In vitro rooting of Acca sellowiana microshoots
Acca sellowiana, known as 'Guayabo del País' or 'Pineapple guava', is a small evergreen ornamental fruit tree of the family Myrtaceae, native to Uruguay and south-eastern Brazil. It has excellent agronomical and commercial potential, high nutritional value, and is adequate for fresh consumption as well as for the elaboration of manufactured products. Several genotypes with outstanding fruit size and flavor have been selected in the breeding program for this species in Uruguay. However, the low success achieved so far with conventional vegetative propagation of selected materials is an important limitation for commercial production in our country. Micropropagation has been considered as an alternative for the production of high quality, pathogen-free plant material. Rooting of cuttings and microcuttings of woody species is strongly dependent on the genotype of the donor plant and the ability to root is rapidly lost with ageing of the mother plant. The objective of the present study was to evaluate different alternatives to improve rooting ability of selected materials, in vitro. Selected mother plants were cultivated in a greenhouse and used as source of explants for micropropagation. Explants were established in vitro on Woody Plant Medium (WPM) devoid of plant growth regulators, according to a protocol previously developed in our laboratory for this species. Maximum multiplication rate was achieved with 2.85 µM zeatin riboside. We evaluated different rooting alternatives with two selected plant materials, differing in rooting ability. WPM was used as basal medium, supplemented with 10 µM indole-3-butyric acid (IBA), 100 µM sodium nitroprusside (SNP), 1 mM phloroglucinol (PG), or the combination of 10 µM IBA and 1 mM PG. The material that rooted poorly responded to IBA (60% rooting). However, neither PG nor SNP had a positive effect on rooting of microcuttings.
Ross, S., Pechi, E., Speroni, G., Vignale, B., Speranza, P., Castillo, A. and Cabrera, D. 2017. In vitro rooting of Acca sellowiana microshoots. Acta Hort. (ISHS) 1155:537-542
adventitious roots, Feijoa, micropropagation, nitric oxide, phloroglucinol