can vary between 10 and 30% by keeping management practices equal to those currently adopted by farmers.