甘蔗胚性愈伤组织发生与发育的组织细胞学观察

运用石蜡切片染色和显微技术相结合的方法,对FN15和ROC22两个不同基因型甘蔗品种,在心叶诱导愈伤组织和愈伤组织继代过程的不同阶段,对愈伤组织胚性细胞、体细胞胚和芽原体的发生与发育进行了研究。结果表明,愈伤组织来源于切口部位、韧皮部、维管束鞘或外皮层具有活力潜能的薄壁细胞,此种愈伤组织多数为胚性细胞。基因型FN15可从心叶直接诱导出体细胞胚,而基因型ROC22则需继代培养后才发生体细胞胚。从愈伤组织表型分析,浅黄色愈伤组织多数为胚性细胞;金黄色和乳白色愈伤组织多数是已分化的各种类型的体胚;褐色愈伤组织,只有极少量细胞具有分裂能力,最终也能分化出小芽;透明状愈伤组织一般无细胞质,也不具分裂能力。因此应选择浅黄色的愈伤组织作为转基因准备受体。

Cytohistological Examination of Embryogenesis in Sugarcane

The quality of calli is the basis and precondition of successful transformation in sugarcane. Quality evaluation of sugarcane calli based on the cytohistological examination was limited. Cytohistological examination of callus induction and embryogenesis from two different genotypes of sugarcane was conducted via the combination of paraffin section. The results showed that the calli induced from parenchyma cells, phloem, bundle-sheath and epidermis of the young leaf explants were likely to develop into embrygenic calli, and that the embryogenesis of two different genotypes differed in culture conditions and durations. The embrygenic callus could develop from the young leaf explants directly for FN15 and from the calli after first subculture for ROC22, respectively. The main results of the appearances and textures of the callus associated with embryogenesis were as follows. Most thin yellow calli were embrygenic cells. Most golden yellow calli were developed to systemic embryo with different types. For brown calli, only few cells were embrygenic and could develop to gemmule. No cytoplasm was observed commonly in limpid calli. Thus, if the purpose was to prepare calli for genetic transformation, thin yellow calli could be the best selection. The results provided technique basis for selection and preparation of calli with high quality.