关键词: 纸坊沟流域, 纸坊沟流域, 退耕还林（草）工程, 生态经济系统, 规律, 驱动力

Abstract: This study was done to improve the ability of the rice cold tolerance and to insure it’s production safely in cold regions. The methods of irrigate with deep cold water and low temperature in climatic laboratory at meiosis were introduced. During 2004-2005, 45 lines were tested and 4 of them were released. It showed that those are important to enrich the resources of germplasm with cold tolerance through international cooperation, to choose the ones in early generation and to make use of multi-methods in breeding of the new rice varieties with cold tolerance.