The Obtention And Preservation Of Zinnia Elegans Tetraploid Induced By Colchicine

Zinnia(Zinnia elegans Jacq.)as a good flower beds and flower border plant, hasexcellent ornamental value. This test induce polyploid Zinnia elegans by colchicinedealing with seedling stem tip growth point method. Through morphology observationwas carried out on the plant, cytology identification and determination of flow cytometryinstrument filter, obtain tetraploid Zinnia elegans. Finally, the tetraploid self-bredprogenies were identified, selection and preservation. The main results followed:1.The results of orthogonal experimental design. Design of colchicine concentration,treatment time and inbred line three factors three levels, deal with inbred lines J9, J 10(12)and A5(12) seedings. The results show that three factors on the seedlings mutationsequence is inbred lines> colchicine concentration> time. The morphologic variation rateof J9 and A5 (12) is higher, respectively 68.7% and 71.1%. When the colchicineconcentration is 0.15%, the morphologic variation rate is the highest, reaching to 72.9%.When the inbred line J9 was treated by the colchicine whose concentration is 0.15%for56h, the seedings morphologic variation rate is higher and the lethality rate is moderate,respectively 76.6% and 46.0%. By morphological observation, cytological identificationand determination of flow cytometry,three inbred lines all obtained tetraploid. Comparedwith their Corresponding diploid, tetraploid have lower plant type, thickset stem,pachyntic leaf, shorter pedicels, larger flower, longer stomata, bigger pollen grain andseed.2.The results of single factor design. Dealed four different inbred lines seedlings A5(14),J6, J10(14)and A3 with 0.15% colchicine for 56 hours. The results show that four inbredlines seedings lethality rate and morphological variation rate were the most significantdifference. The lethality rate of A5(14) is lowest and the morphological variation rate ishighest, reaching to 66.5%. However the inbred lines A3 has the highest morphologicaland the lowest variation rate which is only 32.9%. Four different inbred lines ofmorphological variation plants in through further cytological identification anddetermination of flow cytometry, finally all selected out tetraploid plants.3.Tetraploid inbred preservation. In the orthogonal experimental, because of the hig her temperature and lower pollen viability in the summer, only the tetraploid plant A5(12)-7 set seeds, harvesting one seed. After sowing and seedling emergence, th e seedling growth potential is weak, soon died. In the single factor experiment, tet raploid plants A5(14)-2-10 and J13-1 set seeds, respectively harvests 5 seeds and 7 seeds. After sowing of the selfing first generation(S1), plantlets including A5(14)-2-10-1, A5(14)-2-10-2, J13-1-1 and J13-1-2 were found in the morphology and cy tology aspects to show similar characteristics to female parent tetraploid, showing stronger plantlet, low compact plant type, larger thicker leaf, deeper color, more s parse blade back reticular veins, bigger flower diameter, larger stomata, smaller sto mata density, more chloroplasts in guard cell,Larger seeds and so on. And further proves the tetraploid progeny plants as well as for tetraploid. After self pollinatio n, tetraploid inbred S1 plants A5(14)-2-10-1, A5(14)-2-10-2 and J13-1-2 respectivel y harvest 20、11 and 10 seeds, while J13-1-1 is not fruiting. Through the morphol ogical observation of tetraploid inbred S2 plants, there are obvious differences bet ween tetraploid inbred S2 and diploid plants, and tetraploid inbred S2 Still keep t he good characters of maternal tetraploid. Through comprehensive comparative anal ysis of maternal tetraploid (SO), tetraploid inbred S1 and tetraploid inbred S2 plant s, then surely the research of the obtention and preservation for the tetraploid is s uccessful.