Submitted to: In Vitro Cellular and Developmental Biology - Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/26/2009
Publication Date: 5/13/2009
Citation: Bell, R., Srinivasan, C., Lomberk, D. 2009. Effect of nutrient media on axillary shoot proliferation and preconditioning for adventitious shoot regeneration of pears. In Vitro Cellular and Developmental Biology - Plant. DOI 10.1007/s11627-009-9196-8. Interpretive Summary: Plant tissue culture, which utilizes mixtures of essential inorganic nutrients in an artificial medium to promote multiplication of shoots, is useful for rapid propagation of pear varieties. It is also an essential technique that provides leaf tissue necessary for genetic transformation and plant regeneration experiments employed for improvement of existing varieties. The most common plant tissue culture media, including those used for pears, are based upon a formula devised by Murashige and Skoog. A preliminary experiment and research on other varieties indicated that this medium might not be the optimum for Bartlett and Beurre Bosc pears. Three additional media were compared with MS for efficiency of shoot muliplication, generation of young expanding leaves optimal for plant regeneration, and subsequent regeneration. The media differed from MS primarily in the total nitrogen concentration, ammonium and nitrate ion concentrations, and calcium ion concentration. Media known as DKW and QL were found to be superior to MS for axillary shoot proliferation of 'Bartlett' and Beurre Bosc' pear cultivars. Leaf explants derived from DKW produced more adventitious shoots than leaf explants from MS and WPM, but was not statistically superior to QL medium. Preferential use of DKW as the basal nutrient medium is recommended for micropropagation for 'Bartlett' and 'Beurre Bosc' to improve both plant multiplication and regeneration.
Technical Abstract: The influence of the basal nutrient composition of plant tissue culture media on axillary shoot proliferation and their preconditioning effect on subsequent adventitious shoot regeneration from leaves was investigated, with the goal of improving both micropropagation and regeneration of 'Bartlet' and 'Beurre Bosc' pear cultivars. Driver-Kuniyuki Walnut (DKW) and Quorin and Lepoivre (QL) basal nutrient mixtures were found to be superior to Murashige and Skoog (MS) and Woddy Plant Medium (WPM) for axillary shoot proliferation. 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 both experiments.