环境调控对甘薯组培苗光合自养和叶片超微结构的影响

Effect of Environmental Control on Photoautotrophy and Leaf Ultrastructure of Plantlet in vitro of Ipomoea batatas (L.) Lam

以甘薯组培苗为材料,在特定CO2浓度,光合光量子通量密度(PPFD)和相对湿度(RH)条件下,研究其生长发育状况和叶片的超微结构。与传统培养方式相比,在环境因子CO2浓度、PPFD和RH分别调控为800～875μmol·mol-1、250 μmol·m-2·s-1和75%～85%的条件下,组培苗的叶片数、茎粗、单株鲜重、叶鲜重、叶面积、根鲜重、叶绿素含量和根系活力显著提高。无论培养基中有无添加蔗糖,环境调控方式下培养的组培苗,叶片下表皮细胞的气孔大多数处于开放状态,气孔的开度最大达50 μm;叶肉细胞中的叶绿体数目多、体积大,形状较为规则,基粒片层的层数较多,片层垛叠也相对整齐、紧密。结果证明,环境调控技术的应用显著提高再生植株的光合自养能力,促进生长发育。

Carbon dioxide concentration, photosynthetic photon flux density(PPFD) and relative humidity in tissue culture environment were controlled at800-875 μmol·mol-1, 250 μmol·m-2·s-1 and 75%-85% to study the developmentand leaf ultrastructure of plantlets in vitro of Ipomoea batatas Lam. Results showed that the leaf number, stem diameter, plantlet fresh weight, leaf fresh weight, leaf area, root fresh weight, chlorophyll content and root vigour of plantlets in vitro cultured in the controlled environment were improved obviously. Whatever the medium contained sugar or not, most of the stomata of plantlets growing in controlled environment were open, and its maximum was 50 μm, the number and size of chloroplast, grana and lamella were increased. Application of the technique of environmental control would improve the photoautotrophic ability and developmental level of plantlets in vitro significantly.