[Study on seed dormancy mechanisms of Changium smyrnioides and its geminating conditions].

ABSTRACT

OBJECTIVE: To study the seed dormancy mechanisms and the optimal seed germinating conditions, so as to provide basis for the seed testing of Changium smyrnioides. METHOD: Put the seeds into wettish sand under temperature of 25, 20, 15, 10, 5 degrees C, observe the shape changing of embryo and measure its length every other 10 days. Carry on experiments of seed germination under temperature of 25,20, 15, 10, 5 degrees C on the paper bed and sand bed, determine the time of germination starting, time of germination lasting, germination rate and germination energy. RESULT: Embryo grew the most quickly under 15 degrees C. The seed germination was largely prohibited when the temperature is higher than 20 degrees C. The mildew rate was very high under 25, 20, 15, 10 degrees C. Put the seeds under 5 degrees C for 45 days could quickly break off its dormancy, and its mildew rate was lower. The seeds germinate fastest under the condition of 15-10 degrees C on the paper bed, and its germination rate was the highest. CONCLUSION: The morphological post-maturation seems the major dormancy mechanism of C. smyrnioides. Temperature is a major factor that affect seed germination of C. smymioides. The best pretreatment method is to put the seeds into 5 degrees C of wettish sand for 45 days. The best germination bed is the paper bed, and the best germination temperature is 15-10 degrees C.