OBJECTIVEWe studied the licorice provenance rule under the manual simulative water stress conditions, discussed geographical variation pattern and the ecology mechanism and laid the theoretical basis for the licorice seed regionalization and the seed allocation.

METHODOn the spot we investigated and collected seed materials. Setting up water potential gradient by PEG, we observed the seed germination characteristic through the experiment of indoor germination.

RESULTThe sensitivity of various provenance seed germinative energy show quite remarkable difference for water potential reducing. Along with geographic longitude increasing, the seed germinates variation sensitivity increasing gradually to the water stress. The results of climatic factors' correlation analysis indicated that provenance seed germinate energy to the water stress is sensitive, in which the annual average temperature is low and annual precipitation is abundant. But it is insensitive in which the annual precipitation is little, the annual average temperature, average temperature in July and the annual average ground temperature is high.

CONCLUSIONUnder the water stress condition the licorice provenance seed germination characteristic exists remarkable geographical variation. Geographical variation is the result of natural selection.