Research On Polyploid Induction By Colchicine In Zamioculcas Zamiifolia Engl.

Zamioculcas zamiifolia Engl., belongs to the Zamioculcas HW.Schott of the Araceae family that is an evergreen herbaceous perennial plant originate from eastern Africa. The Z. zamiifolia is a shade and drought tolerant plants with grow under low light conditions. As its unique appearance, low maintenance requirements and limited pest problems are characteristics that contribute significantly to its ornamental and interior plant. Polyploid breeding of Z. zamiifolia will be helpful to create new varieties and improve the ornamental quality to advance more quickly. In this study, the method of colchicine induced chromosome doubling of Z. zamiifolia was researched and the homozygous autotetraploid plantlets through chromosome identification were obtained. The experiment also compared the difference in appearance, stomata, the leaf cross-section, the content of chlorophyll, the activity of POD and CAT of different ploidy Z. zamiifolia.The results are as follows:1. The effects of different concentrations and processing-time of colchicine was studied at different stages in Vitro and Vivo of Z. zamiifolia. The results showed that:in Vitro, dipping the young leaf in0.1%colchicine solution for24h lead to a variant rate of plants13.3%, but there was not got tetraploid plantlets; dipping the buds in0.2%colchicine solution for48h, the rates of variant plantlets and tetraploid plants were23.3%and6.7%; in Vivo, dipping the buds in0.1%colchicine solution for48h was gained the high frequency induction which the rates of variant plants and tetraploid plants were25%and15%; immersing tuber buds with0.1%colchicine solutions for6d was the best result which the rates of variant plants and tetraploid plantlets were12.5%and5%respectively. All of above, the most tetraploid plantlets obtained by immersing buds with0.1%concentration colchicine solution for48h in Vivo.2. The result showed that the nuclear DNA content in the cells of the homozygous autotetraploid plants was twice of that in diploid plants by flow cytometry determination. It is good method by using flow cytometry to identify ploidy of Z zamiifolia was simpler, rapid and accurate.3. The tetraploid plantlets grew slower than the diploid plants. And leaves of tetraploid had thicker rachis, thicker leaf, smaller leaf index, larger guard cells, less stomata per unit area, larger epidermal cells of leaves, broader palisade tissue and the sponge tissue than the leaves of diploid. The increase of chlorophyll content in the leaves was significant with the chromosome doubling. And the activity of POD and CAT also increased significantly along with the chromosome doubling.