Effect of nutrient media on axillary shoot proliferation and preconditioning for adventitious shoot regeneration of pears

Abstract

The influence of the nutrient composition of plant tissue culture media on axillary shoot proliferation and their preconditioning effect on subsequent adventitious shoot regeneration from pear leaves was investigated. The goal was to improve both micropropagation and regeneration of 'Bartlett' and 'Beurre Bosc' pear cultivars. DriverKuniyuki walnut (DKW) and Quoirin and Lepoivre (QL) nutrient media were found to be superior to Murashige and Skoog (MS) and Woody Plant Medium (WPM) for axillary shoot proliferation. Shoots on WPM exhibited some chlorosis. Axillary shoot culture on DKW would be preferred to that on QL due to the production of excessively short thin shoots on the latter medium. DKW also was superior to QL and MS for production of young expanding leaves for use as explants in adventitious regeneration. Leaf explants derived from shoot proliferation cultures grown on DKW or QL media produced more adventitious shoots than leaf explants from MS.

In vitro multiplication of pear tree cultivar Cascatense

“…However, they are limited by factors of the physical and chemical microenvironment in the growing containers, such as concentrations of nutrients and growth regulators that can endanger the formation of shoots and/or microplants (BOMMINENI et al, 2001;REED, 2002;CASANOVA et al, 2008). Consequently, the quantity and balance of growth regulators, carbohydrates, and other nutrients are determining factors in the success of in vitro multiplication of plant material (BELL; REED, 2002;RUZIC et al, 2008;MORAES et al, 2004;DOBRÁNSZKI;TEIXEIRA DA SILVA, 2010), as demonstrated by the results in this study.…”

“…protocols have been developed to optimize the in vitro culture conditions for high multiplication rates, both in pear trees (BOMMINENI et al, 2001;REED, 2002;HASSANEN;GABR, 2012;KARIMPOUR et al, 2013) and in other Rosaceae (YASEEN et al, 2009b;SILVA et al, 2011;VUJOVIC et al, 2012). For adequate growth and development to occur during the multiplication phase, it is necessary to control morphogenesis, a process influenced by several factors such as species, cultivar, type of explant, components of the nutrient medium, growth regulators added to the culture medium, and environment (BELL et al, 2009;SILVA et al, 2011).…”

“…For adequate growth and development to occur during the multiplication phase, it is necessary to control morphogenesis, a process influenced by several factors such as species, cultivar, type of explant, components of the nutrient medium, growth regulators added to the culture medium, and environment (BELL et al, 2009;SILVA et al, 2011).…”

“…In the in vitro multiplication of woody plants, buds or shoot tips are normally employed REED, 2002;BELL et al, 2009;HASSANEN;GABR, 2012;KARIMPOUR et al, 2013). The culture media may be either liquid or semisolid, and is made up of mineral salts (macro and micronutrients), carbohydrates, vitamins, and growth regulators (D'ONOFRIO;MORINI, 2005;CIELNIAK et al, 2008;SILVA et al, 2011).…”

“…There are a number of different culture media, each with differing salt and vitamin concentrations according to the needs of the species or cultivar. Media are made into gel with different agents (RODRIGUEZ et al, 1991;REED, 2002;LUCYSZYN et al, 2006;BELL et al, 2009), but the most utilized are MS (MURASHIGE;SKOOG, 1962) and its modifications and dilutions, as well as WPM (Wood Plant Medium) (LLOYD; McCOWN, 1980), QL (QUOIRIN;LEPOIVRE, 1977), and DKW (DRIVER; KUNIYUKI, 1984), the formulations of which are considered most diluted.…”