【作者】 马东明；

【导师】 郭玉海；

【作者基本信息】 中国农业大学 ， 作物栽培学与耕作学， 2005， 硕士

【摘要】 本实验从管花肉苁蓉种子脱离寄主条件下的离体萌发和吸器形成的形态学入手,研究了多种不同的前处理方式（层积、去种皮、氧化剂次氯酸钠处理）、外源植物生长调节物质以及与寄主试管苗的根共培养等不同条件对管花肉苁蓉种子萌发的影响,寻找了诱导种子萌发的有效方法。实验中利用管花肉苁蓉的寄主柽柳容易离体快速繁殖的特点,研究了寄主柽柳试管苗所生的根对管花肉苁蓉种子萌发、吸器形成乃至寄生的影响,初步定性了管花肉苁蓉种子萌发刺激物质。然后以组织培养方式建立寄主柽柳的离体快速繁殖体系,用去种皮的种子对柽柳试管苗所生的根进行接种,建立起管花肉苁蓉种子与柽柳试管苗的离体接种体系。取得的主要结果如下: 1.培养两周后种子开始萌动,首先胚根从软化的内种皮的种孔端伸出,接着形成芽管状物,之后芽管状物逐渐伸长;17天后初生吸器开始发育,厚的带状表皮分化出若干吸根毛;在初生吸器顶端带状表皮围成窝状,表皮上的褶皱和窝内分布有乳头状突起.芽管状物延伸至4mm停止其发育。去种皮种子的种子萌发和初生吸器形成为露白—突起（圆锥状）—芽管（细长）—芽管增粗—基部膨大顶端变细的过程。 2.不同的前处理方式（层积、去种皮、氧化剂次氯酸钠处理）、外源细胞分裂类物质对管花肉苁蓉种子萌发率的提高有显著的作用;赤霉素使去种皮种子萌发的启动提前,并且高浓度的赤霉素可以使未去种皮种子萌发率有显著的提高。将层积后种子去种皮,用2%NaClO处理8分钟后培养在添加NAA0.1mg/L、KT0.5 mg/L和GA₃ 0.5mg/L的1/2MS培养基上萌发率可达35.5%。寄主试管苗的根对种子萌发率的提高也有显著的作用,与种子共培养时种子萌发率可达31.6%。 3.以组织培养方式建立起寄主柽柳的离体快速繁殖体系,用溶有200 mg/L亚甲基蓝指示剂的MS培养基来研究指示剂与寄主试管苗根分泌物的反应。亚甲基蓝在有寄主根生成的培养基中褪色,而在未生根的对照中仍为蓝色。结果初步说明一种还原性的氢醌为管花肉苁蓉的种子萌发刺激物质,它通过氧化还原反应机制而起作用。 4.用去种皮的种子对柽柳试管苗所生的根进行接种,用体视显微镜观察接种情况并用整体透明方法观察侵染情况,观察到管花肉苁蓉的吸器与寄主柽柳的木质部相连接。实验结果说明管花肉苁蓉种子成功地对寄主根进行侵染。从而证明通过寄主柽柳的离体快速繁殖得到的试管苗与管花肉苁蓉种子的共培养能够建立管花肉苁蓉—柽柳接种复合体。更多还原

【Abstract】 In vitro morphology of seed germination and haustorium formation in Cistanche tubulosa（Schenk） R.Wight without the host was studied firstly,effects on seeds germination with various fore treatments（chilling, decortication, treatment with oxidant NaClO）、 extraneous plant growth regulator and conjunct culture of seeds with radicated host tube seedlings were investigated in order to search effectual methods of seed germination inducement .Since C.tubulosa’s host Tamarix chinensis Lour is prone to rapidly propagate, effects of roots of C. tubulosa’s tube seedling on seeds germination haustorium formation and parasitism were investigated, we elementarily determinate the nature of Germination stimulants in C.tubulosa. Then an system of in vitro rapid propagation of Tamarix chinensis Lour was established through tissue culture, seed coats have been peeled off before seeds were inoculated on root of tube seedling of Tamarix chinensis, thus an in vitro inoculation system of tube seedling of Tamarix chinensis Lour using seeds of Cistanche tubulosa （Schenk） R.Wight was developed .The results are as follows:1. Seeds began to geminate after two weeks. Radicle elongated out of the micropylar end of the soften endopleura, formed germ-tube-like organ, and then elongated gradually. Seventeen days later, elementary haustoria began to develop and several haustorial hairs were differentiated from thick ribbon epiderm which formed fossae among apex of elementary haustoria. Papillary protuberance known as papillae scattered on winkles of epiderm and in fossae. When they elongated till 4 mm , germ-tube-like organs ceased development. The process of decorticated seeds germination and haustorium formation is as follws:sprouting—protuberance（tapered shape） —formation of germ tube（slightness） —germ tube growing widely—intumescence in proximal end — attenuation in acropetal end.2.Various fore treatments（chilling、 decortication、 treatment with oxidant NaClO） and extraneous cytokinin play an active part in promoting seed germination rate,startup of germination in decorticated seeds with GA₃ treatment was ahead of schedule than control, treatment of nomal seeds with GA3 at high concentration can improve rate of germination remarkablelly. Stratified seeds were decorticated and soaked in 2%NaClO eight minutes,then they were sown on 1/2 MS medium solidified with agar supplemented with NAA 0.1mg/LN KT 0.5 mg/L and GA₃ 0.5 mg/L,seed germination rate may add up to 35.5%. Roots of tube seedling of Tamarix chinensis can increase seed germination rate remarkablely, seed germination rate may reach 31.6% when seeds were grown on substrate with radicated host tube seedlings.3. The system of in vitro rapid propagation of Tamarix chinensis Lour was established through tissue culture, then investigation was made on interaction between methylene blue and secretions of roots of host test tube seedlings in MS medium solidified with agar supplemented with 200 mg/L methylene blue. Methylene blue faded in culture medium with the presence of host roots, whereas control without the development of host roots did not fade. The experimental results indicated that a kind of deoxidized hydroquinone which functioned through a mechanism of the redox reaction was identified as germination stimulants of Cistanche tubulosa.4. Seed coats have been peeled off before seeds were inoculated on root of tube seedling of Tamarix chinensis, investigations on inoculation were carried through by stereo microscope and observations on infection were done by means of whole clearing method. Haustorium of Cistanche tubulosa and xylem of host Tamarix chinensis were jointed, results indicated that in vitro infection onhost roots with seeds of Cistanche tubulosa was achieved successfully. Thus cistanche tubulosa-Tamarix chinensis inoculation complex can be established through culture of seeds of Cistanche tubulosa together with radicated Tamarix chinensis Lour.更多还原