关键词: 天目木兰, 聚类分析, RAPD

Abstract: Indigofera lenticellata is a leguminous shrub widely distributed in the dry valley of Hengduan Mountains. Its characteristics in seed dormancy and germination were studied in this paper.  I. lenticellataseeds had the characteristics of physical dormancy, and the waterimpermeability of seed coat was the main cause of difficulty to germinate. Hard seeds occupied about 85% of the total. Perforating the seed coat by a needle and scarifying the seeds by sand were the effective measures to break I. lenticellata seed dormancy. Scarification by sand for 7 h was the best treatment measure to improve the germination. The seeds germinated in a wide temperature range from 10℃ to 30 ℃, with the optimum temperature between 20 ℃ and 30 ℃. Low temperature was not beneficial to the germination. I. lenticellata had definite droughtresistant capability. Under the 25% polyethylene glycol 6000 (PEG)simulated drought stress, the seed germination rate could reach to 100%. However, drought stress decreased the germination rate, retarded the germination process, prolonged the germination cycle and preparing period, and lagged the germination peak phase. The parameters reflecting the sensitivity of I. lenticellata seed germination to drought stress were in  order of germination exponent > germination potential > germination rate. It was suggested that the optimal time for sowing I. lenticellata seeds in the field was early April, and the seeds should be scarified by sand for 7 h before sowing.

Key words: Magnolia amoena, Cluster analysis, RAPD