观赏植物白花龙的离体快繁条件筛选

Screening for in vitro rapid propagation conditions of ornamental plant Styrax faeri Perk.

【目的】筛选白花龙(Styrax faberi Perk.)的离体快繁最佳条件,为白花龙的推广种植及生态环境修复提供参考依据。【方法】以切除或带胚乳的白花龙种子为外植体、MS为基本培养基,添加不同浓度GA_3进行无菌萌发;以种子无菌萌发的茎段为外植体、MS为基本培养基,采用正交试验设计,筛选适宜白花龙丛生芽增殖培养的最佳6-BA、NAA和TDZ组合;以丛生芽增殖获得的幼苗为外植体、MS或1/2MS为基本培养基,添加不同浓度的IBA,采用直接或间接生根法,筛选白花龙组培苗生根的最佳基本培养基、IBA浓度和生根方法。【结果】带胚乳的白花龙种子在添加不同浓度GA_3条件下萌发15 d后子叶开始褐化,最终全部死亡;切除胚乳的白花龙种子在无激素条件下也可萌发,但以在MS+2.0 mg/L GA_3培养基中萌发率最高,达97.5%。在继代增殖阶段,白花龙丛生芽在MS+0.5 mg/L 6-BA+0.05 mg/L NAA培养基中增殖系数最大,为5.7。在生根阶段,带两个节的白花龙茎段在200.0 mg/L IBA溶液中浸泡15 min后转接至1/2MS空白培养基的生根率最高,达93.3%,平均生根数为7.1条。【结论】切除胚乳的白花龙种子在MS+2.0 mg/L GA_3培养基中萌发率最高,其萌发的茎段在MS+0.5 mg/L 6-BA+0.05 mg/L NAA培养基中增殖系数最大;采用间接生根法,可获得生根效率较高、适应规模化生产的白花龙组培苗。

【Objective】The objective of this study was to screen the optimal condition for in vitro rapid propagation of Styrax faberi Perk.to provide the reference for S.faberi planting promotion and eco-environmental modification.【Method】The seeds of S.faberi with or without endosperm were used as explants,MS as the basic medium and different concentrations of GA3 were used for aseptic germination of seeds.Stem of aseptically germinated seeds were used as explants,MS was used as the basic medium,the optimal combinations of 6-BA,NAA and TDZ were screened for proliferation of clustered shoots of S.faberi by orthogonal experiment.Seedlings obtained by propagation of clustered shoots as explants,MS or 1/2MS as the basic medium,different concentrations of IBA were added,direct or indirect rooting method were used to screen optimal basic medium,IBA concentration and rooting method for the rooting of S.faberi.【Result】The results showed that cotyledon of S.faberi seeds with endosperm on media with different concentrations of GA3 were browning when germinated after 15 d and then died.Seeds without endosperm could germinate even on the medium without any hormone.The optimal medium for seed germination without endosperm was MS+2.0 mg/L GA3,and the germination rate was up to 97.5%.At the stage of subculture multiplication,the optimal medium of clustered shoots proli-feration was MS+0.5 mg/L 6-BA+0.05 mg/L NAA,where the proliferation coefficient was 5.7.At rooting stage,when the stem segments with two sections were soaked in IBA solution of 200.0 mg/L for 15 min and then transferred to 1/2MS blank medium,the rooting rate was the highest,reaching 93.3%,and the average number of roots was 7.1.【Conclusion】The seed germination rate of S.faberi is the highest in MS+2.0 mg/L GA3 medium and the proliferation coefficient of S.faberi clustered shoots is the highest in MS+0.5 mg/L 6-BA+0.05 mg/L NAA medium.Indirect rooting method can be used to obtain S.faberi tissue culture seedlings with high rooting efficiency and large-scale production.