Barley and spelt differ in leaf silicon content and other leaf traits

Abstract

Silicon is considered to be a beneficial element for plants, improving their potential to overcome various stress conditions. Accumulation of silicon differs across different plant species and during plant development, leading to differences in their sensitivity to environmental constraints. We studied the leaf contents of silicon and some other elements for barley (Hordeum vulgare L.) and spelt (Triticum spelta L.) in their vegetative and reproductive stages, while also monitoring the different morphological, biochemical, and optical leaf traits. For barley, the leaf silicon and calcium contents were 1.6% and 1.1%, respectively, and for spelt, they were 1.4% and 0.6%, respectively. There were considerable morphological differences between these two species, including significantly higher prickle hair density in barley, which was positively related to leaf contents of phytoliths, silicon, and calcium. The reflectance of the barley leaves was significantly (p ≤ 0.05) positively related to leaf phytolith and silicon contents throughout the whole spectrum, while light transmittance was significantly (p ≤ 0.05) negatively related to leaf phytolith and silicon contents in the visible and near infrared regions. For spelt, there were no such correlations. Barley showed a significant increase in total and phytolith-bound silicon in the leaves from the vegetative to reproductive stage, which was not the case in spelt. Differences between barley and spelt were also observed in stomata density and length, which would also affect water management in these plants, and thus also their uptake of silicon and calcium.