Use of TIBA and BAP on Coffea arabica clones to induce sprouting for micro-cutting
Coffea arabica plants were cloned in vitro from leaf explants through somatic embryogenesis. TIBA (2,3,5-triiodobenzoic acid) and TIBA+BAP (6-benzylaminopurine) solutions were applied on acclimatized plants produced in vitro (PPIV) in order to evaluate the utility of those plant growth regulators to amplify the clones and reduce the costs of micropropagation. Catucaí 567 and Siriema clone 3, 1.1 year old, were decapitated and sprayed with hydro-ethanolic solutions of TIBA (200, 600 and 1000 mg L-1) or 1000 mg L-1 TIBA + 60 mg L-1 BAP or water-ethanol only. Vitroplants tested were 320, being 8 plants per cultivar per treatment with 4 replicas. Plants were maintained in greenhouse, under controlled temperature and humidity. Six months later orthotropic sprouts classified as apical or sub-apical and up to or higher than 1 cm, were excised. For sprouts higher than 1 cm, length and the number of nodes were recorded. Micro-cuttings were prepared by taking nodal segments higher than 1 cm and rooting. Nodal segments averaged 1.7 cm in length. Treatments did not affect apical sprouting, which was 1.0 in plants sprayed with TIBA+BAP and 0.8/PPIV elsewhere. Despite absence of statistical significance, a trend to inhibition of apical sprouting accompanied the increase in TIBA concentration. On the contrary, sub-apical sprouting was significantly (P=0.05) stimulated with TIBA. A trend to stimulation of sub-apical sprouting accompanied the increase in TIBA (R=0.351; P=0.183), principally for Catucaí vitroplants (R=0.784; P=0.021). In average, 2.7 and 3.3 sprouts/PPIV were induced with the two higher concentrations of TIBA and with TIBA+BAP, respectively. Survival was 89%. From 707 micro-cuttings, 96% rooted in 90 days. TIBA, an anti-auxin, probably contributed to interrupt apical dominance and BAP stimulated secondary meristem activity.
Angelo, P.C.S., Baldim, D.S., Neves, P.F.C., Lacerda, J.R., Silva, J.M.D., Couto, I.E., Bueno, I.F., Carvalho, C.H.S., Borato, P.B. and Paiva, A.C.R.S. (2018). Use of TIBA and BAP on Coffea arabica clones to induce sprouting for micro-cutting. Acta Hortic. 1224, 67-72
coffee, micropropagation, acclimatization, cuttings