Abstract: The invention discloses a center lock structure, comprises a chassis, rotary sliding sleeve and a center rod, the top of the rotary sliding sleeve is circumferentially and slidely connected with the chassis; and the center rod is extended into the rotary sliding sleeve along the top of the chassis, an elastic member is provided at one side on the bottom of the center rod, the elastic member is exposed outside the center rod when there is no external force, and the elastic member is concealed in the center rod when squeezed by an external force; in the invention, by the center rod, upper and lower rotary sliding sleeve, through holes and the accommodating grooves for pressing or releasing the elastic member, the structure can be unlocked by rotation and pull-down.

Abstract: The invention discloses a center lock structure, comprises a chassis, rotary sliding sleeve and a center rod, the top of the rotary sliding sleeve is circumferentially and slidely connected with the chassis; and the center rod is extended into the rotary sliding sleeve along the top of the chassis, an elastic member is provided at one side on the bottom of the center rod, the elastic member is exposed outside the center rod when there is no external force, and the elastic member is concealed in the center rod when squeezed by an external force; in the invention, by the center rod, upper and lower rotary sliding sleeve, through holes and the accommodating grooves for pressing or releasing the elastic member, the structure can be unlocked by rotation and pull-down.

Abstract: A method for cultivating perennial rice having perenniality using an asexual propagation characteristic of Oryza longistaminata, wherein a perennial rice carrying a perennial genetic locus of Oryza longistaminata and adapting to different ecological types is cultivated, which makes it possible to harvest for two or more years by means of planting only once, thereby increasing efficiency of rice cultivation and production.