菊花脑花器官的离体培养

Floral organ in vitro culture of Chrysanthemum nankingense

[目的]研究菊花脑(Chrysanthemum nankingense)花蕾再生不定芽的机制,构建菊花脑再生体系。[方法]以菊花脑花蕾为试材,研究花蕾大小、生长调节剂浓度和花器官类型对不定芽再生的影响,同时采用常规石蜡制片法,对不定芽再生过程进行组织学观察。[结果]直径为0.4 cm的花蕾最适于诱导不定芽再生;花蕾外植体的最适再生培养基为MS+2.0mg·L-16-BA+0.25 mg·L-1NAA,再生率达66.5%,平均不定芽数为4.9。花托的再生率为42.6%,舌状花、管状花再生率分别为16.7%和13.1%,子房仅分化出少量芽体。组织学观察表明,花蕾中再生不定芽的部位为花托。不定芽的最适生根培养基为1/2MS+0.2 mg·L-1IBA,生根率和移栽成活率均为100%。[结论]菊花脑花蕾再生不定芽属于器官间接发生途径,以花蕾为外植体可构建高效稳定的再生体系。

[Objectives]Studying the regeneration mechanism of flower bud of Chrysanthemum nankingense,establishing its regeneration system. [Methods]Some factors including size,plant growth regulators combinations and floral organ types were studied on flower bud of C. nankingense for shoot regeneration,meanwhile,through the conventional paraffin method,histological observation about the whole process of regeneration was conducted. [Results]The optimal size of flower bud for differential was 0.4 cm,and the optimal differential medium was MS＋2.0 mg·L^-16-BA＋ 0.25 mg·L^-1NAA,which resulted in the highest regeneration rate（ 66.5%） and highest average number of adventitious bud（ 4.9）.Further analysis revealed that regeneration rate of torus was 42.6%,of ray flower and tubular flower was 16.7% and 13.1%,respectively,while only a small amount of buds differentiated from ovary. Through histological observation of flower bud,the adventitious buds originated from torus. The optimal rooting medium was 1 / 2MS＋0.2 mg·L^-1IBA and the rooting rate and survival rate reached 100%. [Conclusions]The adventitious buds regeneration in flower bud belonged to indirect organogenesis,and taking flower bud as explant would contribute to a high efficient and stable regeneration system for C. nankingense.