Study On Seed Germination And Seedling Emergence Characteristics Of Platycodon Grandiflorum Seed

The different maturity degree of Platycodon grandiflorum seeds which collected in different periods by making the labels as the material and then germination rate was determined, the germination rate and germination vigor were also determined in different storage under room temperature and-20℃in the fridge. The ability of emergency and sowing depth of which relationships with agronomic characters of Platycodon grandiflorum seed between the laboratory and field were also determined which could provide the basis for the production, conservation and sowing method of Platycodon grandiflorum seed.The results showed that the relationships between the maturity degree and seeds dormancy of platycodon grandiflorum seeds, different maturity stages of germination rates were measured, good mature seed, germination rate at or close to 80% in mid-October, poor maturity seed, germination rate at or close to 80% in February the next year. Therefore, seed maturity has great influence on the seed dormancy period of platycodon grandiflorum seed, good seed maturity have a very short period of dormancy, poor maturity seed have longer dormant period.The germination rate and germination vigor were also determined in different storage under room temperature and-20℃in the fridge. The results showed that: storage temperature has great impact on germination vigor and germination rate, germination vigor and germination rate declined after store 20 months and 22 months respectively in room temperature storage conditions, platycodon grandiflorum seed had completely lost their germination ability when stored 48 months. However, germination vigor and germination rate maintained high level in four years in-20℃storage conditions, all more then 80%.Effects of covering material, covering thickness and temperature on emergence process and the days of emergence of platycodon grandiflorum seed. The results showed that:under the temperature of 20℃the emergence of platycodon grandiflorum seed at earliest in 10 days, and at latest in 19 days, however emergence of seedling completely dead at the beaker in the 30 days Under the conditions of 15℃, platycodon grandiflorum seeds come up from the soil at earliest in the 15 days, at latest in the 34 days, in the 42 days emergence of seedling completely dead at the beaker.Effects of depth of planting on emergence and growth of platycodon grandiflorum seed the results showed that:The highest emergence rate was in the 3cm sowing depths, about 92.5%. Overall merit, main agronomic characters of platycodon grandifldrum was best in growth mid-term and harvest best in the 3cm sowing depths.