The results indicated that the seed germination rate and germination index were low,seed activity was weak, the seed was not able to bear storage and the seedlings growing was bad of Japonica giant embryo rice with storage more than two years,but the seed activity was strong,and seedlings growing was very good of new harvest seeds.

[Objective]The study aimed to explore the rational cultivation mode that was in favor of the growth of flag leaf in Japonica giant embryo rice.

In order to study the germination and the ability of preharvest sprouting resistance of different mature degrees of Japonica giant embryo rice seeds,the seed and panicle germination experiment of different days after flowering of Japonica Xi-giant embryo-1 was conducted,the local variety of japonica rice Hexi-22-2 as control.

Root morphological and physiological characteristics of japonica super rice Shennong 265 were studied.

Root developing trends and morphological characters in different growth stages were studied with japonica hybrid rice combination and its retainer and restorer and conventional varieties.

The cloned bacterial blight (BB) resistance gene Xa21 was transferred into C418,a major restorer line of japonica hybrid rice in China,using an Agrobacterium-mediated system.

Analysis of heterosis in two-line Japonica hybrid rice under different environments;