Basic Studies On The Dual-purpose Genic Male Sterile Rice C815S And Its Homologous Plant Lines

C815S and its homologous plant lines belong to a dual-purpose genic male sterile line with its fertility alteration co-controlled by two factors, temperature and daylength. Its botanical morphology, photo-thermo combining effect, sterile critical temperature and daylength, propagations, outcrossing character, photo-sensitivity, wide compatibility, combining ability, heredity of the heading time and sterility were systematically studied and further discussed in this dissertation .The main results are as follows.1. C815S and its homologous plant lines had the ideal plant and leaf types and the developing root system. Their length of the flag leaf was between 50.0-60.0cm and its opening angle was less than 7.5° , thus it owned the character with long ,erect and narrow .The second and third upper leaves were longer and wider than Per'ai64s .The total leaf number was 16-17 leaves with the period from seeding to heading of 90-107d at the early seedling season while it was 14-15 leaves with the period of 74~85d at the late seeding season among the homologous plant lines .The leaf appearance number was much and its rate was quick .The stem was thickset. Root growing ability was strong at the seedling stage and the root system was developing at the later developmental stage .The ability of cold tolerance was strong at the seedling stage.2. The fertility fluctuation of C815S and its homologous plant lines was more stable than Pei'ai64S. The homologous plant lines had the different fertility fluctuation stage under the Changsha district in 2004. The results showed that 3MS135 had two fertility fluctuation periods, and C815S and 3MS136 had only one, but 3MS138 and 3MS148 had no when Pai'64S had three fluctuation periods.3. C815S and its homologous plant lines had an obvious photo-sensitivity in the fertility expression. Particularly, the sterile critical temperature descended under the long daylength condition while it ascended under the short daylength condition. The different plant lines had not the same fertility photo-sensitivity. The fertility of C815S and its homologous plant lines was co-controlled by dual factors of temperature and daylength. Under the long daylength of 14h condition, the sterile critical temperature was under 22.0 °C while under the short daylength of 12h condition it was above 23.0°C, thus this character could realize the resolute safe hybrid seed production and the propagation with the high and stable yield. Further survey showed that there was a remarkable different in fertility photo-sensitivity among C815S and its homologous plant lines.4. The critical temperature of fertility alteration was low under the natural condition in Changsha from July of 2004 to mid-August. The critical temperature of inducing sterility of C815S and its homologous plant lines was under 22.5 °C. Particularly, the critical temperature of 3MS044 and 3MS135 was between 21.9-22.5 "C, and that of 3MS138, 3MS136 and 3MS148 was less than 22.0°C. Therefore, it was deduced that C815S was the typical low thermo-sensitive genie male sterile line and its inheritance of critical temperature might be controlled by multiple micro-gene.5. The sterile critical daylength of C815S and its homologous plant lines was shorter than Pei'ai64S.The fertility alteration critical daylength was between 11.5-13.Oh by 5d of 23.0°C treatment. This daylength range was under that(13.32~13.83h) of Changsha from July to mid-August.6. The photo-thermo-sensitive periods of inducing the fertility alteration of C815S and its homologous plant lines by daylength and temperature was from the stamen and pistil formation stage to pollen mother cell meiotic division stage and the most sensitive period was atpollen mother cell formation period.7. The fertility alteration of C815S and its homologous plant lines had the photo-thermo interdymatic effect. The sterile critical temperature manifested the falling trend with prolonging the daylength while it presented the ascending trend with shortening the daylength. The model of photo-thermo interdymatic effect, U-model, was put forward according to the continuous change character of the photo-thermo-combining effect on C815S and its homologous plant lines and Pei'ai64S fertility. This model could concretely appraised the index of photo-thermo-complementary, practicability of every PTSGMSR and the hybrid production risk of every ecological rice-growing region.8. The outcrossing characteristics was excellent. The flourishing flowering time of C815S and its homologous plant lines was concentrated during 2~6d after heading. The daily-flowering peak was at 09:30-12:00 and the spikelet opening time was about 2.5h. Its stigma exsertion rate was high. The clasping spikelet rate was very low and the outcrossing-seedy potentiality was high. C815S and its homologous plant lines was sensitive to 920 and the optimal concentration to relieving the clasping-neck of the sterile line was 15.0g/667m2.9. The optimal propagation condition was that C815S and its homologous plant lines was irrigate with running cold water of 20.0-20.5 °C temperature under the short daylength condition. Then the average seed setting rate of C815S and its homologous plant lines was above 72.0% and the highest rate could reach 88.2%.10. C815S had a good combining ability. Its general combining ability of panicles per plant, total grains per panicle, seed setting rate, 1000-grain weight and grain weight per plant was comparatively high, and C815S' heterosis ,combined with 527,9113and Z02, was very obvious. Therefore, C815S was a dual-purpose genie male sterile line of excellent agronomical characteristics.11. The wide compatibility of C815S and its homologous plant lines...