Jiménez V M, Guevara E, Herrera J, Bangerth F
Inst. Obst-, Gemüse- und Weinbau (370), Universität Hohenheim, 70593 Stuttgart, Germany e-mail:
CIGRAS, Universidad de Costa Rica, 2060 San Pedro, Costa Rica, , , , , , CR.
Plant Cell Rep. 2001 Jan;20(1):92-100. doi: 10.1007/s002990000280.
Embryogenic nucellar callus cultures of different Citrus species and cultivars growing in hormone-free medium were transferred to medium containing either sucrose or glycerol as the only carbohydrate source. Glycerol has been reported to induce further development of Citrus somatic embryos, while in the presence of sucrose they continue to proliferate in an 'undifferentiated' manner. The endogenous hormone levels of the cultures were evaluated after 2 and 5 days to characterise the initial steps of embryo development. In most cases, differences among treatments were observed only after 5 days of culture. Higher cytokinin levels were found in most of the cultures transferred to the glycerol-containing medium. The effect of ageing sweet orange cultures on their endogenous hormone levels was determined by leaving them in the original culture medium without subculturing for 60 days. While no changes were observed in the free indoleacetic acid and gibberellin contents, lower levels of abscisic acid and cytokinins were found in the aged cultures than in those transferred at the normal interval, every 30 days. The endogenous hormone contents of Citrus callus of different genotypes were compared. Significant differences were observed in the levels of all hormones evaluated, even when the in vitro ontogeny of the different genotypes was very similar.
将在无激素培养基中生长的不同柑橘品种和栽培种的胚性珠心愈伤组织培养物转移到以蔗糖或甘油作为唯一碳水化合物来源的培养基中。据报道，甘油可诱导柑橘体细胞胚进一步发育，而在蔗糖存在的情况下，它们会以“未分化”的方式继续增殖。在培养2天和5天后评估培养物的内源激素水平，以表征胚胎发育的初始步骤。在大多数情况下，仅在培养5天后才观察到处理之间的差异。在大多数转移到含甘油培养基中的培养物中发现了较高的细胞分裂素水平。通过将衰老的甜橙培养物留在原始培养基中60天不继代培养，来确定其对内源激素水平的影响。虽然游离吲哚乙酸和赤霉素含量没有变化，但与每隔30天正常继代转移的培养物相比，衰老培养物中的脱落酸和细胞分裂素水平较低。比较了不同基因型柑橘愈伤组织的内源激素含量。即使不同基因型的体外个体发育非常相似，在所评估的所有激素水平上也观察到了显著差异。
