【作者】 陈灿；

【导师】 黄璜；

【作者基本信息】 湖南农业大学 ， 作物信息科学， 2010， 博士

【摘要】 本研究对不同的水稻品种(系)的化学诱变后代(M1-M3),分别从茎秆的组织结构、剑叶气孔、发芽特性、幼苗生长、水稻突变、主要农艺性状、生理生化、光合特性进行了分析和探讨。特别是系统地研究了不同诱变剂及浓度对水稻组织结构、细胞水平的影响。通过试验以期了解化学诱变对水稻的诱变效应和机理,为今后提高水稻育种水平提供依据。主要研究结果如下：1化学诱变对水稻品种(系)不同后代茎秆组织结构的影响为表述简便,将髓腔、维管束、气腔统称为“管道”。各诱变处理的早稻维管束数量,均为湘早籼33号>R402>R974,且不论品种(系)或代别,均比CK减少；而在湘早籼33号,均为M3代>Mz代；其差异均达显著或极显著水平。在中稻明恢63,均只有低浓度的NaN3使管道面积大于CK处理；晚稻湘晚籼13号及R259,各管道面积比CK增加者约占一半。仅MNU、EMS、NaN3三者的高浓度增加稻茎壁厚度。总之,诱变处理一般使茎秆组织结构性能下降。2不同水稻品种(系)诱变后代剑叶气孔特性的变化对照处理的气孔密度,为明恢63>R259>湘晚籼13号,但前二品种(系)间无显著差异。用MNU、EMS各浓度处理,湘晚13号气孔密度均大于对照CK；在R259和明恢63气孔密度均少于对照CK。3化学诱变对水稻发芽特性及幼苗生长的影响早、晚稻6个品种(系)中,除R974的低浓度处理外,其他所有所有处理的发芽势、发芽率均比CK降低；除MNU的部分处理外,所有其他处理的发芽指数和活力指数也均降低CK；约半数的MNU处理根长、芽长比CK增加；EMS及MNU各处理的叶数、叶面积、苗高、叶挺长、分蘖数、秧基宽、总根数均比CK减少；各药剂处理均显著抑制出苗率和成苗率；且随诱变剂浓度提高而增强。早稻耐高浓度药力更低。4不同水稻品种(系)诱变后代株高、分蘖的变化化学诱变处理的平均株高均低于CK,有显著差异；EMS的致矮效果尤为明显。平均分蘖数基本上诱变处理高于CK,尤以高剂量的NaN3和EMS明显。分蘖数与株高一般无明显相关性。经处理的各品种的株高和分蘖的变化过程均各为一定的“生长型”；早稻品种(系)株高和分蘖数呈S型曲线增长,中、晚稻品种(系)基本上呈幂函数方程式增长。5化学诱变剂对水稻突变效应的影响经诱变处理的变异株的出现率,品种(系)间一般相差不大；但高浓度>低浓度；M2代>M1代>M3代,这3代分别为：矮化株3.0%、3.53%、1.4%,多蘖株2.34%、3.3%、1.2%,叶色变异株2.49%、1.48%、0.46%,早穗株0.51%、1.59%、0.46%。EMS处理的突变率略高于其他2种化学诱变剂。不同浓度间,高剂量效应更明显。矮秆突变株通常植株过矮,叶片扭曲,穗伸出度差、空粃粒多,抗性较弱。叶色突变株通常叶绿素含量低,细胞膜透性增大,电导率增加,MDA含量上升,根系活力下降,光合产物积累少。6不同水稻品种(系)诱变后代生理生化特性的变化测定了处理后各晚稻品种(系)各世代不同生育期的MDA、可溶性糖、SOD、POD、CAT、相对电导率、根系活力等生理生化指标值及各值与根系活力的相关性。各世代的生理生化敏感性为M1>M2>M3；而M1代的损伤效应最大；在M2和M3代逐代有所减弱。品种(系)的敏感性为湘晚13>明63>R259；生育期之间差异不明显。诱变对水稻植株地下部分的负效应比地上部分大；诱变对3种酶活性的影响程度表现为POD>CAT>SOD。化学诱变对水稻体内的MDA和可溶性糖含量影响的持续效应最长。7化学诱变剂对水稻叶绿素相对含量及叶绿素荧光的影响诱变处理与否,叶绿素相对含量SPAD值均为R259>明恢63>湘晚籼13号,但前二品种(系)相差不大。诱变处理的SPAD值比CK高的出现频率R259>明恢63>湘晚籼13号; M1代>M2代；抽穗期>成熟期>乳熟期>孕穗期>蜡熟期>分蘖期。诱变处理的M2、M3代,叶绿素荧光参数Fo(原始荧光量)上升,Fv/Fm明显下降,表明叶片PSⅡ受到伤害。高剂量处理使光合速率迅速降低,常规稻比杂交稻下降稍大。本研究的综合结果表明三种不同化学诱变剂的处理浓度分别以1.0%EMS、1.0X10-3mol/L NaN3、0.1%MNU的剂量效果较好；诱变后不同世代的平均总突变频率分别为：M1(8.30%)、M2(9.82%)、M3(3.36%)更多还原

【Abstract】 This research, mainly analyzed and discussed on the chemical mutagenic descendant (Mi-M3 generation) of different rice varieties (lines) respectively with the stalk of the organizational structure, agronomic traits, rice mutant, physiology biochemistry, to the photosynthetic characteristics. Especially, we systematically analysised the effects of different mutagenic chemicals on rice tissue structure and cytobiology containing vascular tissues under different treatment of different concentrations. With a view to understand the chemical mutagenesis’s mutagenic effects and mechanism on rice, to provide the basis for raising the level of rice breeding for the future. The major findings are as follows:1. The effects of chemical mutagenesis on the organizational structure in stem of the rice varieties (lines)’s different generations.To presente simply, the marrow、vascular、gas chamber are referred to "pipeline". The number of mutagenic early rice’s vascular bundles is Xiang zaoxian 33>R402>R974, for not only varieties (lines)’, but also generations’, and the number is less than that of CK; for Xiangzaoxian 33, both are M3>M2 generation; the difference was significant or very significant, In mutagenic treatment for mid-season rice Minghui 63, only a low concentration of NaN3 can lead pipe larger than that of CK treatment; for late rice Xiangwanxian 13 and R259, the pipe area increase about half comparative to CK. Only MNU、EMS、NaN3 these 3 mutagens with a high concentration, can increase the thickness of rice stem wall. In short, the mutagenic treatment make the organizational structure performance of stem degrade generally.2. Changes of mutagenic descendant for different rice varieties (lines) in flag leaf stomatal characteristics.Without mutagenic treatment, these three varieties’stomatal density is Minghui 63> R259> Xiangwanxian 13, but there was no significant difference for the former two varieties (lines). With treatment of MNU, EMS in various concentrations for Xiangwang 13, stomatal density increased to those in CK, for Minghui 63 and R259, stomatal density reduced to those in CK. 3. The effects of chemical mutagenesis on rice germination characteristics and seedling growth.In the six varieties (lines) of early rice and late rice, in addition to the effect of mutagen’s low concentration on R974, all other all treatment have a lower germination potential, germination rate than those in CK; except part of the MNU treatments, all other treatments’ germination index and vigor index were lower than those in CK; about accounting for half of the MNU treatment that the length of root and bud increased, compared with those in CK; all of EMS and MNU treatment, leaf number, leaf area, seedling height, the length of from seedling base to the heightest’s pulvinus, tiller number, seedling base width, the total root number all reduced, compared with those in CK; the each pharmaceutical treatment significantly inhibit the early and late rice’s germination rate and seedling rate. The capacity of early rice’s resistant to high concentrations is lower than late rice.4. The plant height、tiller changes in different rice varieties (lines) mutagenic offspring.After the chemical mutagenic treatment, each rice varieties(lines) average height were lower than the CK treatment and had a significant difference; The effect of induced dwarf of mutagen EMS is very obvious.The average tiller number after mutagenic treatment is basically higher than CK, especially NaN3, and EMS, in particular, the high-dose performance obvious; there is a very significant difference with CK. The tiller number and plant height in general has no significant relation.By chemical mutagenesis treatment on various species, the change process of plant height and tillers on both sides has a certain type, namely "growth-type"; early rice varieties’plant height and tiller number was S-curve of growth, the medium and late rice varieties(lines) were basically the power function equation growth.5. The effects of chemical mutagen on rice mutant.The varieties (lines) treated with chemical mutagenesis, have little difference on the occurrence rate of mutant varieties (lines) among each other generally; However, the high concentration effect>low concentration effect; M2 generation> M1 generation> M3 generation, the rate of these three generation were:dwarf strains 3.0%、3.53%、1.4%, more tillers 2.34%、3.3%、1.2%, leaf color mutant 2.49%、1.48%、0.46%, as early as ear strain 0.51%、1.59%、0.46%.The mutation rate treated from EMS slightly higher than the other two kinds of chemical mutagen’s. During different concentrations, the high-dose effect pronounced more.The dwarf mutant which are more often short plants, leaves distorted, heading-out degree difference, and many air blighted grains, weak resistance. Leaf mutant strains usually have low content of chlorophyll, cell membrane permeability is increased, electrical conductivity increased, the content of MDA increased, root activity decreased, and less accumulation of photosynthetic products.6. Different changes in physiological and biochemical characteristics of rice varieties (lines) mutagenesis future generations.The MDA、soluble sugar、SOD、POD、CAT、relative conductivity、root vigor was determined in different growth stages of late rice varieties different generations with treatment and the relevance between various indicators and root vigor. The physiological and biochemical sensitivity on different generations is M1> M2> M3; and the damaging effects of M1 generations is of the largest; in M2 and M3 generations, some indicators (soluble sugars, the relative conductivity) fall in some different levels; but each generation has weakened The sensitivity of different varieties (lines) is xiang wanxian 13>Ming 63> R259; there is no obvious differences among the different growth stages. Mutation produce some effect, such as the underground parts of rice plants has large negative effect than the aerial parts; mutagenic activity on three kinds of enzymes performance is POD>CAT>SOD. Chemical mutagenesis of rice has a longest continuing effect on the contents of MDA and soluble sugar.7. The impact of chemical mutagens on chlorophyll relative content and chlorophyll fluorescence.Whether there is mutagenic treatment or not, SPAD values are R259> Minghui 63 >Xiang wanxian 13, but the former two varieties (lines)differ less. The frequency of mutagenic treatment SPAD value higher than those of CK is R259> Minghui 63>Xiang wanxian 13; M1 generation> M2 generation; heading stage>mature stage> milk stage> booting stage>wax-ripe stage>tillering stage. In M2、M3 generation, chlorophyll fluorescence parameters Fo (the amount of the original fluorescence) rose, Fv/Fm decreased significantly, indicating that leaf PSⅡhurt. High-dose treatment reduce the photosynthetic rate rapidly, conventional rice fell slightly larger than the hybrid rice.In this study, the best concentrations for rice mutagenesis are 1.0%EMS、1.0X10-3mol/L NaN3、0.1%MNU, the mutagenesis frequency of different generations are M1(8.30%)、M2(9.82%)、M3(3.36%)。更多还原