[Seed dormancy mechanisms of Pseudostellaria heterophylla and its germination characteristics]

Seed dormancy mechanisms, breaking dormancy and the optimal germinating conditions were studied to improve reproductive efficiency and quality standard of Pseudostellaria heterophylla.

The P. heterophylla seeds were stratified into wettish sand for 65 days under the temperature of -2-3 degrees C, embryo length and germination dynamic change of seeds were measured in prophase every other 10 days and in middle every other 5 days. The influences on seed germination and seedling growth under different temperatures, germination beds were investigated.

The P. heterophylla seeds embryo morphology was unchanged in stratification. The seeds could not germinate at stratification within the first 35 days. The germination rate and germination energy of seeds increased with the stratification time after 35 days. Germination rate, germination energy, plant height and fresh weight under the 10 degrees C were significantly higher than those under other temperatures. Germination rate, germination energy, plant height, fresh weight and dry weight of plant in sand bed were higher than those of plant in other beds, and seed mildew rate and abnormal seedling proportion of plant in sand bed were less than those of plant in other beds.

The dormancy of P. heterophylla seeds is mainly the physiological post-maturation. The optimal germination conditions of seeds is 10 degrees C the culture of sand. The dormancy was broke under -2-3 degrees C of wettish sand for 45-50 days in practice.