Occurrence of Morphological and Anatomical Adaptive Traits in Young and Adult Plants of the Rare Mediterranean Cliff Species Primula palinuri Petagna

Figure 5

Photomicrographs of root cross-sections of P. palinuri plants developed under controlled conditions (a)–(g) or field-grown (h)–(r) and viewed under light and epifluorescence microscopy: (a)–(c) primary root of a very young plant; (b)–(g) adventitious root of a very young plant; (h)–(n) lateral roots from rhizomes of adult plants; (o)–(r) tie-rod roots from rhizomes of adult plants. UV-microscopy evidenced the blue fluorescence of endodermal Casparian bands (f), (i) and (q) of exodermal cell walls (e), (g), (n), and of subepidermal suberized layers (r). Phenolic compounds are evidenced by the yellow fluorescence (q) and (r). Bars are 20 μm in (a), (b), (f), (g), (i), (l)–(n), and (q), 50 μm in (c)–(e), (h), (p), (r), and 100 μm in (o).