4种岩溶山地常见树种种子的萌发特性

Germination Characteristics of Four Kinds of Seed of Karst Mountain Common Tree Species

以岩溶地区常见树种朴树、火棘、青桐和构树为试验材料,探讨种子的萌发特性,旨在为苗木培育提供技术依据。结果表明,种子吸水率呈现快—慢—快的S型曲线变化,其中,构树的吸水率最大,平均吸水率从大到小排序为构树>朴树>火棘>青桐;火棘的吸水停滞期最短,为5 h;火棘、构树和朴树发芽的最适温度是白天30℃晚上20℃(30/20℃)变温,而青桐是30℃恒温;种子随着PEG溶液浓度增大,发芽率、发芽势、发芽指数和发芽速度总体呈下降趋势;种子发芽过程的水势范围为0^-0.4 MPa,低于-0.4 MPa种子不能发芽。

In this article, the common trees in Karst area like Celtis sinesis, Pyracantha forluneana, Firmiana platanifolia and Broussonetia papyrifera were selected as experimental materials. The water absorption of all the four seeds showed fast-slow-fast, like S-curve, the water absorption of Broussonetia papyrifera was the highest, the order of the average water absorption was Broussonetia papyrifera 〉 Celtis sinesis 〉 Pyracantha forluneana 〉 Firmiana platanifolia; the deadtime of water sucking of Pyracantha forluneana was 5 hours, which was the shortest. The optimum temperature for the germination of the seed of Pyracanthaforluneana, Broussonetia papyrifera and Celtis sinesis was at a variable temperature of 30/20 ℃, but it was at a constant temperature of 30 ℃ for Firmiana platanifolia. The water stress markedly affected the germination, germinating potential, germination index and speed of germination of seeds of different trees in Karst area, the germination, germinating potential, germination index and speed of germination of seeds of different trees decreased as the concentration of PEG increased. In the process of the germination of the seeds of all kinds of trees, the water potential ranged from 0 MPa to -0.4 MPa, the seeds could not germinate when it belowed -0.4 MPa.