Abstract: One hundred and sixty-three rice cultivars and lines were used to study the differences of panicle weight index among varieties and its relationship with yield and quality of japonica rice in Shenyang,Gongzhuling,and Wuchang.It was put forward that using panicle weight index (PWI,the ratio of weight per panicle to panicles per hill) to show the relationship of panicle number and panicle type.The results indicated that the average PWI of these materials was 0.155 g/panicle and its 99% confidence limit distributed between 0.109 and 0.200.These materials were classified into heavy panicle type (HPT) and equation panicle type (EPT) or multiple panicle type (MPT).PWI was significantly or very significantly and positively correlated with yield,grains per panicle,primary branch,secondary branches,primary branch grain rate,secondary branch grain rate,large vascular bundles in neck,small vascular bundles in neck,large vascular bundles in the second internode and small vascular bundles in the second internode,plant height,LAI and length and width of the top three leaves,but significantly or highly significantly and negatively correlated with panicles per unit area and basic angle of the flag leaf(BAF),and yield of heavy panicle type was much higher than it of multiple panicle type (MPT).PWI was very negatively correlated with processing quality,nutritional quality,taste value and related indexes,no significant relationship with appearance quality,and quality of multiple panicle type (MPT) was superior to it of heavy panicle type (HPT).PWI is a good index to describe the relationship between panicle number and panicle type.On the basis of stabilizing weight per panicle,appropriate reduction of PWI might be an effective way to improve yield and quality.

Key words: Japonica rice in Northern China, Panicle weight index, Yield, Quality

CLC Number: 

• S511.01