Effects of light intensity on yield components, carbohydrate economy and cell-wall constituents in spring barley (Hordeum distichum L.).

Abstract

The effects of light intensity (129, 86 and 37 W/msuperscript 2) after spikelet initiation on development, yield and chemical composition were studied in spring barley cv. Trumpf under controlled conditions. Reducing the light intensity resulted in fewer shoots/plant, prolonged the leaf area duration, lowered the specific leaf wt and delayed shoot and ear development. The light intensity strongly influenced the number of aborted spikelets, the number of grains/ear and 1000-grain wt. During leaf, stem and ear development the content and amount of water-soluble carbohydrates (WSC) in leaves plus stems decreased. At the same time there was a strong increase in content and amount of cell-wall constituents (CWC), especially in leaves and stems. This implies that the formation of CWC requires a large consumption of WSC. Reducing the light intensity diminished the production of WSC and CWC appreciably. The percentage of WSC in stems at anthesis correlated well (r = 0.68) with the number of grains/ear at final harvest, calculated over main shoot, 1st and 2nd tillers. The high amount of WSC in the stems of the plants at the 2 highest light intensities at maturity implies an insufficient storage capacity in the grains. (Abstract retrieved from CAB Abstracts by CABI’s permission)