Influencia del Ca2+, pH, agar y reguladores de crecimiento en la propagación in vitro de Echinocactus parryi (Engelm)
Resumen
Echinocactus parryi is a threatened and endemic
species of the municipality of Juarez, Chihuahua,
Mexico that presents important limitations for its
propagation. The objective of this study was to evaluate
the effect of growth regulators, calcium concentration
(Ca2+), environmental pH and gelling concentration
in the morphogenetic response of E. parryi. The
seeds were germinated in Murashige and Skoog
(MS) medium at 25% of the concentration of their
salts (¼ MS). Epicotyls were cultured in an inverted
position in media with different concentrations of
6-benzylaminopurine (BAP) (0-10 mg L-1), indole-3-
acetic acid (AIA) (0-0.5 mg L-1), pH 5.7 and 8, Ca2+
(13.2 µM and 26.4 µM) and agar (7 and 10 g L-1).
The highest sprout formation (2.9 sprouts per explant)
was obtained in MS medium with 2 mg L-1 of BAP
combined with 0.5 mg L-1 of AIA, 13.2 µM of Ca2+,
pH 8, and 7 g L-1 of agar, at 120 days of culture. The
sprouts were transferred to MS medium with 2,3,5
tri‑iodobenzoic acid (TIBA) (0, 0.5, 1 and 2 mg L-1)
to induce root formation. The highest rooting (70.5%)
was obtained in medium with 0.5 mg L-1 of TIBA. The
survival of the plants was 58% at 5 months. This is the
f irst report that describes the in vitro regeneration of
E. parryi and constitutes an important advance for its
propagation and conservation.