| Dendrobium stardust 'Fire bird' is a of great ornarmental value among the Dendrob-ium varieties.Such variety possesses a middle drawf plant-type,and always blooms wi-th good uniformity and light frangrance,the blooming time of which devotails with Sp-ring Festival can last two months.At present,such variety has not been introduced to the domestic market,and there are no reports about the study of its reproductive char-acterstics.Traditional ways of propagation are not able to make fast-propagation possib le and meet the growing demand of entensive market.Therefore,in order to study the reproductive characterstics of Dendrobium stardust 'Fire bird' and make the fast-propagation possible,in this study,the corolla structure and surface structure of floral organs were observed,the way of cluster buds inducing and proliferation was adopted to establish the tissuse culture and fast-propagation system,and thus to lay the foundation of studying the reproductive characteristics of Dendrobium stardust 'Fire bird' and provide theoretical support for scale production.1?In this study,we observed the corolla structure and surface structure of floral Organs,and the results were as follows:?1?The flower of Dendrobium stardust 'Fire bird' is consist of sepals,petals,lips,and gynostemium.The sepals,petals and lips are made up of tightly arranged guard cells with irregular polygon.The surfaces of sepals? cells are smooth while the surfaces of petals? cells are lightly coarse with tomenta,and there are stomatals in lips? cells.?2?Anther cap has an obverse shape,and resembles a trapezoid.The cells arrange tightly yet not smoothly,and their surfaces are coarse with gully stripes.The pollinari um is made up of two pollinia which are composed of plenty of pollenswhich arrange tightly and their shapes change as a function of maturity.The stigmas are round,and the cells are raised and variable in size.There are tomenta on stigmas for pollens landing,and the tomenta change with the development of stigmas.2?This study established the tissue culture and fast-propagation system by means of cluster buds inducing and proliferation of Dendrobium stardust 'Fire bird',and found out appropriate hormone combination in different stages.?1?When sterilized explants,using 3% mercuric chloride to treat for 6 miniutes after 5% clorox treating for 5 miniutes was the most appropriate way to effectively avoide contamination.The optimal hormone combination of lateral buds inducing were 6-BA 3mg·L-1+NAA 0.2 mg·L-1.?2?TDZ 0.1mg·L-1+NAA 0.2mg·L-1 were the optimal hormone combination in the stage of cluster buds proliferation.when added 200 g·L-1 mashed potato,the proliferati on effect was much better.In the process of tissue culture,there appeared serious browning and when added 1 g·L-1 activated carbon,the browning could be obviously limited and the cluster buds inducing and proliferation could be promoted.?3?When added 200 g·L-1 mashed potato,the effect of cultivating strong seedlinggs was favorable,and 0.5 mg·L-1 IBA could obviously promoted rooting.After hardening-seedling for 5 days,the survival rate of transplanting reached the highest.The observation of corolla structure and surface structure of floral organs laid the foundation of further study on reproductive characteristics of Dendrobium stardust 'Fire bird'.Having selected the optimal hormone combination of tissue culture in different stages and establised the tissue culture and fast-propagation system,theoretical support could be provided for large scale production.However,in the stage of cluster buds in ducing,leaves of some cluster buds developed rapidly,while proliferated slowly,such phenomenon needs further study. |
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