Abstract：
The phenomena, intrinsic character, and workable controlling ways as well as identification methodology of fertility stability of P(T)GMS lines have been studied by surveying and analyzing more than 90 P(T)GMS accessions under artificially controlled climatic conditions. Main results are as follows: (1) Both photoperiod and temperature are important factors conditioning fertility alteration of P(T)GMS materials, none of which is of solely photoperiod-sensitive type; (2) There are 3 different types of P(T)GMS lines with regard to their most sensitive stage to temperature for fertility alteration (MSST); (3) The key technique criterion of practical P(T)GMS lines is that the critical temperature inducing male sterility (CTIMS) must be relatively lower and the specific CTIMS should be designed based on the historical meteorological data in local areas; (4) CTIMS will inherently drift up if parent seed multiplication is normally conducted without any artificial selection. The appropriate criterion of CTIMS of practically usable P(T)GMS lines incentral China rice-growing area and the possibility of controlling drift of CTIMS are discussed. And themost effective way to control the drift of CTIMS within the permission of commercial seed production is the procedure of core seed and foundation production.
1998, Vol. 12 
