Variation of agronomic characters of introgression lines carrying wild rice, Oryza officinalis (C genome), traits in cultivated rice (O. sativa, A genome) background

In order to develop a rice with high amount of biomass, the variation of the agronomic characters in the progenies (Fsub(4)) from the cross between cultivated rices, O. sativa (A genome) and a wild rice, O. officinalis (C genome) (Norin 29 (4n)/O. officinalis//Koshihikari) was investigated. Fourteen percent lines of the progenies showed spread plant type as well as 12% lines of the progenies showed resistance to bacterial blight pathogen as those of the wild rice. The results indicate that these line of the progenies at least carry the chromosome segment in the wild rice. Regarding agronomic characters, a large number of the progenies indicate much top dry weight and straw weight compared with those of parents or control varieties, such as Akenohoshi, Kusanohoshi and Hoshiyutaka etc. On the other hand, the size of grain in almost of the progenies was similar to those of the cultivated varieties, while some lines of the progenies showed much variation in heading date and plant type. As the result, it is suggested that there is a high possibility of getting a new rice with much biomass compared with that of the present cultivated rice from this breeding method.