抄録
It has been known that lots of plants are rubber yielding besides Hevea brasiliensis. Among them, only Hevea brasiliensis has been actively cultivated to produce rubber. Recently, studies on non-Hevea rubber yielding plants are focused, which seem to become more and more important in this century. In this part, revival of guayule and koksaghyz is specifically noted together with new biotechnological studies, genome engineering, in particular. Based on the analysis of the scientific and industrial trends, several measures for more natural rubber production are proposed from the sustainability viewpoint.
