Heliotropic movements are characterized as diaheliotropism (to
track the sun) or paraheliotropism (to avoid the sun). A species
may show both types of movements as directed by the environment (high leaf temperature, soil and water potential of plant,photosynthetic photon flux density, PPFD) and specific geno-
types (Charzewska, 2006; Rakocevic et al., 2010). In sunflower
(Helinathus annuus L.), pulvinal tissues around the stem induces
heliotropic movements in response to the external environment