The Study On Tissue Culture And Polyploid Induction Of Narcissus Tazetta L

Narcissus tazetta L. is a kind of perennial bulbous flower, belongs to Narcissus spp, Amaryllidaceae. It has big bulbs and many flowers, with early flowering and long flowering period, the flowers smell sweet and nice,it’s a high ornamental value flower. But due to the low propagation rate of narcissus bulblet,narcissus has less varieties and has a single color,so it has always been the one of key study for researchers to improve the varieties. Rapid propagation technique can produce a large number of plantlets in a short time,it also can be used for artificial seed production and the original seed preservation. Polyploid plants have such good characteristics such as strong plant, thickened scale etc.For these reasons, the studies on rapid propagation and chromosome doubling of narcissus are very important and significant both in theoretic aspect and practical aspect. Taking Zhangzhou and Huanghua Narcissus as materials, the study was carried out to develop a technological system for rapid propagation of Zhangzhou and Huanghua Narcissus in vitro,and studied the effects of different treatments on bulb formation and differentiation of callus from different parts of the narcissus systematically,so that we can screen out the suitable culture medium, and it can provide technical guidance for the rapid propagation of Zhangzhou and Huanghua Narcissus, and it also can provide the important foundation for the next step research work of transgenic breeding and genetic transformation and so on.At the same time, the study used the liquid nutrient medium and the solid medium for polyploid induction. At the same time,based on the integrated technology of tissue culture and chromosome engineering, to cultivate Zhangzhou and Huanghua Narcissus with the colchicines of two training methods in vitro, attempted to develop new methods and technology for the cultivation of polyploid germplasm, to get a higher aesthetic value of new varieties.Following are the main results.1.Using the different parts of the Narcissus flake as explants, the small bulb quality and induction rate were significantly different. The experimental results showed that the best medium was MS+0.2mg/L 6-BA+0.5mg/L 2,4-D+0.1mg/L KT for the outer bulblets of Zhangzhou narcissus,a the best medium was MS+0.5mg/L 2,4-D+O.lmg/L KT for the middle bulblets of Zhangzhou narcissus.and the best medium was MS+0.5mg/L 6-BA+1.0mg/L 2,4-D+0.1mg/L KT for the outer bulblets of Huanghua Narcissus, the best medium was MS+ 0.5mg/L 6-BA+0.5mg/L 2,4-D+0.1mg/L KT for the middle bulblets of Huanghua Narcissus.2.This study was compared with narcissus bulb outer and middle found that, the effects were not good when used the bulb outer of Zhangzhou and Huanghua Narcissus, it is probably because the bulb outers are browning easier, this may be affect the induction of the callus of stem and bulb. Because of the high toxicity of mercuric chloride, so that we should keep the browning rate low, and also ensure the induction rate higher, so we should choose the bulb middle of Zhangzhou and Huanghua Narcissus.3.On the basis of tissue culture,by use the liquid nutrient medium and the solid medium for polyploid on Zhangzhou and Huanghua Narcissus,we compared with the mutagenic effects and found that this two methods are able to induce polyploid plants, but the induction rate and mortality are higher when use the direct liquid method.4.Using different pretreatment methods for the Huanghua Narcissus,we found that, the colchicine,8-hydroxyquinoline,1,4-dichlorobenzene have the effect on the metaphase chromosomes,but the effect of ice on the chromosome condensation and dispersion is not good; the chromosome morphology and dispersion are good, constriction region is relatively clear when the colchicine concentration of 0.02% treat 8 hours; the chromosome morphology and dispersion are good, constriction region is very clear when 8- hydroxyquinoline treat 8 hours;the dispersion is good,but the chromosome morphology is not very well when the santochlor treat 8 hours,so we choose the 8-hydroxyquinoline and treat 8 hours.5.From the results we can be seen,Zhangzhou and Huanghua Narcissus treated by colchicine,the bulblet are bigger than no treat,the stoma is also obviously turn larger,the number of stomata per unit area are significantly reduced. We didn’t find Six diploid in Zhangzhou Narcissus,but we found the tetraploid plants in Huanghua Narcissus. At the same time, we found the aneuploidy on the two kinds of Narcissus.