罗汉果胚性愈伤组织的诱导及植株再生

Embryonic callus induction and plantlet regeneration of Siraitia grosvenorii

为建立罗汉果高频再生体系,以无菌萌发种子的子叶为外植体,对胚性愈伤组织的诱导及植株再生进行研究。结果表明,不同6-BA与2,4-D或NAA配比均能诱导罗汉果子叶形成愈伤组织,诱导率为100%,但NAA比2,4-D更有利于罗汉果胚性愈伤组织的诱导。诱导子叶胚性愈伤组织的最适培养基为MS+6-BA 1.0 mg/L+NAA 0.5mg/L,诱导率为76%。罗汉果胚性愈伤组织为淡黄色或黄色,结构松散,呈颗粒状。2.0 mg/L TDZ能有效促进不定芽的分化,分化率为83.3%。组织细胞学观察发现,子叶胚性愈伤组织通过器官发生途径再生植株。随着愈伤组织表面逐渐转绿,其内部细胞首先分化形成维管组织,然后出现瘤状结构的外表面。在瘤状结构內靠近表层的部位有多个分生细胞中心,分生细胞中心向外分化形成不定芽。

The effects of different kinds and concentrations of hormones on embryonic callus induction and plantlet regeneration were studied by using the aseptic seedling＇s cotyledon from the seeds of Siraitia grosvenorii as explants for setting up the effective regeneration system. The results indicated that the callus induction rate reached 100% under the different proportion of 6-BA and 2, 4-D or 6-BA and NAA. NAA was more suitable than 2, 4-D for embryonic callus induction. The optimum medium for embryonic callus induction was MS＋6-BA 1.0 mg/L＋NAA 0.5 rag/L, and the induction rate reached 76%. The friable, granular, light yellow or yellow embryonic callus was selected. The optimum concentration of TDZ for differentiation of adventitious buds was 2.0 mg/L, with the differentiation rate 83.3%. Histo-cytological observation showed that regenerated plants were produced via organogenesis. The vascular tissue was formed firstly in inner layer of embryonic callus when the surface of embryonic callus turned green. Many vessels were observed in the green nodule. With further development, multiple meristamic centers could be found in area of near surface and they developed adventitious buds finally.