Figure 2
Elevated auxin levels due to polar auxin transport inhibit shoot organogenesis at the basal end of citrus stem segments. In all pictures, explants are arranged with the apical end facing up and the basal end facing down. (a) After 15 days, untreated ‘Carrizo’ citrange explants (left) had inhibited shoot development at the basal end, whereas explants treated with N-1-naphthylphthalamic acid (NPA) (right) experienced shoot development at both the apical and basal ends of the explant. (b) After 15 days, untreated ‘Eureka’ lemon explants (left) experienced reduced shoot development compared to explants treated with NPA (right). (c) Shoots produced from five untreated ‘Carrizo’ citrange explants (above the white line) were fewer in number and smaller in size compared to shoots from five explants treated with NPA (below the white line). (d) Five of the NPA-treated ‘Eureka’ lemon explants produced more and larger-sized shoots (below the white line) than the untreated controls (above the while line).
