Effect of Picloram on Organogenesis in Detached Leaves ofEcheveria elegansBgr.

Abstract

The effect of picloram (4-amino-3,5,6-trichloropicolinic acid) on regeneration of detached leaves ofEcheveria elegansBgr. was studied. Picloram stimulated callus production at all concentrations. Low concentrations of 1 to 15 ppmw picloram did not affect shoot organogenesis and the same, however, stimulated rhizogenesis. Inhibition of both root- and shoot-organogenesis was noticeable at concentrations below 20 ppmw and above. Roots increased in number at all picloram concentrations below 40 ppmw, the maximum number being at concentration of 15 to 20 ppmw of the herbicide. Observations indicated that root elongation was considerably suppressed. Picloram-induced callus contained mature parenchyma cells devoid of contents and considerable amount of tissue disruption was noticed. Irregular vascular differentiation and obliteration of tissues particularly in the region of tracheary elements, were obvious. Although normal apical organization was lacking in root primordia and in arrested short roots, these elongated normally into mature roots when they were transferred to water, thus indicating that apical meristems were not severely affected by picloram.

Effects of Light and Hormones on Regeneration of Crassula Argentea From Leaves

“…In Kalanchoe tubiflora auxin promoted root formation on epiphyllous buds (Nanda and Jain, 1972;author uses synonym Bryophyllum tubiflorum). In the wound-response type of plant, Echeveria elegans, an auxinlike herbicide, picloram, inhibited shoot formation and promoted root growth at all concentrations (Raju and Grover, 1976).…”