* Morphological and physiological attributes were assessed to elucidate the underlying mechanisms of ozone (O(3)) sensitivity in a highly sensitive species, cutleaf coneflower (Rudbeckia laciniata var. digitata). * Foliage at the same height in the canopy on paired O(3)-sensitive and -insensitive cutleaf coneflowers was assessed for level of foliar symptoms, stomatal density, stomatal responsiv...

Visible injury caused by ozone is recorded every year in native plant species growing in Great Smoky Mountains National Park (USA). One of the most sensitive species, cutleaf coneflower (Rudbeckia laciniata L.), shows great variation in symptoms between and within populations but the causes of this variation and its ecological significance are currently unknown. This paper presents data relatin...

Easwar Natarajan,* John D. Omobono II,* Zongyou Guo,* Susan Hopkinson, Alexander J.F. Lazar, Thomas Brenn, Jonathan C. Jones, and James G. Rheinwald* From the Departments of Dermatology * and Pathology, Brigham and Women’s Hospital, Harvard Skin Disease Research Center, Harvard Medical School, Boston, Massachusetts; and the Department of Cell and Molecular Biology, Northwestern University Medic...

abstract growth retardants are new chemical organic compounds that increase period of flowering, leave chlorophyll, lateral shoot number, flower number and decrease vegetative growth. they also increase dry, cold and heat tolerance. paclobutrazol and cycocel are examples of these compounds. this study was conducted to evaluate the effect of paclobutrazol and cycocel on some quantitative and qua...

The magnetic field (MF) is considered as a biophysical treatment to change the growth and development parameters. Current research was carried out to evaluate the effect of different intensities of MF (0, 45, 60, 70 and 75 mT) on seed germination and some morphologic and physiologic parameters of Rudbeckia hirta L. in dry and humid conditions for 30 min. Results showed that the MF trea...