Studies On Applied Basis Of Dual-purpose Genic Male Sterile Rice LongS

The botanical morphology,sterile critical temperatur,propagations condition, outcrossing character,combinations ' heterosis and rice blast resistance of Long S were studied,the main results are as follows:(1) Long S has ideal plant and leaf types,its length of the flag leaf was between 35-43cm and its opening angle was 6.9°,thus it owned the character with long,erect and narrow.Its plant height was 64.73cm and the stem was thickset.The glume numbers of unit area reached to 50200 per square meter.(2) The period from seeding to heading of LongS was 99-88d during the sowing period from March 20 to June 30,the total leaf number was 15.9 leaves on March 20 seeding,while the total leaf number was 15.6 leaves on June 30 seeding.It can not normally heading if seeding on July 10^th.The effective accumulated temperature(≥12℃) was 1215.9℃,thus it owned the character that was more sensitive to temperature.(3) The out-crossing characteristics of longS was excellent.The peak flowering period of LongS was at 3-6d after heading.The peak daily-flowering period was at 09:00-14:00 and the spikelet opening time was about 2.5 h.The period of the pollen vigor was 4d,the flowering rate before noon was about 59.09%.Its stigma exsertion rate was high.The clasping spikelet rate was very low and the outcrossing-seedy potentiality was high;longS was sensitive to GA₃ and the optimal concentration to relieving the clasping-neck of the sterile line was 15g/667 m².And the most effective stages was on the point of crevasse and just on the crevasse.(4) The critical temperature of fertility alteration was low,The critical temperature of inducing sterility of Long S was under 23.It was deduced that Long S was the typical low thermo-sensitive genic male sterile line and its inheritance of critical temperature might be controlled by multiple micro-gene.(5) LongS had stable fertility.It had only one fertility fluctuation period in different sowing date of changsha district in 2006,2007.The optimal propagation condition was irrigating with running cold water of 19-20.5℃under nature condition, the average seed setting rate was above 40.61%when it was irrigated with running cold water for 5d.(6) LongS had general combining ability of panicles per plant,1000-grain weight and grain weight per plant was comparatively high,and LongS heterosis,combined with R358,26979,was very obvious,therefore,longS was excellent agronomical characteristics.(7) LongS shows broad-spectrum resistance to varieties blast isolates.such as IC-17,ES6,110-2,87-4,318-2,KJ201,107-2,193-1-1 and so on.After the investigation to the F1 generation of combinations combined with longs,we find LongS was controlled by main dominance effect gene.