Variation in Light Interception Traits in European Spring Barley Landraces

Improving the efficiency of photosynthesis is a potential strategy for increasing crop yields in the future, but this is only possible if genetic variation exists for this attribute within crop germplasm resources. A key component of photosynthetic efficiency is the plant's ability to intercept light. This study examined the extent of genetic variation, available within barley landraces from Europe, for parameters affecting light interception. Landraces varied in time spent between emergence and full canopy establishment, with those from Northern latitudes reaching canopy closure between 2 and 8 days faster than those from Southern latitudes. There was significant variation in leaf chlorophyll content between the landraces, but this was unrelated to site of origin. Landraces originating from locations with cooler temperature over the growing season held their leaves in a more planophile manner than those from warmer climates, resulting in a negative relationship between leaf angle and mean temperature at site of origin. We conclude that substantial genetic variation in key parameters affecting light interception have evolved among barley landraces in Europe that could be utilised in future breeding programmes to improve the efficiency of photosynthesis and increase crop yields.