MOLECULAR GENETIC STUDIES ON THE RICE BLAST FUNGUS POPULATION II.TEMPORAL AND SPATIAL CHRACTERIZATION OF GENETIC STRUCTURE OF THE FUNGUS POPULATION IN 2000 IN GUANGDONG PROVINCE
稻瘟病菌群体的分子遗传学研究II.广东省2000年度稻瘟病菌群体遗传结构的时空特性

Genetic structure of the rice blast fungus population in 2000 in Guangdong Province, China was assessed with RAPD (random amplified polymorphic DNA) markers. 104 isolates collected from three rice-growing regions in early and late seasons in 2000 were divided into 14 genetic lineages drew by unweighted pair group method using arithmetic average (UPGMA) when focused at the similarity coefficient of 0.62. Among the 14 genetic lineages, lineages 5 and 8 both consisted of 26 isolates were recognized as dominant lineages in 2000. Spatial characterization of the genetic structure showed that there is a tendency to increase the genetic diversity from northern to southern regions in Guangdong, and each region has its own specific lineages. Temporal characterization of the genetic structure suggested that there is also a tendency to increase the genetic diversity from early to late seasons in Guangdong, and two major groups corresponding to the two seasons were distinct with similarity coefficient of 0.50. The temporal and spatial characterizations represent in 2000 were similar to those represented in 1998-1999, even though the genetic structures of the populations between 1998-1999 and 2000 were considerably different.