Solomon's seal (Polygonatum odoratum) seedlings raised through its seeds can replace the rhizomes impelling higher cost for transplanting, This experiment was done to determine the seed characteristics and the germinating processes to give some information on bulk production of seedlings using the seeds. The external or internal morphology of seeds or seedlings grown in lab. or greenhouse was examined mainly with stereomicroscope. The external shape of Solomon's seal seed was hard seed-coat and orthotropous ovule with linear type embryo stretching to the center of seed. Germination proceeded through the several steps. The lower part of seed embryo having the primordia of bulbil and roots first grew before the bulbil and roots was developed from the primordia. The lower part of embryo was enlarged toward the endosperm of seed as soon as seed germinated. Then epicotyl was formed on the apex of bulbil. The epicotyl was elongated after at least 6-week chilling treatment for breaking its dormancy and the first leaf shape was affected by light intensity given during seedling emergence. The bulbil was the first organ of the rhizome used as tea or herb medicine.
Solomon's seal (Polygonatum odoratum) was traditionally propagated by its rhizomes but seed propagation has not been practiced due to their dormancy and high price. To improve the seedling production through seed pretreatments, the experiment was conducted to determine the effect of seedcoat softening and seed prechilling on seed germination and bulbil formation of the seal. The prechilling was done for 4 to 16 weeks at and the softening was forced with 10% KOH for 40 minutes. Seed germination, bulbil formation and length, no. of root and root length were measured at 6 and 12 weeks after sowing. Seed germination and bulbil formation were greater at 8 to 12 week prechilling than at shorter or longer treatment when only the prechilling was enforced. Prechilling had greater effect compared to seed coat softening. In addition, the softening treatment before prechilling showed higher germination and bulbil formation compared to single treatment of them. The softening treatment prior to prechilling was better than the reverse treatment in number of root except the above two characters. Duration of prechilling treatment was able to be shortened below 8 weeks when the softening treatment was applied before prechilling.
Seed-propagation of Solomon's seal (Polygonatum odoratum) takes 2 years to shorten the period for becoming a practical method. The experiment was done to establish a proper method of breaking the epicotyl dormancy in bulk seed-propagation. Seedlings with a bulbil were treated with every 2 days for 4 or 8 days and chilling treatments at were enforced for 4, 6, 8 or 12 weeks. Emergence- and growth-related characteristics were examined immediately after the treatments, 3 and 6 weeks later. Rate of cotyledonary sheath rupture immediately after treatment was greater in its 8-day treatment than in 4-day although its effect disappeared later. However, any epicotyl treated with solution did not elongate so that new seedlings disemerged over the bed soil. That resulted from not breaking the epicotyl dormancy since did not rupture all of the cotyledonary sheath formed with several sheets and consequently, the solution did not reach it. The treatment for bulk seed-propagation, therefore, was impractical method. On the contrary, the chilling treatment was able to be applied to the seed-propagation because of getting the cotyledonary sheath rupture and the epicotyl elongation. Seedling emergence and its growth after chilling treatment were influenced by chilling period although required at least over 6-week treatment for satisfactory results.
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