| During the long-term natural selection process,wild rice has reserved abundant variations and has formed strong adaptability to the changes of environment.It is one of the important means to broaden the genetic basis of cultivated rice by mining the potential favorable genes from wild rice and apply them in the genetic improvement of cultivated rice.In this study,a set of chromosome single segment substitution lines(SSSLs)has been constructed through the method of backcross,self-crossing and molecular marker-assisted selection by using O.barthii as the donor parent and elite indica variety “HJX74” as the receptor parent.And,QTLs related to the main agronomic traits were identified.The main results were as follows:1.A total of 76 homozygous chromosome single segment substitution lines have been developed,of which the substituted segment length was different.The total length of substituted segments was 953 c M which was 0.63 times the size of the whole rice genome.The average length of substituted segment was 12.55 c M.And the total coverage length of substituted segments was 540.70 c M,which was equal to 34.48% coverage of the whole rice genome.2.One hundred and sixty QTLs for 14 main agronomic traits were detected in 99 single segment substitution lines that has been constructed by using O.meridionalis as the donor parent.Finally,160 QTLs was detected in 77 SSSLs of 13 main agronomic traits except the trait of the number of panicles.Among of them 5 QTLs for heading date,5 QTLs for plant height,5 QTL for length of flag leaf,15 QTLs for width of flag leaf,11 QTLs for panicle length,4 QTLs for spikelet setting density,10 QTLs for number of primary branch per panicle,11 QTLs for percent seed set,21 QTLs for 100-grain weight,16 QTLs for grain length,27 QTLs for grain width,27 QTLs for ratio of grain length with width and 4 QTLs for peduncle length.The distribution of these traits additive effect percentage is-23.90%(q GWT3-1)~ 31.24%(q GD3).Ten QTLs had the additive effect more than 12%,which were q GWT3-1(-23.9%),q GD4(-17.43%),q SSR3-1(-14.52%),q SSR6(-14.51%),q SSR8(-13.57%),q FLF8(12.64%),q FLF5(13.27%),q GD110(18.04%),q GD5(23.41%)and q GD3(31.24%).3.Based on the substitution mapping,21 QTLs were mapped at an interval less than 10 c M,which were q HD3-1,q PLW5-2,q PL5-1,q PL10,q SSR5,q SSR8?q GWT1,q GWT2-2,q GWT8-1,q GWT8-3,q GL3-1,q GL4,q GW3-1,q GW4-1,q GW5-3,q GW8-1,q GW8-3,q RLW3-2,q RLW5-5,q RLW8-1 and q RLW8-3.4.Among these QTLs,31 QTLs were detected repeatedly in the late season of 2014 and the early season of 2015.The times of the detection is 61 and the average QTL detection times is 2.06.These QTLs were detected from 8 main agronomic traits,which were heading date,width of flag leaf,panicle length,seed-setting rate,100-grain weight,grain length,grain width and ratio of grain length with width. |
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