| Yields and agronomic characters based on the field experiment, the contents ofpolysaccharides and alcohol-soluble extracts of13F1families of Dendrobium officinale, as well asthe special culture mediums for the superior families and clones were studied in this paper. Theresults were showed as follows:1. The differences in yields and agronomic traits among F1families of D. officinale weresignificant. The fresh and dry weight of the overground parts were362.4~1993.0g/m2and76.4~238.2g/m2, respectively, while the fresh and dry weight of stems were202.1~1168.7g/m2and51.2~136.0g/m2. The hybrid vigour was obvious. Plant height, stem diameter, leaf number,blade length and blade width were all significantly correlated with biological yields and economicyields, and among which, stem diameter, leaf number and blade length were the most significant.The number of shoots that fewer than4.5could affect yields of families. Shoots number, stemdiameter and leaf index were basic stability when compared biennal traits to annual, which couldbe used for early selection.2. The differences in the contents of polysaccharides and alcohol-soluble extracts among F1families of D. officinale were significant. The polysaccharides contents collected in May andFebruary were32.89~43.07%and25.77~35.25%, respectively, while the extracts contents were2.81~4.85%and7.90~17.40%. Harvest time would significantly affect the contents ofpolysaccharides and alcohol-soluble extracts. The extents of quantitive variation ofpolysaccharides and alcohol-soluble extracts were different among families.3. According to the results of yields, agronomic traits, polysaccharides and extracts contents,3superior families (6×2,9×66and78×69) were selected. Among them, the stem fresh and dryweight of6×2family could reach1168.7g/m2and136.0g/m2, respectively, which were higherthan CK173.4%and39.1%. And the contents of polysaccharides and alcohol-soluble extractscould reach43.07%and17.40%. Besides, it was suitable for fresh-eating with the advantage ofsturdy stem and superior mastication.9×66and78×69families both had high yields, and the stemfresh weight were712.9g/m2and689.5g/m2, which were higher than CK66.8%and61.3%,while the stem dry weight were128.2g/m2and122.4g/m2, which were higher than CK31.1%and25.2%. The polysaccharides contents of these two families could reach39.36%and40.52%, respectively, while alcohol-soluble extracts contents could reach7.90%and10.23%. The stems of9×66and78×69families were dark purple, moderate thickness, and fragrant and sweet for fresh.9×66and78×69were suitable for dual purpose of fresh-eating and processing. In addition, theywere suitable for original ecological culture because of their good ability to resist low temperature.4. The explants were obtained from stem segments of hybrid combination of D. officinalegermplasms (Zhejiang Yandang Mountain×Yunnan Guangnan). The screened culture mediums forbuds induction and multiplication, which were1/2MS+IBA1.0mg/L+6-BA1.0mg/L and1/2MS+IBA1.5mg/L+6-BA0.5mg/L respectively, were applied to159germplasms of D. officinale.The medium for axillary buds induction had universality with94.3%induction rate. During budsmultiplication, three proliferation forms i.e. single bud, multiple buds and protocorm weredifferentiated from different germplasms. The results showed that different germplasms of D.officinale had specific requirements for culture medium. Therefore, developing special culturemedium for breeding clones of D. officinale has urgency and important application values. |
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