Studies On Seed Dormancy Mechanism And Releasing Strategies Of Lavandula Angustifolia Mill

Mechanism of seed dormancy and the releasing strategies are studied for Lavandula angustifolia Mill. which is cultivated in Netherland and Yili in Xinjiang, China. The observation on morphological and biological characteristics have conducted on the seeds. The seed dormancy has been break down by cold stratification or hormone treatment. It has been researched that the reason of seed dormancy and growth inhibiting of seed coat by testing the germination inhibitor in the different parts of seeds, culturing embryo and determination the changes of hormone content in these tissues of seeds after the seeds collection till their germination. Then the first problem of seed propagation has been solved. After that it has been tried to discuss about the relationship between the characters of seed dormancy and germination of Lavandula angustifolia Mill. The result showed as follows:1. Lavandula angustifolia Mill seeds have fine quality, high vitality and with the hard testa which without any obstacle for water absorbing.2. By the comparison of seed vitality and germination experiment: The seed vitality is significantly higher than the germination rate in the two species. The seed vitality of seed from Holland and Yili is 95% and 82.5% respectively; and the seedling rate is 18.7% and 5.3% respectively. It indicates that the seeds of the two species are dormant.3. By the embryo culture, it has been indicated that the seeds embryo can't germinate with testa. After removed it, the two species of lavender's germination rate could getting to 100%. It is proved that embryos of the two species didn't exhibit the character of dormancy. It has been known that testa is the key points for the dormancy of lavender.4. the germination inhibitor test data show that there is inhibitor of Chinese cabbage seeds in the extract solutions of lavender embryos and seed coats from two planting districts both Netherland and China Yili . There is more inhibitor in seed coats than embryos of lavender. The seed coat inhibitor made the principal factor of seed dormancy excluding the embro dormancy because of germination of lavender embryo in vitro culture.5. the lavender seed stratification test data show that the stratification of the lavender seeds at 4℃can effectively break down the seed dormancy and the lavender seed germination rate from Holland can reach 76.7% ,the germination rate 58% fromYili . There is no positive connection between the inhibitor content in the seed coat and lavender seed dormancy.6. the exogenous hormone test shows that gibberellins can significantly effect the lavender seed germination rate. The effect of GA3 decreases with the increasing concentration and the treating time. The optimum concentration and treating time to break down the lavender seed dormancy is 300 mg/L GA3 and 6 hours soak time for the lavender seeds.