Pedigree Analysis of Photoperiod-thermo Sensitive Genic Male Sterile Rice

Abstract

A great progress has been made in two-line hybrid rice in China. Up to 2010, a total of 427 two-line hybrid combina- tions (cultivars) had been registered. In recent years, two-line hybrid rice has become an important type in rice production in China. Photoperiod-thermo sensitive genic male sterile (PTGMS) lines are the basis of two-line hybrid rice. In this paper, the rela- tionship of 130 PTGMS lines used as parents of registered hybrid combinations and/or with the right of protection of new varieties was analyzed, and 126 of 130 PTGMS lines that the relationship defined were traced back to their original PTGMS lines as a starting point. The pedigree of the 73 PTGMS lines used for producing hybrid combinations with large scale planting and/or the right of protection of new varieties was analyzed in detail, and the breeding methods of the 126 PTGMS lines were analyzed. The relationship between the photoperiod-thermo response type and the pedigree of the PTGMS lines was discussed. We also pro- posed that selecting the proper PTGMS materials by pedigree analysis is as important as photoperiod and temperature controlling for studying the molecular mechanism of photoperiod-thermo response in PTGMS lines. Open sharing of the PTGMS resources has the great significance for accelerating the breeding of new practical PTGMS lines and minimizing the adverse environmental