温度对江南油杉种子萌发特性的影响

摘要

In order to discuss the differences of seed germination from different populations and its rela-tionship to temperature,we set five constant temperature conditions (15 ℃,20 ℃,25 ℃,30 ℃ and 35 ℃)and two variable temperature conditions (15 ℃/25 ℃ and 20 ℃/30 ℃)to detect the effect of temperature on seed germination characteristics of Keteleeria fortunei var.cyclolepis by variance anal-ysis,multiple comparisons,correlation analysis and interpolation polynomial.The seeds were from four different populations(Funing,Bobai,Wangmo and Lingyun).The results showed that the optimum temperature of seed germination was 25 ℃ among the seven temperature conditions.The seeds from Bobai populations had the highest germination rate and germination index,but the shortest germina-tion delay and germination duration.Promotion effect of variable temperature conditions on seed ger-mination was different among different populations.Only it had promotion effect on few germination index at 20 ℃/30 ℃.There was no significantly correlation between germination value and environ-ment factors,but germination value and thousand kernel weight of seed had significant positive corre-lation.On the contrary,it was significantly and negatively correlated with seed width.Comparing two kinds of function model,Lagrange Interpolation Polynomial could reflect the relationship between ger-mination value of K.fortunei var.cyclolepis and temperature more accurately.Regression analysis was used to establish the function model of germination value and temperature.Germination value of K.fortunei var.cyclolepis was highest (511.37)at 27.3 ℃ by the prediction of Lagrange Interpolation Polynomial model.%以富宁县、博白县、望谟县、凌云县4个种源江南油杉种子为试验材料,通过设置5个恒温条件(15,20,25,30,35℃)和2个变温条件(15 ℃/25 ℃、20 ℃/30 ℃)结合方差分析、多重比较、相关分析以及插值多项式等方法研究不同种源江南油杉种子萌发特性对温度的响应,探讨不同种源间种子萌发差异及其与温度的关系.结果表明,7个温度条件中,江南油杉种子在25 ℃下萌发效果最好;博白种源种子萌发率、萌发指数最高,萌发时滞和萌发历期最短;变温条件对种子萌发的促进作用因种源而异,只有20 ℃/30 ℃对少数萌发指标有促进作用;江南油杉种子萌发值与环境因子无显著相关性,与种子千粒重呈显著正相关,与种子宽呈显著负相关.采用回归分析建立萌发值与温度的函数模型,并通过模型预测,当温度为27.3 ℃时,江南油杉种子萌发值最大(511.37).