Abstract: The exploration of heterosis in indica-japonica hybrids is an important approach to increasing the yield potential of rice (Oryza sativa L.). Hybrid sterility was a major obstacle for utilization of such heterosis. The wide-compatibility genes provided valuable genetic resources to effectively solve the problem of hybrid sterility for rice breeding. An intermediate line HDH73, which had good agronomic characteristics and wide compatibility gene, was bred by anther culture with indica-japonica hybrid Yongyou 4949 as donor. The high-throughput SNP (single nucleotide polymorphism) genotyping showed that the indica/japonica classification of HDH73 was partial japonica, and the frequency of japonica loci of HDH73 accounted for about 2/3 by SNP analysis with polymorphism marker between indica and japonica. The hybrids of Guang 3S/HDH73 and Changlijing S/HDH73 were planted and investigated agronomic characteristics. The growth stages and plant heights of these hybrids were similar to those of the medium-indica hybrids which were widely planted, and the seed setting rate was fertile. The rice line HDH73 could be wide-compatibility resource in breeding program for utilization of inter-subspecific heterosis.

Key words: rice (Oryza sativa L.), wide-compatibility, heterosis, SNP(single nucleotide polymorphism)