The Effect Of Chemistry Mutagens On The Organizational Structure And Agronomic Traits And Physiological Characteristics In Rice Offspring

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%)。...