| A mapping population of 130 F10 lines (recombinant inbred lines, RILs ), derived from a cross between MiYang 46 and FJCD ,were used in this investigation . The development of rice qualities in period of grain-filling was observed ,at the same time ,the dynamic QTL mapping was conducted for quality traits and correlation analysis was carried ,so that inner genetic characteristic was reviewed . Besides, photosynthesis and grain-filling rate in period of grain-filling were mapped , in order to illustrate genetic law and influencing factors .the results were as follows:1. The dynamic QTL mapping of qualities and correlation analysisIn twenty QTLs controlling amylose content(AC) ,six QTLs was detected in 12d after flowering ,explaining 49% of phenotypic variation ;three QTLs were detected in 18d after flowering ,phenotypic variation ranged from 5%-17%;six QTLs were located in 24d after flowering ,accounting for 55% of total phenotypic variation ; QTLs controlling AC of 30d after flowering ranged from 5%-12%,collectively explaining 45%of total phenotypic variation.Twenty-four additive effects QTLs were detected for rice soluble saccharine(Ss) in grain-filling period in total .QTLs at 12d after flowering explained 6%-14% of phenotypic variation , QTLs in 18d after flowering accounted for 79% of total phenotypic variation; QTLs in 24d after flowering showed from 5% to 21% ,perfouming for 72% of phenotypic variation ; QTLs in 30d after flowering were located on 1,3,6,11 chromosomes , explaining 58% of phenotypic variation.QTLs associated with sucrose(Su) were located on 1,3,11,12 chromosomes , accounting for 48% in total ; QTLs in 18d after flowering were located on 1,2,4 chromosomes , with low contribution to total phenotypic variation ranging from 5%-7% ;QTLs in 24d after flowering showed 60% of total phenotypic variation ; QTLs in 30d after flowering ranged from 6%-13%.Four QTLs controlling GL were located on 4,5,6,7 chromosomes , accounting for 35% of phenotypic variation ; Eight QTLs controlling GW were located 2,4,5 chromosomes ; Six QTLs controlling GLW were located on 1,2,5 chromosomes ,explaining 42% of phenotypic variation .From the mapping results of three traits in different grainfilling phases ,the investigation only detected QTLs which expressed only in two phases ,but not in all four phases . In the reseach ,the author only detected QTLs controlling two traits, out of three ones (AC,Ss,Su) which expressed in the same or different phases ,such as QTL located on 9 chromosomes ,mark interval RM201-RM242 .2. QTL mapping of photosynethesisThe number of QTLs controlling photosynethesis in four grainfilling phases was 6,6,6,7 ,individually located on 2,8 chromosomes, 1,2,4,7,10,11 chromosomes, 1,2,3,4,6,7 chromosomes,1,2,4,5 chromosomes , respectively explaining 79%,69%,44%,57% of phenotypic variation . Comparing the QTL mapping results in different phases , the author found the QTLs maped the same area on chromosomes in both 12d and 18d after flowering were guessed the same QTL ,its interval was RM213-RM318 on chromosomes .3. QTL mapping of grain-filling rateThe number of QTLs detected in four grainfilling phases was 5,6,9,7 ,which were respectively located on 1,2,7 chromosomes, 1,5,6,7,8 chromosomes , 1,2,3,6,9,11,12 chromosomes , 2,4,9,12 chromosomes ,accounting for 60%,52%,88%,100% of phenotypic variation respwectiviely. Comparing the mapping result in four phases ,we found QTL located on qGFR-2 was detected on 12d,24d and 30d repeatly , showing that the QTL was expressed in different phases of grainfilling.4. Correlation analysis of qualities,photosythesis and grain-filling rateThe analysis among AC in different periods suggested that there were positive and negative correlations, the analysis of Ss showed the positive correlation, correlation analysis of Su was similar to Ss .Negative correlation was reflected between AC and Ss ,but only AC-24d and Ss-24d was significant. Negative correlation was shown between AC and Su, but between Ss and Su there was positive correlation.There were positive correlation among photosynethesis in different phases ,Pn-12d and Pn-18d,Pn-12d and Pn-24d,Pn-18d and Pn-24d,Pn-24d and Pn-30d perfoumed significantly positive correlation .Only GFR-18 d and GFR-24d,GFR-24d and GFR-30d among grain-filling rate correlation showed significant .The correlation between photosynethesis and grain-filling rate showed different results in different phases .The correlation between photosynethesis and appearance traits was positive or negative, but correlation coefficient was low, not up to significant. Between photosynethesis and AC, the correlation in 12d and 18d was negative. But correlation in 24d and 30d was positive .The correlation between photosynethesis and sucrose showed different in different phases,Pn-12d and Su-18d was negative , Pn-18d and Su-12d,Pn-24d and Su-30d were significantly positive.From the correlation analysis between grain-filling rate and appearance traits, there were positive and significant correlation among grain-filling rate,GL and GW, but the correlation between GFR-12 d,GFR-18 d and GLW was positive ,the correlation between GFR-24 d,GFR-30 d and GLW was negative, there was negative correlation between GFR and AC in 12d,18d, but was positive in 24d and 30d.The correlation between grain-filling rate and Ss was obvious at 12d after flowering , namely, the correlation between GFR-12d and Ss-12d,Ss-18d,Ss-30d was significant. The correlation between grain-filling rate and sucrose was negative , and the trend of correlation was similar to Ss. |
