【作者】 李景云；

【导师】 李伯林；

【作者基本信息】 广西师范大学 ， 生态学， 2003， 硕士

【摘要】 本试验运用热处理和茎尖培养相结合来诱导荔浦芋脱毒苗，进行组培脱毒技术研究，探讨茎尖脱毒的最佳条件以及建立快速繁殖体系，以期为无毒种苗的工厂化生产提供科学理论依据和关键技术。按常规方法栽培脱毒苗，与传统球茎苗对比产量和品质，为脱毒苗的推广提供依据。 将荔浦芋无根苗接种到MS+3％蔗糖+6-BA 4 mg／l(若无特别说明以下单位均为mg／l)+NAA 0.05的液体培养基中，置于38.7℃恒温箱中培养15天，成活率为80％。将热处理15天仍存活的无根苗在解剖镜下剥取0.5—0.6mm大小的茎尖作为外植体。电镜观察表明：热处理15天，0.6mm大小的茎尖除去了危害芋艿最强烈的芋花叶病毒。通过激素配比试验，筛选出最佳培养基组成。试验结果表明：MS+3％蔗糖+0.7％琼脂+6-BA 0.5+NAA 0.1为茎尖诱导最佳培养基，成活率可达83.33％，30天时，茎尖转为绿色，基部膨大，茎尖伸长呈小芽状；MS+3％蔗糖+6-BA 4+NAA 0.05+spm(精胺)20和MS+3％蔗糖+6-BA 5+NAA 0.05+spm 20交替使用，既可保持较高的繁殖系数，又可壮苗，成为快速繁殖的最佳培养基；1/2MS+2％蔗糖+0.1％活性炭+NaAA 0.05+IBA 1.0为最佳生根培养基，植株生根率可达98％，无根苗接种后，根系早生快发，根粗而多，根毛多，植株整齐一致，生长健壮，叶色浓绿。MS+0.7％琼脂+5％蔗糖+NAA 0.5+6-BA 2.0可诱导较大的微型芋，微型芋比再生植株抗逆性强，可以减少病毒的侵染机率，而且更易于存活，更利于生产。 茎尖苗叶绿素含量高于对照，这是茎尖苗生长旺盛、产量增加的物质基础和生理基础。茎尖苗抗逆性强，芋疫病和芋软腐病发病程度较轻。茎尖苗第一代的产量低于对照(约50％)，但茎尖苗二代产量比对照高14.10％。品质有所提高，肉质更松软、细腻，香味较浓，口感好。茎尖苗母芋形状呈纺锤形，个体均匀，商品价值高。更多还原

【Abstract】 The method of heat treatment with shoot-tip culture was used for eliminating dasheen mosaic virus of Lipu-taro (Colocasia esculenta L. Schott.). The optimun conditions for shoot-tip induction and rapid propagation were established. These approaches provided some theoretical bases and key techniques for rapid propagation of Colocasia esculenta L Schott. Cultivated shoot-tip seedlings in conventional method and compared with the controls, the results supplied some bases for shoot-tip seedling popularization.The root-free seedlings were inoculated into the MS liquid medium supplemented with 3% sucrose, 4 mg/1 6-BA and 0.05 mg/1 NAA, and were put in therm.ostatic box. The temperature was kept 38.7 for 15 days. The survival rate was 80%. The electron microscope was used for virus detection of the plantlets. Results showed that the plantlet did not carry dasheen mosaic virus with exfoliating shoot-tip. With 0.5-0.6mm shoot-tips as explants, a series of optimization experiment for cultural medium composition, concentration of phytohormone was investigated with a view to accelerate the propagation of virus free plants. The obtained results indicated that the optimized medium for .shoot-tip induction was Ms medium added with 3% sucrose, 0.7% agar, 0.5 mg/16-BA and 0.1 mg/1 NAA. The survival rate of shoot-tip was over 80%. The shoot-tip turned green, the base of it swelled and it elongated as a bud.MS medium with 3% sucrose, 4 mg/1 6-BA,0.05 mg/1 NAA, 20 mg/1 spermine, and MS medium with 3% sucrose, 5 mg/16-BA,0.05 mg/1 NAA, 20 mg/1 spermine were the optimum media for proliferation. They were used alternatively, which could keep high propagation index and keep seedling healthy. The roots were induced when adventitious buds were cultured on 1/2 MS medium with 2% sucrose, 0.1% activated carbon, 0.05 mg/1 NAA and 1.0 mg/1 IBA. The rate of root formation was 98%. After the seedlings were transplanted to soil, they grew robustly and had a good root system and robust green leaves. The medium MS+0.05 mg/1 NAA+0.7% agar+5% sucrose +2.0 mg/1 6-BA could induce bigger mini-taro.The chlorophyll content of shoot-tip seedlings was higher than that of virus infected plants. The case of leaf blight of taro and soft rot of taro was slighter. The corm-yield showed the first generation shoot-tip taro was decreased by 50%, but the second generation was increase 14.10%. Compared with control, the quality of corms of shoot-tip taro had improved. With its quality improved, it had softer and smoother flesh, smelled aromatic and tasted enjoyable. The mother taros of shoot-tip seedlings were like spindle, and the individual was even. The merchandise value was high.更多还原