Progress on research of tissue culture of Bletilla striata

Rhizoma Bletillae is in high demand as a traditional Chinese medicine, and the natural resources have been severely damaged due to excessive exploitation. Because Bletilla striata seeds are small and have no endosperm, the seed germination rate is low in natural conditions. Traditional division propagation could not meet the demands of large-scale cultivation. Tissue culture can provide many seedlings in a short time and is more effective and convenient than other methods. Most studies on tissue culture of B. striata selected seeds as explants. This review summarized the processes of the aseptic seed germination pathway. It included such stages as seed germination, proliferation of clusters of buds, induction of root- ing and transplanting of seedlings. Influential factors as well as optimum combination and concentration of the plant growth regulators of each stage were also summarized. The further research on tissue culture of B. striata was also prospected.