TITLE:
In Vitro Propagation and Recovery of Eight Apple and Two Pear Cultivars Held in a Germplasm Bank
AUTHORS:
Analí Lizárraga, Marga Fraga, Javier Ascasíbar, María Luz González
KEYWORDS:
Apple Shoots, Pear Shoots, Axillary Bud, Multiplication, Cytokinin, Gene Bank
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.9,
August
18,
2017
ABSTRACT: Eight
apple (Malus x domestica) and two pear (Pyrus communis) traditional cultivars of
commercial interest were selected from the germplasm bank CIAM (Centro de
Investigaciones Agrarias de Mabegondo, NW of Spain) one of the most important
collections of The Iberian Peninsula. In order to define the establishment
protocol, apical buds 1.0 - 1.5 millimetre length of the selected cultivars were
established in solid mineral medium Murashige and Skoog (MS) with modified
vitamins (thiamine 10X) and supplemented with 1 mg·L-1 6-benzyladenine (BA), 0.2 mg·L-1 gibberellic acid (GA3) and 0.3 mg·L-1 of indole-3-butyric
acid (IBA). The highest shoot initiation rates were achieved with apple
cultivar “Principe Grande” (55%)
and “Barburiña” pear
cultivar (50%); the lowest rate was obtained with apple cultivar “Camoesa” (11%).
Initiation rates for shoots culture varied between 22% and 37% for the other
cultivars. The cytokinins BA, zeatin, 2-isopentyladenine (2iP) and thidiazuron
(TDZ) were tested at concentrations of 0, 0.25, 0.5 and 1 mg·L-1 in the
absence or presence of IBA (0.1 mg·L-1) for the multiplication step. For all cultivars,
the highest multiplication rates were obtained with medium supplemented with
TDZ and also in media containing BA. The in vitro rooting success of shoots
in medium with 0.1 mg·L-1 IBA without cytokinins, and the survival rate of
plantlets acclimatized under greenhouse conditions depended on the genotype of
the different cultivars. In vitro propagation of these ten traditional
apple and pear cultivars in NW Spain has not previously been reported.