Efficient plant regeneration from leaves of rapeseed (Brassica napus L.): the influence of AgNO3 and genotype

Abstract

Factors influencing reliable shoot regeneration from leaf explants of rapeseed (Brassica napus L.) were examined. Addition of AgNO(3) to callus induction medium was significantly effective for shoot regeneration in all three genotypes initially tested. When 48 genotypes subsequently were surveyed, a large variation of shoot regenerability was observed, ranging from 100 to 0% in frequency of bud formation and from 7.5 to 0 in the number of buds per explant. A significant correlation (r=0.84) was observed between the frequency of bud formation and the number of buds per explant. The shoot regenerability from leaf explants was not related to that from cotyledonary explants (r=0.28). Histological observations showed that an organized structure developed from calluses produced at vascular bundle tissues after 7 days of culture on callus induction medium, and they developed shoot apical meristems one week after transfer onto shoot induction medium. Regenerated plantlets were obtained 2 months after the initiation of culture and they normally flowered and set seeds. No alterations of morphology or DNA contents were observed in regenerated plants and their S1 progenies.

Regeneration from leaf explants and protoplasts of Brassica oleracea var. botrytis (cauliflower)

“…It remains to be shown whether these shoots develop directly or indirectly from mesophyll cells or vascular parenchyma in cauliflower, given that several studies have shown that brassica adventitious shoots arise from vascular parenchyma cells in seedling and leaf explants (e.g. Hachey et al, 1991;Mukhopadhyay et al, 1992;Sharma et al, 1993;Akasaka-Kennedy et al, 2005). This is interesting as plastid transformants of B. oleracea have been regenerated from leaf explants after biolistics delivery of plasmid DNA (Liu et al, 2007).…”

Robust Circadian Rhythms of Gene Expression inBrassica rapaTissue Culture

“…We next establish molecular assays of clock function, exploiting clock-regulated promoter:LUCIF-ERASE reporters. Agrobacterium tumefaciens-mediated transformation through explant-based callus cocultivation is an efficient method for many Brassica species and varieties, including Brassica napus, B. oleracea, and Brassica juncea (De Block et al, 1989;Akasaka-Kennedy et al, 2005;Arumugam et al, 2007;Bhalla and Singh, 2008). However, efforts to generate transgenic plants of B. rapa have been less successful, limited by low regeneration and rooting rates from callus and also by the inefficiency of vacuum infiltration (Zhang et al, 2000;Xu et al, 2008).…”

Analysis of genetic components of winter oilseed rape ( Brassica napus ssp. oleifera ) regeneration ability under in vitro culture

“…Heritability in the broad and narrow sense was analyzed, respectively, amounting to 0.973 and 0.819 values. Akasaka-Kennedy et al (2005) demonstrated a genetic control of the shoot formation ability for winter oil- Table 4. Heritability in the broad and narrow sense obtained for the four studied traits Trait Heritability in the broad sense Heritability in the narrow sense…”