Analysis on Yield Components of Japonica Rice Varieties in Plateau of Yunnan

Yield and yield components of Japonica rice varieties(lines) were analyzed according to data of Yunnan regional yield test from 2001 to 2008.The result showed thmt yield trend of new varieties(lines) was increased,yield difference between new lines and check variety kept with 359.25-850.95 kg/hm2 in middle area of Yunnan,141.7-927.5 kg/hm2 in middle-north area of Yunnan.Yield components that affected yield improving were grain number and seed setting rate as well as population structure,inheritance of 1000-grain weight were independent and relative stability,so improving 1000-grain weight could get high yield.Correlationship between yield components and yield showed that there was great difference between yield and yield components including grain number,seed-setting rate and 1000-grain weight.