籼型巨胚稻的发现及其遗传育种研究

以若干籼稻品种为材料，通过核辐射诱变于M3代获得巨胚品系。对巨胚性状作了遗传育种分析。结果表明，巨胚属隐性单基因遗传，种胚的大小直接由合子基因型决定，而与为胚发育提供营养的母株基因型、胚乳基因型及细胞质均无关系。因此，可在诱变的M2世代或杂交F2世代的种子上直接进行巨胚性状选择。巨胚稻糙米胚重比原来品种大

Identification, Heredity and Breeding of Indica Giant Embryo Rice

Seeds of several indica rice cultivars were treated by nucleus irradiation and strains with giant embryo were selected in M_3 generation. The genetic and breeding analysis of the traits of TgeB etc. was carried out. The results revealed that the trait of giant embryo was genetically controlled by a pair of recessive genes. The size of rice embryo directly depends on the genotype of zygote, but having no relation to the genotypes of both the female-parent plant and the endosperm providing nutrition to the development of embryo, and also having no relation to the cytoplasm. Hence, it was possible to identify giant embryo mutants directly from seeds of irradiation M_2 or hybrid F_2. The embryo weight of rice with giant embryo was two times as big as its original cultivar, but the 1 000-grain weight and per-plant-yield goes down slightly. In addition, the breeding technology for giant embryo rice was discussed in this paper.