Spectral Light Measurements Within Canopy of Narrow- and Wide - Leaf Barley Plants

Light quantity and quality within canopy of a narrow-leaf mutant and wide-leaf plants of spring barley (cv. Damazy) were compared. The mutant induced in the result of Co-60 gamma irradiation displayed horizontally oriented leaves of reduced blade width by about 50 per cent and the blade length decreased by about 30 per cent, in comparison to the original form. The narrow-leaf trait was found to be controlled by a single recessive gene. Photosynthetically active radiation (PAR) was enhanced by about 50 per cent at the level of the third upper leaf and by about 150 per cent at the stem base in the canopy of the mutant, in comparison to the wild-type plants. Spectroradiometric measurements showed also the effect of the leaf size on the light quality. The red (600–700 nm) far-red (700–800 nm) ratio was higher in the mutant canopy in comparison to the wild-type plants, mostly due to increased contribution of the red wavelengths. Possible benefit effect of reduced leaf size on plant morphogenesis is discussed.