Objective: To provide theoretical basis for artificial cross breeding of Scutellaria baicalensis by studying the characteristics of stigma receptivity as well as the viability and life-span of pollen. Method: The pollen viability of S. baicalensis was measured by 2

3

5-triphenyltetrazolium chloride (TTC) and iodine-potassium iodide (I2-KI) tests

and the pollen viability under different storage methods

temperatures and duration were detected by I2-KI test. Furthermore

the stigma receptivity was detected by benzidine-H2O2 method. Result: TTC and I2-KI showed the same effectiveness in the detection of pollen viability. The pollen viability of S. baicalensis demonstrated increase first and then decrease with the increase of blooming time. The highest pollen viability was at day 4 after blooming. Among 8:00 to 18:00

pollen viability was over 62%; and at about 12:00

pollen viability was highest (86.58%). The pollen viability was decreased with the extension of storage time

with difference between different storage methods (dry method and wet method). The growth rate of stigma tended to be stable at day 5 after blooming

and the stigma receptivity was strongest at day 6. Conclusion: The best time of artificial pollination of S. baicalensis is day 5-7 after blooming

and the pollen at day 4 after blooming could be used to pollinate the stigma at day 5-7 after blooming.