Submitted to: International Symposium on Biotechnology of Temperate Fruit Crops and Tropical Species
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/2005
Publication Date: 9/16/2005
Citation: Bell, R.L. 2005. Preconditioning effect of shoot proliferation medium on adventitious shoot regeneration of pear. International Symposium on Biotechnology of Temperate Fruit Crops and Tropical Species. p. 16.
Technical Abstract: The physiological state of leafe explants is important for high efficiency adventitious transformation and regeneration. The composition of shoot proliferation culture medium and other factors are known to influence micropropagation. This study investigated the effects of culture age, type and concentration of cytokinin and orientation of shoot explants on subsequent shoot regeneration from leaves. Shoot cultures of 'Beurre Bosc' pear were grown on QL basal medium supplemented with either 2.5 or 5.0 uM BA, kinetin, or 2-iP. Shoot explants for proliferation were either in vitro shoot tips including the apical meristem, or in vitro stem sections with three lateral buds. After two, four, and six weeks of culture, the top two youngest expanding leaves were excised and placed on CL regeneration mediuim. Cytokinin concentration and orientation of the explants for proliferation had no significant effect on percent of explants regenerating shoots, but leaves from BA cultures regenerated significantly more than those from kinetin and 2-iP cultures. The differences were greatest for the leaf explants from six week old cultures, and interations involving age and cytokinin were significant.