Rapid Propagation And Tetraploid Breeding Of Zamioculcas Zamiifolia Rehd.

Zamioculcas zamiifolia Rehd.,a member of the family Araceae,as an indoor foliage plant with unique ornamental value was developed in recent years in the world.Plant tissue culture and colchicines induction technology were applied to the induction of tetraploid of optimal improved variety with Zamioculcas zamiifolia Rehd.,and systematically researched on rapid identification, multiplication,the rooting and transplanting of test tube seedling.The explants were dipped in the scour 10 minutes and washen,then sterilized 20 seconds by 75%alcohol and 10min by 0.1%HgCl₂,rinsed 4～5 times by sterilized water.The young leaf is the best explant for inducting callus.The appropriate medium for inducting callus from explants was MS+ 3.0 mg/L6-BA+0.2 mg/LNAA,induction rate was 88.9%.When MS+3.0 mg/L 6-BA+0.1 mg/LNAA was used as multiplication medium,differentiation rate and multiplication rate were the highest,315%and 4.2 respectively.The best rooting medium was 1/2MS+0.5 mg/L IBA,the induction rate was 98.9%,the states of plantlets and roots were good.The surviving rate of plantlets was above 95.0%after transplanted to the ground.The ploidy of plantlets identified and the numbers of chromosome were 34(2n=2x=34).Under the condition of tissue culture,the inducing tetraploid of Zamioculcas zamiifolia Rehd.was carried out by colchicine.The tetraploid plantlets were obtained by immersing buds in various concentrations of colchicine solution,the result showed that,It was the most effectively induced by immersing buds in 0.4%colchicine solution for 24 hours,which had the most tetraploid plantlets, the inductive frequency was 10%.Tetraploid plants and a few chimeras were obtained by colchicine inducing.Tetraploid Zamioculcas zamiifolia Rehd.had a good multiplication and rooting effect,which cultivated on the best mediums for diploid plant.Tetraploid plantlets of Zamioculcas zamiifolia Rehd.were transplanted and survived transitorily.The tetraploid and the diploid were observed from the external morphology and cytology.It was showed that in the same stage of growth and environmental conditions,the tremendous sexual organs were reflected by tetraploid plants under the leaves.The blade's thickness and width were both greater than the diploids,whose length was 186%than that of the diploids,and the width was 123%.But the shaped index was smaller,only 66.7%of the diploids.The tetraploid plants were growing more vigorous than the diploid with trunk sturdy and mast root.On the comparison of stomatal characteristics,the defending cell of the tetraploid increased significantly,whose diameter was about 127.2%than that of the diploid,longitudinal diameter was about 123.4%.The number of chloroplasts in the guard cell was noticeably increased,which was about 151.0%than the diploid.Anyways,the stomtal density of the tetraploid was decreased approximately 67.2%of the diploid.The tetraploid plantlets and diploid plantlets of Zamioculcas zamiifolia Rehd.were carried out the low-temperature treatment,then their exosmosis rates of electrolyte and catalase activities were compared.Under the same temperature,the electrolyte exosmosis rate of Zamioculcas zamiifolia Rehd.plants were lower than diploid plants.Especially,when in 0℃condition(under Zamioculcas zamiifolia Rehd.'s lethal low temperature),electrolyte exosmosis rates of diploid of Zamioculcas zamiifolia Rehd.was 93.63%,but its tetraploid's electrolyte exosmosis rates was 82.31%.The catalase activities of tetraploid of Zamioculcas zamiifolia Rehd.was higher.These results show that the tetraploid Zamioculcas zamiifolia Rehd.'s cold resistance is stronger than diploid Zamioculcas zamiifolia Rehd..The chlorophyll content was closely related to the photosynthesis,the mensurate result find that,it was increasing along with the ploidy.This result can provide important data for planting and breeds selectively.