Influence of light intensity on germination, vegetative development, and reproduction of three species of Asteraceae native to Kansas

Plants are strongly influenced by a continuously changing light environment and their ability to detect light provides them vital information for their survival. However, most of the studies on photobiology are about commercial species and little is known about species native to Kansas and its region. Therefore, our objective was to analyze responses of three Asteraceae species native to Kansas under different light intensities during germination, vegetative development, and flowering. Seeds of Ageratina altissima, Eupatorium purpureum, and Solidago ulmifolia were measured for germination daily in conditions of dark, approximately 10%, 50%, and 100% of natural light. Seeds were later planted in soil and exposed to the same light conditions, and height, number of leaves, and chlorophyll (SPAD) were measured. Preliminary results show that A. altissima was the fastest species for germination and its germinability was consistent across light treatments. Germination in S. ulmifolia was also consistent across light treatments. For E. purpureum, germinability was higher in the light treatments than in the dark. A. altissima plants growing in 50% and 100% of light were taller and had more leaves than plants growing under 10% of light. Conventional plant responses to low light include growing taller under shaded conditions, although these plants responded differently. Most habitats in the prairie are exposed to bright sunlight and these results indicate these Asteraceae species are adapted to live and grow under bright light