Abstract
As a part of series of fundamental studies on the Renge breeding, effects of inbreeding on fcrage yield, plant height and seed fertility during four generations were investigated. The significance of inbreeding in the Renge breeding was also discussed in this paper. The results obtained are summarized as follows : ( 1 ) Renge showed a marked decline in the vegetative vigor by selfing. On the average, the forage yield of the lines tested dropped to about 60% of the parental yield in the first selfed generation. In the fourth generation, a little over 30% of the original vigor remained. There were considerable variations in the decline of forage yield by inbreeding, but no strain without decrease in yield: as compared with the parent was obtained in this; study. The reduction in plant height was not so, marked as in fcrage yield, but selfing through four generations caused 40% decrease from the parent in the plant height. ( 2 ) Seed fertility was not decreased by inbree-ing. This is a desirable point in considering the breeding procedure in which heterosis occurring in the hybrid between inbred lines is utilized. ( 3 ) During the experiment, the inbred line wrth "Leafiness" was obtained, which was one of the most valuable characteristics in forage crops, , (see Fig. 2).
