Identification of Wide Compatibility of Intermediate Type Varieties and Indica-japonica DH Lines in Cultivated Rice (Oryza Sativa L.)

The wide compatibility of 95 materials, including intermediate type rice varieties, indica-japonica hybrid DH lines and indica and japonica check varieties, was identified by crossing them to 4 standard indica and japonica testers. The results showed that the compatibility of all tested materials had a continuous distribution, and they could be divided into 4 types, i.e., indica compatible variety (ICV), japonica compatible variety (JCV), wide compatible variety (WCV) and non-compatible variety (NCV), according to the spikelet fertility of their F 1 hybrids. 55 WCVs were identified in this study, among which 18 were from the intermediate type varieties and 34 from the indica-japonica hybrid DH lines. The indica-japonica hybrid DH lines with both WC parents were not only almost all (96.2%) widely compatible but also showed a better wide compatibility than the check Linglun. The indica-japonica hybrid DH lines with non-WC parents could also be widely compatible (25.0%～57.1% of the lines were widely compatible), but showed a slightly poorer wide compatibility. It is concluded that the wide compatibility may be closely related to the indica-japonica differentiation and selection of the intermediate type WC lines is the mainstream in the breeding of WC lines in rice.