Analysis on Yield and Quality of the Late-maturity Medium japonica Rice Varieties Released in Jiangsu Province in the Last 30Years

In order to understand the breeding situation and trend of the late-maturity medium japonica rice varieties in Jiangsu Province,the regional trial data and yield and quality of forty-five late-maturity medium japonica rice varieties released in last thirty years were analyzed,which would provide a reference frame for the improvement and breeding of new varieties.The regional trial data showed that there were three development phases of yield of the late-maturity medium japonica rice varieties and the representative varieties were Yanjing 2with yield of over 500kg/667m2 bred in1983,Wuyujing 3with yield of over 580kg/667m2 bred in 1992,Wuyunjing 8with yield of over 650kg/667m2 bred in1999,respectively.Yield of varieties bred after 2005was fluctuated around 600kg/667m2.Yield and quality of fortyfive late-maturity medium japonica rice varieties identified at Yangzhou in 2012showed that 1)yield of varieties bred in different periods was all fluctuated from 500kg/667m2 to 600kg/667m2 and had not been developed significantly,2)chalky grains of varieties had been improved significantly,but chalkiness and taste quality of varieties were still needed to be improved.