光照对不同海拔的南川绣线菊和锥花小檗种子萌发的影响

Effects of different light conditions on seed germination of Spiraea rosthornii and Berberis aggregata at different altitudes

对青藏高原东缘不同海拔的南川绣线菊(海拔2500、2700、3020和3300 m)和锥花小檗种子(海拔2160、2760、3000和3250 m)在12 h光周期和24 h全黑暗条件下的萌发进行了研究。结果表明:(1)南川绣线菊的种子大小与海拔之间呈显著负相关,锥花小檗的种子大小与海拔无显著相关性。(2)南川绣线菊种子,除有光条件下种子的萌发率与海拔有较弱正相关外,光下萌发速率、暗处萌发速率、暗处萌发率均与海拔有显著的正相关;锥花小檗种子在光、暗培养条件下的萌发率、萌发速率与海拔之间均没有相关性,但不同海拔种子的萌发率、萌发速率有显著差异,2760 m采集的种子萌发能力最高,随海拔降低或升高,萌发能力降低。(3)不同海拔采集的南川绣线菊种子在有光条件下的萌发率、萌发速率均显著高于黑暗条件,这种差异随着海拔升高到3250 m,变得不明显。光、暗培养条件对不同海拔锥花小檗种子的萌发率和萌发速率均没有影响。说明海拔和光照条件是造成南川绣线菊种子萌发能力差异的主要原因,而海拔能造成锥花小檗种子萌发能力差异,但光照对其萌发能力没有影响。

The effects of light condition （12 h photoperiod and 24 h dark） on the seed germina- tion of different-altitude Spiraea rosthornii （2500, 2700, 3020, and 3300 m） and Berberis ag- gregata （2160, 2760, 3000, and 3250 m） from the eastern Qinghai-Tibet plateau were studied. The results are as follows ： （1） The seed size of S. rosthornii was significantly negatively correla- ted with altitude, and the seed size of B. aggregata had no significant correlation with altitude. （2） The germination rates of S. rosthornii seeds under light or dark and germination percentage under dark hada significant positive correlation with altitude, but a weak positive correlation was found for germination percentage under light. The germination rate and germination percentage of B. aggregata seeds under light or dark condition had no correlation with altitude, but the germi- nation rate or germination percentage had significant difference among the seeds from different al- titudes. The B. aggregata seeds from 2760 m altitude had the highest germination ability, the higher or lower altitudes both led to lower germination. （3） The seeds of S. rosthornii from differ- ent altitudes had significantly higher germination rates and germination percentages under light than under dark, but the difference was not significant when the seeds were from 3250 m altitude. The light condition had no effects on seed germination rate and germination percentage of B. ag- gregata from different altitudes. These results indicated that the altitude and light condition were the main reasons that led to lower germination ability of S. rosthornii seeds. For B. aggregata, the seeds from different altitudes had different germination abilities, but light condition had no effects on the germination.