| Using OlympusⅨ81 fluorescence covert microscope with its DP71 single-chip color CCD camera software,the physical characteristics of female parent sterile lines of pistils and glumes were measured,pollen amount of male parent restorer lines were analyzed and calculated,and the pollen viability of male parent restorer lines were investigated in artificial climate box.Stigma vigor of sterile lines were determined,and the flowering habits,the prediction and adjustment of flowering period of sterile lines in hybrid seed field and male restorer lines were investigated also.Influencing factors and formation mechanismes of ourcrossing and variation of outcrossing rate were systematicly studied on hybrid japonica rice seed production in Northern China.Meanwhile the outcrossing characteristics,and the methods of prediction and adjustments of flowering with large-area hybrid japonica rice seed production and were studied,with a view to provide a theoretical guidance for high-yielding hybrid rice seed production.1.There were variety differences in blooming time and blooming period among different sterile lines and male restorer lines.If a couple of CMS(sytoplasm male sterile) and male restorer line were chosen,that the optimum combination of the parents' blooming time and blooming period should been realized to ensure synchronization of flowering.There were obvious variety differences in blooming period characteristics among different sterile lines and restorer lines.The traditional standard of synchronization of flowering which using initial heading as judgement should be changed.And full-bloom stage should be used as the new standard for synchronization flowering.2.The coefficients of stigma vigour of sterile lines were as followes from strong to weak: Liao 846A,Liao 02A,Liao 60A,Liao 99A,Liao 30A,Liao 39A,Liao 105A,Liao 5216A, Tijin A,Xiuling A.The trend of outcrossing rate of corresponding sterile lines was similar with the coefficients of stigma vigour.It means that the stronger the coefficients of stigma,the higher the outcrossing rate of sterile lines.3.Correlative analysis showed that there was a significantly positive correlation between stigma angle and stigma exsertion rate under closed-glume of sterile lines.There was a linear positive correlation between stigma exsertion rate under opened-glume and stigma exsertion rate under closed-glume of sterile lines.There were positive correlations between sigma area, stigma length,stigma width,opened-glume angle and stigma exsertion rate under closed-glume.Truthes were like that the bigger the stigma angle of sterile,the higher the stigma exsertion rate under closed-glume,and the higher the stigma exsertion rate under opened-glume,the higher the stigma exsertion rate under closed-glume.The stigma exsertion rate under closed-glume and the stigma exsertion rate under opened-glume didn't depend on someone characteristic but on comprehensive effects of all characteristics.There were significantly and extremely significant positive correlations between stigma exsertion rate under closed-glume,stigma exsertion rate under opened-glume,flowering rate before noon,stigma volume of sterile lines and outcrossing rate.There were negative correlations between outcrossing rate and stigma exsertion rate under closed-glume,stigma exsertion rate under opened-glume,flowering rate before noon,stigma volume.The outcrossing rate,stigma exsertion rate under closed-glume,stigma exsertion rate under opened-glume,flowering rate before noon and stigma volume of sterile lines built up a multiple regression equation as:y=-9.44+0.36x1+0.17x2+0.20x3+1.41x4(p＜0.01,the regression equation was extremely significant).To achieve a higher outcrossing rate of sterile lines,the stigma exsertion rate under opened-glume,flowering rate before noon and stigma volume,especially stigma exsertion rate under closed-glume should be positively chosen.The direct path coefficient of stigma exsertion rate under closed-glume to outcrossing rate was the biggest.Because the indirect path coefficients of stigma exsertion rate under opened-glume, flowering rate before noon and stigma volume were smaller,so the outcrossing rate of sterile lines in a greater degree.The direct effects of stigma exsertion rate under opened-glume, flowering rate before noon and stigma volume of sterile lines on outcrossing rate were smaller, but the indirect effect of stigma exsertion rate under closed-glume of sterile lines on outcrossing rate was bigger.In the aspects of sterile lines choosing and high-yielding seed production of hybrid japonica rice,the key point was improving the stigma exsertion rate under closed-glume of sterile lines,meanwhile improving stigma exsertion rate under opened-glume,flowering rate and choosing stigma with bigger volume.4.The pollen viability of six male restorer lines was decreased with off-body time prolonged,and under the treatment of over 33℃high temperature stress,the longer the treatment time,the more descent range the viability.There were significant differences of injury degrees among different hybrid japonica rice restorer lines,cause of their different indica-compatibility.Rice pollen couldn't tolerate high temperature.Pollen viability was decreased with off-body time prolonged.Under the treatment of over 33℃high temperature stress,the longer was the treatment time,the more was the descent range.There were significant differences in heat tolerance of pollen viability among different hybrid japonica rice restorer lines.It could be used for improving the heat tolerance of hybrid japonica rice restorer lines and breeding new varieties.There was a extremely significant linear positive correlation between pollen amount and stigma length of hybrid japonica rice restorer lines.Though the correlation coefficient of pollen amount and stigma width was big,it did not reach significant level.There was a very significantly linear positive correlation between pollen amount and anther area of hybrid japonica rice restorer lines.There was a very significantly linear positive correlation between pollen amount and anther volume of hybrid japonica rice restorer lines.It meant that the larger the anther length,anther width,anther area and anther volume,the more the pollen amount of hybrid japonica rice restorer lines.Meanwhile it meant that anther length,anther width,anther area and anther volume were closely related to heredity of varieties. 5.Hybrid japonica rice seed production was forecasted by stripping and counting young panicle,leaf-age regression,leaf-age remainder and daily growing velocity,which all obtained good results.By leaf-age remainder forecast,the top 3rd leaves should be judged by second bi-zero leaf and GDOP,to avoid the inaccuracy of leaf-age remainder forecast.6.In the panicle initiation stageⅢof male parent hybrid japonica rice C4115,the spike differentiation process was delayed by controlling water,increasing N,using Paclobutrazol,picking off leaves treatment and so on.The effect of any single treatment was as followes:by picking off leaves＞by using Paclobutrazol＞by increasing N＞by controlling water.Additive effects of many treatments were better than that of any single one,but the additive effects were less than the sum of all the single treatment.There were significant negative effects on plant height and pollen amount per plant by picking off leaves and using Paclobutrzol.Using excessive Paclobutrazol resulted in spike degradation and bear top. Picking off leaves and using Paclobutrazol combined with increasing N showed complementary effects.
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