Impact of seed light stimulation on the mechanical strength and photosynthetic pigments content in the scorzonera leaves

Abstract

The leaves of scorzonera are vulnerable to mechanical damage due to heavy rainfall or wind. The aim of the study was to determine the impact of pre-sowing exposure of scorzonera seeds to laser light on the mechanical strength of the leaves and the content of photosynthetic pigments. The research material consisted of scorzonera leaves obtained from seeds treated with He-Ne laser light at the wavelength of 632.8 nm, surface power density of 5 mW cm –2 , and exposure time of 1, 5, 10, and 30 minutes. Young’s modulus measurements showed that the leaves of the plants grown from seeds subjected to laser light stimulation were characterized by better mechanical strength compared to the leaves of the control. The highest values ​​of the Young’s modulus were recorded for scorzonera plants grown from seeds subjected to laser light exposure for 10 minutes. Exposure to light for a period of 1, 5 and 30 minutes significantly affected the content of chlorophylls and carotenoids in the leaves relative to the control. The largest increase in the content of photosynthetic pigments was recorded for 1 minute. The improvement in the mechanical strength of scorzonera leaves may reduce their vulnerability to mechanical damage during vegetation.

Keywords

• laser light
• scorzonera
• leaves
• young’s modulus
• tensile test
• photosynthetic pigments