微孔草种子萌发特性的研究

Studies on the Germination Performance of Microula sikkimensis Seeds

本文探讨温度、预冷处理以及逆境条件对微孔草种子萌发及生长的影响。结果表明：微孔草种子具有12个月左右的后熟期，自然贮藏后再经预冷处理方能完成后熟破除休眠。在相同温度（20℃）下，贮藏12个月后的种子（1996年收）发芽率比收获当时高41％，在15／25℃条件下预冷处理后发芽率可达72％。其萌发最适温度及预处理在预冷（5℃，5天）和20℃恒温或15／25℃变温条件下，1994、1995年种子的平均发芽势分别为61％和71％、发芽率分别为72％和79％、苗长（4．6mm和4．6mm）及活力指数（169.0和175．6）皆显著高于其它处理（P＜0．01）。发芽试验初次和本次计数时间分别以第4天和第8天为宜。微孔草种子较耐高温，不耐盐碱。与1994年的种子相比，1995年的种子抗逆性较强，各项指标下降幅度小，且在老化试验中发芽指数及活力指数与对照间无显著差异。在人工栽培条件下1995和1996年收获种子的千粒重极显著高于野生（1994年采集）种子，平均千粒重为1.515g。

The obective of thes work was to investigate the effects of temperature, prechilling treat-ments and stress condition on seed gemination and growth performance of Microula sikkimensis(Clerke)Hemsl. The 1000-seed weight was also studied. The results showed that M. sikkimensis seeds had a neary12 months for after-ripening period, the seeds became maturity after storage and the prechilling treatmentcould break down the seed dormancy. At the same temperatre(20℃), the percentage germination of theseed which was harvested in 1996 and had been stored for 9 months which germination increased by 36%as compared with the new harvested seeds. The prechilling treatment was the best for the seeds being at5℃ for 5 days, the optimum gemination temperature was constant temperature at 20℃ or alternative at15/25℃. By these two treatments, the germination performance of the seed sample from 1994 and 1995,such as the mean germination speed (4 days,61 %,71 % ), the percentage germination(72%,79% ), theseedling length (4. 6mm, 4. 6mm) and vignur index (169. 0, 175. 6), were significantly improved as com-pared with other treatments(P < 0. 01). A good time for the first and the final seedling counting are at 4thday and 8th day, respectively. M. sikkimensis seeds had a relatively strong high-temperature endurance.They were ealt sensitive. Particularly, the seeds of 1995 showed the stronger stress resistance, it is germi-nation speed and vigour index were higher than those seeds of 1994. And the aging test showed no differ-ent with the control.The 1000-seed weight of the cultivated seeds(harvested in 1995 and 1996) was sig-nificantly different with the seeds of wild plants (1994), the 1000-seed weight were 1 .515g.