Study On Biological Characteristics Of Isatis Indigotica Fort.

In this paper, biological characters of Songlan(Isatis indigotica Fort.) were researched in order to offer theoretical basis for standard cultivation. The research included biological character of seed germination,morphophology and development of Isatis indigotica ,morphology and anatomy of Isatis indigotica's nutritional organ,the biological characters of reproduction and mutual effect in growing process. The main results as follows:1. The result of germination experiment shows the temperature range of Isatis indigotica seed germinating is from 10℃to 35℃;The suitable temperature of germinating is 20℃for fresh seeds, and 10℃-20℃for 2 years stale seeds. The 20℃temperature is suited for seedling growth. The germinant rate of fresh seeds is higher than the one of stale seeds and the moldy rate is lower. The water absorption process of Isatis indigotica seed includes rapid phase, slow phase and lag phase. The most rapid phase of water absorption is within 20 minutes after seed dipped, the seeds weight will be about 4.87 times as itself after 48h.2. Morphology and anatomy of leaf and root of Isatis indigotica were observed. Secondary xylem and phloem of root are clear, and there is a great lot of amyloid in parenchyma cells of cortex, phloem and xylem rays. The shape of leaf upper cuticle cells is approximately same as that of unders, and the upper and under cuticle both have stomata. The vascular bundle in nervation is clear and upgrowth, too.3. The growth trend stage on root system lag behind seedling system obviously. The root of Isatis indigotica grew rapidly in early days, the length of root was no longer changing from August to harvest time, the diameter of root was growing tardily.4. The results show that the rapid accumulation stages of store material emerge during the last ten-day period of April and the first ten days of May, the thousand seed weight reached the maximum value 7.410 g in the beginning of June. The content of reducing sugar and soluble sugar increased progressively in early days of growth, reached the maximum value 17.30 g/kg and 54.00 g/kg on April 19, then reduced rapidly after April 19, the content of amylum was increasing at the same term. The content of soluble protein was increasing in April, then reduced rapidly earlier and slowly later after May 5, which reached the maximum...