[CH4 emission features of leading super-rice varieties and their relationships with the varieties growth characteristics in Yangtze Delta of China].

A pot experiment was conducted to study the CH4emission features of fourteen leading super-rice varieties( six Japonica rice varieties and eight Indica hybrid rice varieties) and their relationships with the varieties growth characteristics in Yangtze Delta. Two distinct peaks of CH4emission were detected during the entire growth period of the varieties,one peak occurred at fulltillering stage,and the other appeared at booting stage. The average total CH4emission of Japonica rice varieties was 37. 6% higher than that of the Indica hybrid rice varieties( P0. 01),and the differences in the CH4emission between rice types occurred at the post-anthesis phase. For all the varieties,there was a significant positive correlation between the total CH4emission and the maximum leaf area,but the correlations between the CH4emission and the other growth characteristics varied with variety type. The total CH4emission of Japonica rice varieties had a significant positive correlation with plant height,while the correlations between the total CH4emission of Indica hybrid rice varieties and their plant height were not significant. The total CH4emission of Indica hybrid rice varieties had significant negative correlations with the total aboveground biomass,grain yield,and harvest index,but the correlations were not significant for Japonica rice varieties. The lower CH4emission of Indica hybrid rice varieties was likely due to their significantly higher root biomass,as compared with Japonica rice varieties.