Seed Germination and Seedling Growth and Development Characteristics of llicicum difengpi, an Endemic Plant of Karst Region

In this paper, seed germination and seedling growth characteristics of llicicum difengpi were studied by observation experiments. The results showed that the seeds of I. difengpi began to germinate in the middle of March when the temperature was about 20 ℃ with the germination characteristics of high germinati germination potential and germination index and long average germination day. The cotyledon period of I. difengpi seedlings was about 2 months, and then the shoot sprouted once every 2 months or so, and sprouted three times a year. In additon, I. difengpi seedlings were suitable for growth at temperatures above 20 ℃, and seedlings grow slowly when the temperature was 10—20 ℃ and almost stop growing when the temperature was below 10 ℃. In annual I. difengpi seedlings, the length of the underground part was greater than the height of the aboveground part, while the dry weight of the aboveground part was greater than that of the underground part. The ratio of root to shoot was 1∶7. The seedlings had high chlorophyll content, low chlorophyll a/b value, and had certain tolerance negative. According to the growth characteristics of I. difengpi seedlings, water and fertilizer management should be strengthened to promote the coordinated growth of aboveground and underground parts of I. difengpi seedlings, and the survival rate of seedlings could be simultaneously improved by proper shading.