Seed germination and ecological adaptability of Delavaya toxocarpa Franch. in Karst region.

【Objective】 The germination and ecological adaptability of wild Delavaya toxocarpa Franch.seeds in Karst region were studied to provide scientific references for ecological restoration and reconstruction in Karst region.【Method】 Using the method of direct sowing,lab test and field trial,the effects of temperature and soil moisture content on seed germination and seedling sprouting of Delavaya toxocarpa Franch.were observed.【Result】 The Delavaya toxocarpa Franch.seeds had the average size of 12.62 mm×12.23 mm,100-seed weight of 83.69 g,moisture content of 22.28%,and vitality of(96.66±3.06)%.The results showed that seeds of Delavaya toxocarpa Franch.could not germinate at 5/15℃,but their maximal germination rate(66.88±1.48)% was at 25/35℃ under 12-hour lighting.The peak germination rate(23.00± 1.58)% occurred when silver sand moisture content was 30%-40% of saturated soil relative moisture capacity.Too much moisture in soil negatively influenced seed germination.【Conclusion】 Seed germination of Delavaya toxocarpa Franch.presented high ecological adaptability to microhabitat in Karst region.In terms of Delavaya toxocarpa Franch.forest plantation,indoor poikilothermic treatment of seed and seedling direct sowing are beneficial for improving germination rate.