Effects of harvest times on the production and quality of Bletilla striata

Bletilla striata is a perennial herb of the orchid family with its tubers frequently used in medicine, food, chemistry, and cosmetics industries. Polysaccharide, total phenolic, and militarine are the main bioactive components of B. striata that have been widely used for the treatment of hematemesis, hemoptysis, and traumatic bleeding due to the efficacy of arresting bleeding with astringent action. As the yield and quality of medicinal materials are closely related to the harvest time, it is of great significance to choose the optimal harvest time of B. striata. In the present study, effects of four different harvest times of 2-year-old B. striata were compared based on their morphological characteristics and bioactive compounds contents. The results showed that the fresh weight and drying rate of B. striata showed non-significant difference among four different harvest times. However, the content of B. striata polysaccharide (BSP) was firstly decreased and then gradually stabilized with the delaying of the harvest time. The contents of total phenolic and militarine in the B. striata harvested on Sep. 23 were the highest. Under the comprehensive consideration of B. striata quality and yield, the results indicated that it is more reasonable to harvest B. striata in late September.