天麻在贵州的生长发育周期，经试验由一般3～4个整年缩短为2个整年。

Gastrodia elata is a plant belonging to orehidaceae family whose root and are degenerated without the ability to carry out photo synthesis,but can growrmillaria Armellea by symbiosis.Its cy-cle of growth and development from seeds to seeds is much changable under artifieial control.Our previous experience on the sexual propagation of the plant in Guizhou showed that two to four years are needed for its growth and development.It is now found that the cycle can be shortened to two years in the greenhouse partly through breeding and artificial pollination for mature fruit and plumpy seeds and partly through reasonable designing and sowing half a month inadvance.So G.elata can be available on the market one or two years ear-lier.