The Study Of The Applicable Characteristics Of Several Newly-developed Photoperiod/Thermo-sensitive Genic Male Sterile Lines Of Japonica Rice

The agronomic characters, fertility, flowering habits, crossing performances, combining ability and heterosis analysis of five newly-developed photoperiod/ thermo-sensitive genie male sterile (P(T)GMS) lines ofjaponica rice have been studied in this thesis. The main results as follows:1. The five newly-developed japonica P(T)GMS lines were planted in Wuhan in 2002, represented uniform agronomic characters respectively, indicating a stable heredity of the agronomic characters. Among those, 118, 117 and Y27S have large panicle and thick spikelet density, B30S has tight plant type and strong tillering power, 116 has low plant and thin spikelet density. The average days from sowing to initial heading of B30S, Y27S, 118, 116 and 117 is becoming shorter sequentially.2. Stable sterility period of the P(T)GMS lines is longer than control N5088S, but shorter than control AnNongS. The percentage of self fruited during fertility period is all lower than the controls, thereamong, B30S and 117 are lower than 10%. Y27S, 116, 118, 117 show photoperiod sensitive, while B30S shows thermo-sensitive.3. Flowering duration of single plant and single panicle of Y27S is the shortest, 118 is close to control N5088S. B30S, 116 and 117 are comparatively longer. Flowering kinesis every day in a panicle of Y27S, 116, 118 and 117 is similar to that of restorer line 41678, but B30S' lags behind 41678's, control N5088S is earlier than its. Flowering kinesis in a day in a panicle of Y27S, B30S and control N5088S is close to that of 41678. Although the anthesis time of 116 is dispersed, its flowering is earlier and forenoon flowering rate is relatively higher. The anthesis time of 117 is concentrated but the flourishing flowering is late, while 118's is dispersed and late.4. Spikelet opening time of 116 and 118 is the longest, 117's is relatively short. As for the stigma exsertion rate, 118's is the highest, 116's is the lowest, that of 118, B30S and 117 is more than 60%. The lasting time of the stigma vitality of Y27S is the longest. The fall of the stigma vitality of control N5088S is the slowest. All the P(T)GMS have higher wrapround spikelet rate and relatively lower indehiscent spikelet rate.5. The variance analysis of combining ability showed that the general combining ability of the parent' characters has an important effect on the performance of FI hybrid than the specific combining ability. Contrast to control N5088S, the GCA effects of the grain weight per plant (GWP) of the tested P(T)GMS have no significant difference. InY27S, 117 and 118, the number of spikelet (NS), filled grains per panicle (FGP) and spikelet density (SD) belong to type I or II, and the number of effective panicles per plant (PP), days from sowing to initial heading (DH) and days from sowing to maturity (DM) belong to type III or IV, so they can be used as parents for the high-yield, precocious combinations with large panicle. In B30S, the number of effective panicles per plant (PP) and percentage of seed setting (SSP) belong to type I , so it can be used as parent for the multi-panicle combinations. In population combining ability variance, the additive variance of the grain weight per plant (GWP) is 57.72%, the inadditive variance is 42.28%. While the additive variance plays an important role in other characters.6. The P(T)GMS lines with the potential of application are Y27S and 117. The combinations with general excellent performance are as follows: Y27S/Jin2277, 117/Jin2277,N5088S/41678, 118/GP42, Y27S/C418 and 116/41678.