Breeding method of high-heritability indica-compatible japonica rice line

The invention relates to a breeding method of a high-heritability indica-compatible japonica rice line. The breeding method is characterized by comprising the breeding steps: (1) selecting a plurality of different sources of japonica rice type or javanica wide-compatible varieties, and performing convergent hybridization, and selecting strains with formula index more than or equal to 14 from the hybridized segregation progeny; (2) performing test crossing on the progeny strain obtained in the step (1) by selecting indica two-line male sterile line, performing fructification percentage testing on the test crossed F1, and selecting out strains with test crossed F1 fructification percentage more than or equal to 75%; (3) hybridizing strain selected from the step (2) and conventional japonica rice variety, performing self-crossing multiplication on the progeny, carrying out random test crossing on the F4 progeny through the indica two-line male sterile line, selecting the high-fructification percentage strain with test crossed F1 fructification percentage more than or equal to 75%, thus obtaining the high-heritability indica-compatible japonica riceline when the high-fructification percentage strain is taken accounted for more than or equal to 50% that of the tested F4 strain. The breeding method has the advantages that different wide-compatible genes can be recombined through adopting the polymerization hybridization (multiple crossing) of different sources of wide-compatible varieties, and the indica-compatible capability and the heritability of the progeny can be enhanced. A great quantity of different types of indica-compatible japonica rice lines can be bred through hybridization of the high-heritability indica-compatible japonica rice line and the conventional japonica rice variety, so that the breeding method can lay a foundation for the production and application of new prepared indica japonica hybridized rice variety together with the indica sterile line.