| Developing and growing high yield rice varieties is one of the most effectiveapproaches to solve the crisis of food shortage. The detection and pyramiding of QTLsrelated to rice yield will lay a good foundation for the improvement of complicatedtargeted traits of main crops. In the present study, a total of5selected introgression linesfrom the population between recurrent parent (Minghui86) and donor parents (ZDZ057,Fuhui838and Teqing) were used to develop4pyramiding populations: WD135/WD190,WD190/WD250, WD208/WD258and WD135/WD258. Finally,12,17,27and35pyramiding lines were selected respectively. Yield and its related traits of pyramiding F4swere evaluated in the normal paddy field. The pyramiding populations were genotyped byusing55polymorphic SSR markers. One-way ANOVA and Chi-square Test were appliedto identify QTLs in pyramiding populations.1. The performance of phenotype in four pyramiding populationsThe significant variations among genotypes for panicle length and yield wereobserved in all four pyramiding populations. For heading date, no significant variation wasobserved in any populations. The genotypes for other traits vary among populations. In the4pyramiding populations, there were57higher yield pyramiding lines with0.36%72.7%increased yield, and about44pyramiding lines showed higher yield than betterpyramiding parents. Compared with recurrent parent and pyramiding parents, paniclenumbers per plant, filled grain number per panicle and spikelet number per panicle wereincreased significantly. Spikelet fertility and1000-grain weight were also improved insome high yield pyramiding lines.2. The correlation of yield and its component traits in four pyramidingpopulationsAmong the9traits related to yield and its component, yield per plant was correlatedor significantly correlated with panicle per plant, filled grain number per panicle, spikeletnumber per panicle and spikelet fertility percentage in four populations. However, yieldper plant was not in correlation with1000-grain weight. In addition, filled grain numberper panicle was significantly correlated with spikelet number per panicle. The correlationsamong other traits vary among populations.3. The QTLs detected related to yield and its component traits in four pyramiding populations by Chi-square test and One-way ANOVA22QTLs related to yield were detected by Chi-square test. Among these QTLs, RM14,RM240, RM55, RM276, RM108and RM229were also detected by other researchers inother populations. In addition, RM1146was detected in pyramiding population1and2;RM222was detected in pyramiding population2,3and4.20QTLs related to yield and itscomponent traits were detected by One-way ANOVA, viz.1QTL related to yield per plant,5QTLs related to1000-grain weight,2QTLs related to spikelet fertility percentage,2QTLs related to filled grain number per panicle,2QTLs related to spikelet number perpanicle,1QTLs related to panicle number per plant,2QTLs related to panicle length,4QTLs related to plant height and1QTL related to heading date. Among these QTLs,qPLP6-1qSNP9-1qSFP2-1and qGWP9-1were also detected by other researchers byusing different populations. These results indicated that the method of QTL mapping weadopted was effective. It provided a new approach for detection and pyramiding of QTLsrelated to complex target traits.4. The pyramiding effects in four pyramiding populationsIn comparison with the better introgression parental lines,9pyramiding lines withsignificant high yield were identified in the four pyramiding populations. Compared withthe recurrent parent and the parents of pyramiding populations, the significantly improvedfilled grain number per panicle and spikelet number per panicle resulted in the increasedyield in nine higher yield pyramiding lines. Panicle numbers, spikelet fertility percentageand1000-grain weight were also improved in some lines.We conducted the analysis of QTLs effects in9pyramiding lines and compared themwith the identified QTLs in parental lines. The results showed that some favorable QTLsfrom parental lines were integrated in the pyramiding lines. |
PDF Full Text Request