Genetic Map Construction Of Rice(Oryza Sativa L.) And The Location Of QTL Associated With Allelopathy Against Barnyardgrass(Echinochloa Crus-galli L.)

The crop production has been significantly affected by paddy weeds,it is always considered to control weed effectively by using herbicide.Hower, it takes great threaten to environment and human's health in this measure.It therefore has been suggested that the application of allelopathy is an alternative weed control method.Progress has been made in rice allelopathy,but it must be paid attention to the researth on locating genes.In this study,the recombinent inbred line (RIL) drived from the crosses by the rice cultivar Lemont(weak allelopathy) with Dular(strong allelopathy) was applied to locate the genes associated with allelopathy against barnyardgrass.The results were summarized as follows:Allelopathic effect of the RIL population and their parents on the receiver plant, barnyardgrass, were detected by relay-seeding co-culture in agar(RCA) .And inhibitory effects of all entries on barnyardgrass root-length and shoot-height showed continuously variant,implying that allelopathy is a quantitative character.The frequency distribution of the inhibitory effect on the root-length of barnyardgrass was close to normal pattern,but that of inhibitory effect on the shoot-height of barnyardgrass showed slightly deviated normal pattern. Accordingly, the inhibitory effect on the root-length of barnyardgrass could be used as a quantitative trait for gene mapping.Variance analysis for the inhibitory effect on the root-length of barnyardgrass indicated that variance between the lines was significant and the reverse was true in the case between the blocks, suggesting that it could be subjected to genetic analysis under variance between the blocks.Banding patterns of every molecular marker fragment were detected by electrophoresis,and molecular marker linkage map in tweleve pairs of chromosomes in rice.The map was comprised of tweleve linkage groups and ninety-eight molecular markers covering per chromosome with 283.26cM span,36.47cM span per two molecular markers and 8.17 molecular markers per chromosome.Five QTLs associated with allelopathy against the target weed were respectively located in 1 1, 5, 9, 9 linkage group,and explained 23.97%, 15.21%, 13.89%, 18.63%, 6.64%...