The "murtilla" (Ugni molinae Turcz., Myrtaceae), present in Contulmo Natural Monument (Araucanía Region, Chile), is affected by witches'broom disease, caused by the presence of a phytoplasma in the sieve tubes of the phloem. This phytoplasma affects plants morphoanatomically, producing evident symptoms. Infected branches show reddening of leaves and general dwarfism. In the present study, we compared morphoanatomically and physiologically branches (modules) of murtilla with and without symptoms of witches'broom disease. This was done in order to quantitatively evaluate the actual effect of the infection on adult plants. We cut branches of similar age, with and without symptoms, where we measured fluorescence, chlorophyll content, specific leaf area, stem... |