Abstract: Polymorphisms were searched in 24 varieties with large planted acreages in Japan, and the polymorphic sites were compared among the varieties. Thus, polymorphic markers that can be used to distinguish varieties in a simple and quick manner were obtained. The markers showed distinct patterns for each of the varieties, demonstrating that their combination would enable the varieties to be distinguished. Thus, the inventors succeeded in obtaining molecular markers that can distinguish 24 rice varieties. The use of these markers enables closely related rice varieties to be distinguished and identified at the DNA level.

Abstract: A lubricating apparatus for a ball screw which can sufficiently lubricate even in a high load usage is disposed between a ball nut and a screw shaft, and a polymer member containing a lubricant being mainly in slidable contact with an outer diameter portion of the screw shaft is mounted to at least any one of both ends of the ball nut and a space including a ball not-passing space in an inner portion of the ball nut. The polymer member prevents the lubricant attached to the thread groove of the screw shaft from being scraped off during oscillations of the screw shaft, such that the lubricant attached to the thread groove can be efficiently maintained.