Abstract: Based on 1973 MSS and 1990, 2002, 2009 TM remote sensing images, the evolution process and driving force of landscape pattern in Puding County, a typical karst region during past 40 years were analyzed by using GIS, RS technology and landscape ecology research methods. The results showed that the main structure changes of landscape were the mutual conversion between woodland, grassland and farmland. Before 1990, about 43.97% of the woodland and grassland transferred to the farmland; after 1990, 50.09% of the farmland transferred to the woodland and grassland. At the class level, before 1990, the farmland landscape showed a trend of increase in area and of integration in space, while the woodland decreased in area and fragmented in space; after 1990, an opposite trend was found for the woodland and farmland. At the landscape level, before 1990, fragmentation index increased, and the diversity and evenness decreased, indicating that the landscape became simplified. From 1990 to 2002, the landscape shape became complicated, and the diversity and evenness increased. After 2002, the fragmentation decreased, and the discrete and separation degree increased, leading to unstable spatial distribution. All together, in the region with extremely fragile karst ecological environment in Southwest China, ecological restoration project construction and industrial structure adjustment were the main and effective means for ecological restoration in the future.

Key words: SRAP, Fusarium oxysporum of cucurbitaceae, Fusarium oxysporum f. sp. momordicae, genetic diversity