Sterility of PTGMRS deriving from Nongken 58S germplasm and 5460S germplasm was governed by two pairs of recessive genes, but that of Annong S-1 governed by a couple of recessive major genes. An allelism test involving five PTGMRS revealed that Nongken 58S and W6154S, Nongken 58S and W7415S, Nongken 58S and 5460S, W6154S and Annong S-1, W6154S and 5460S possessed partially identical photo-thermo sensitive sterile genes; Nongken 58S and Annong S-1, W6154S and W7415S, W7415S and Annong S-1, W7415S and 5460S, Annong S-1 and 5460S had different photo-thermo sensitive sterile genes.