The invention discloses a breeding method for bilinear ultra-small
embryo hybrid rice and belongs to the technical field of special rice
seedling. Bilinear sterile line and restoring line immature embryos to be mutagenized are subjected to
in vitro tissue culture induction to form
callus, 60 Co-gamma rays with the dosage being 11 to 15Gy are utilized for
irradiation treatment, ultra-small
embryo property mutants are obtained, then, the ultra-small
embryo bilinear sterile line and restoring line are breaded through selecting properties of
agriculture, yield, flowering and the like, and further, the bilinear ultra-small embryo
hybrid rice combination is formed through matching. The content of the embryo is reduced through the breeding method, and the
endosperm specific gravity improvement is reached, so the goals of improving the grain thousand seed weight, the yield and the polished rice rate are reached. The breeding method provided by the invention has the advantages that the ultra-small embryo property
mutation frequency reaches 0.01 to 0.02 percent, the embryo weight of the breaded bilinear ultra-small embryo
hybrid rice only accounts for 1 to 1.2 percent of the coarse
rice grain weight, the size is only 1 / 3 to 1 / 2 of that of the ordinary rice embryo, and the polished rice rate is improved by 1.5 to 2.5 percent through being compared with that of the ordinary rice.