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Lagerstroemia Lythraceae Lagerstroemia is the important concept of summer flowering shrubs or small trees, because of its rich colors, long flowering period, stem, root unique, highly ornamental value and adaptability in landscaping and plant landscaping play an important role. Crape myrtle as a fine species landscaping worthy of further study to be better utilized. This test uses the the colchicine seedlings drip method, different concentrations of colchicine, the mutagenic effect of different processing time three crape myrtle. Morphological indicators observation of treatment plants, and mutants were identified as cytology and flow cytometry, successfully induced crape myrtle tetraploid material, and further compare the differences of tetraploid and diploid tetraploid material through outdoor the cuttings and indoor group training propagation save. The test results are as follows: 1. Colchicine induced three crape myrtle varieties are tetraploid plants, 0.2% -0.8% concentration of processing to produce different degrees of morphological variation in the processing time of 48h-96h. Orthogonal test showed that: silver Wei Hongwei handle the high mutation rate of 48h-96h, colchicine concentration of 0.5% -0.8% 0.5% colchicine treatment factors tested processing Hongwei 72h mutation rate is highest , amounted to 54.17%. Colchicine produce different degrees of inhibition on the growth of crape myrtle, the performance of true leaf stage delay, reduced leaf number, leaf width, growth slows down, low flowering and fruiting. 2. Morphological identification of mutants compared with the control, the blades are long, wide, thick on average, respectively, increases of 24.7%, 46.0%, 127.5%, leaf index decreases, dark green leaves, leaf texture is rough; cytological studies have shown that variations the strains stomatal guard cell length, width average increase of 49%, 31%, stomatal density decreases, approximately 44.3% of the contrast, 62% increase in the number of chloroplasts in the guard cells, pollen grain diameter increased 32%; initially explored suitable Lagerstroemia Chromosome tablet technology, diploid chromosome number: 2n = 2x = 48 tetraploid chromosome number: 2n = 4x = 96; flow cytometry identified 15 tetraploid plants, chimeras 13 strains. 3. Tetraploid and diploid in phenology, flower morphology, pollen viability, pest resistance, etc. have differences. Crape myrtle tetraploid than diploid addition to sprout leaf expansion a few days earlier than those of other phenophases diploid delay flowering stage than diploid about a month later, to some extent, delayed flowering. Tetraploid flower diameter, petal length, petal base claw long compared with diploid increase, the average increase of 21.0%, 38.8%, 53.5%, greatly improving the single-flowered ornamental value. Sucrose, boric acid medium, and I 2 -KI the TTC staining 0.5% are not satisfactory determination of the crape myrtle pollen viability, pollen viability determination of suitable medium for ME 3 the 16 PEG 4000 12% sucrose, lower by the determination of crape myrtle tetraploid pollen viability, pollen germination rate of 44.4% of the diploid. The field pest survey showed that tetraploid crape myrtle resistance to powdery mildew and pest resistance capacity than those of diploid improve. 4. Than diploid to tetraploid since outcrossing rate is low, only 26.7%. From selfed offspring seedling extract eight typical morphological mutants identified by flow cytometry are tetraploid. 5. Outdoor cuttings as well as indoor tissue culture propagation and preservation of tetraploid plants. Tetraploid outdoor cutting survival rate than diploid slightly lower, but the difference was not significant. Indoor culture explants disinfection time than diploid, the appropriate diploid initial medium (MS NAA0.05mg / L BA1.0mg / L), and the proliferation medium (MS NAA 0.05mg / L of BA2 benthic assemblage. 0mg / L) is not suitable for the cultivation of tetraploid. Although tetraploid Outdoor cuttings and indoor group training than in the diploid difficult, but vegetative propagation as a way to save by crape myrtle tetraploid its feasibility, should further improve the methods.
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