暗期中斷 處理時間에 따른 바위솔의 生長과 開花

Orostachys japonicus, called Wasong in herb medicine, has been artificially cultivated as an anti-tumor medicinal. The experiment was done to examine the effect of night-break periods imposed immediately before its bolting time on its morphological, flowering-related characters and fraction dry weights. After a plant was grown in a 15cm plastic pot containing a 2:1 soil: Peat moss mixture for about 3 months, three different night-break periods (0.5, 1 and 2 hours) around midnight were treated from Aug. 24. to compare with the natural daylength. The plants were sampled 6 times by 2-week interval after the treatments. Plant height and inflorescence length of all the treatments inclined with time lapse after the treatment and were shorter in 2 hour night-break due to slow increment than in the other treatments, while stem diameter showed reverse result. All the treatments except 2 hour night-break were nearly same in fraction, shoot and total dry weights per plant: two hour night-break treatment had greater leaf and bract weight from 6 weeks, greater stem, shoot and total weights from 2 weeks and greater root weight from 4 weeks but did less floret weight after the treatment. Although florets on the inflorescence were formed in 2 hour night-break treatment, flowering florets and flowering plants never occurred. In the other treatments showed the similar response, however, more florets appeared from 2 weeks, flowering florets was sharply increased from 6 weeks and flowering plants were reached up to 100% from 6 to 8 weeks after the treatment. Inflorescence length or number of total florets per plant in 2 hour night-break was positive-correlated to all the fraction dry weights except that those of natural daylength was not done, meaning that its artificial cultivation should permit bolting to secure more shoot dry matter.