Comparing Analysis on the Superiority of Hybrid Japonica Rice and Conventional Japonica Rice in the Rice Growing Regions of Northern Zhejiang Province

[Objective] The aim was to supply references for breeding high-yield combination of hybrid japonica rice and its popularization.[Method] With the region test results of hybrid late japonica rice and conventional late japonica rice in Jiaxing city in 2002～2006 as materials,the comparing analyses were conducted on their character specialties.[Result] Compared with conventional japonica variety,the tillering rate,plant height and grains per spike of the japonica hybrid combinations had stronger competing superiority,but it had less available spikes,lower panicle setting rate and seed setting rate and no significant in increasing yield.Its blast resistance enhanced significantly,but its bacterial blight resistance was a little weak.Its chalkiness grain rate and transparency got some improvement and alkali spreading value got some decrease,but its other quality characters had no difference to that of conventional japonica rice.The characters of the japonica hybrid combinations such as tillering rate,growing period,grains per spike,seed setting rate and 1000-seed weight had positive relation to the yield to different degrees,but its plant height had negative relation to the yield.[Conclusion] The new high-yield combination of hybrid japonica rice in the rice growing regions of northern Zhejiang province should develop into the direction in which the spike,grain and weight should be overall considered.