Application of forcing solution technology to micro and macropropagation of woody plant species.

摘要

A series of experiments was conducted to further modify the forcing solution technology in order to expedite the propagation of woody plants such as Cornus alba, Euonymus alatus, Ligustrum vulgare, Lonicera maackii and Spiraea canescens. Silver thiosulfate (STS) in the forcing solution hastened bud break, increased per cent bud break and enhanced shoot elongation. GA₃ alone or in combination with STS in the forcing solution cut time to bud break in half, exhibited a higher per cent bud break and almost tripled shoot elongation when compared to including STS alone. An average of more than 3 cm in shoot length was achieved in less than 3 weeks starting as early as December during the dormant season in the woody plant species examined. Scanning electron microscopy observations of the stems receiving different treatments suggest that the use of GA₃ and STS can mobilize stored starch to enhance the growth rate of forced woody stems. Stems from which the samples were collected apparently utilized the stored starch grains for breaking the dormant period leading to subsequent shoot elongation. Experiments resulting from addition of GA₃ + STS to the forcing solution produced more and longer shoots in vitro when compared to the STS treatment alone. Benzyladenine (BA) or thidiazuron (TDZ) added to the culture medium or the forcing solution promoted micropropagation of these woody plants. This indicated that BA or TDZ added into the forcing solution can be delivered to the softwood growth which can be then used as explants for in vitro culture. Although GA ₃ added to the forcing solution decreased rooting ability of softwood cuttings, the addition of STS following the initial use of GA₃ counteracted the undesirable effect of GA₃ on rooting. This research has demonstrated that the forcing solution technique appears to facilitate fast, effective and economical propagation of woody plants throughout the year.