关键词: DFR, DFR, cDNA克隆, 风信子, 基因

Abstract:

In order to study the cropland changes and its affected factors in a decade more directly, completely and accurately in Zhejiang province, land survey results of last ten years were used to detect the amount of cropland changes and its direct affected factors. The study presented cropland decreased 20.8×104 hm2, 9.8% from 1996 to 2006 in Zhejiang province. Cropland changes had been directly affected by the terrain slope, one of physical affected factors. The cropland decreased faster in flat terrain and steep slope than in gentle slope. Terraced fields increased in gentle slope. Among social affected factors, adjustment of agricultural industrial structure, expansion of the construction land and ecology shifting from agricultural use directly caused the arable land to decrease; strict cropland protection regimes slowed down the trend of arable land decreasing. All in all, the trend of cropland decreasing was inevitable. For social and economic development, cropland protection were all ensured, the more scientific total plan of land use and more strict cropland protection regimes should be made full use.