| Rice blast,Brown planthopper(BPH)and Bacterial blight(BB)are the main three disease and pests which can cause devastating effect on the yield and quality in the production of rice during the epidemic area.Rice is the staple crop for more than half of the world’s population,therefor the losses of rice production would not only cause food security crisis but also impact the environmental because of excessive application of chemical pesticide for controlling these disease and pests.R1813 which was developed by The Seed Company of Hunan Longping is an elite high-yielding,lodging-resistance and late-maturing indica restorer line which had made some combinations passed the examination as the male parent.In this research,the blast resistance gene Pi9,the BPH resistance gene BPH14,BPH15 and the BB resistance gene Xa23 from the donor parents MD12086-41 were introgressed into the genetic background of R1813 by using molecular marker-assisted selection,phenotypic selection,crossing and backcrossing technologies.we expect to develop some new breeding lines that the agronomic traits are similar to R1813 and the resistance of blast,BPH and BB will be enhanced significantly.The main results are as follows:1.We selected seven new breeding restore lines harboring Bph14,Bph15,Pi9,Xa23,which were designed as ST15005-1-280,ST15005-1-284,ST15005-1-8-9,ST15005-1-106-9,ST15005-1-318-1,ST15005-1-318-4 and ST15005-1-318-14,and one breeding line designed as ST15005-1-206 harboring Bph14,Bph15 and Xa23 from the offspring of MD12086-414/R1813.The agronomic traits of all the eight selected lines are similar to the recipient parent R1813.2.The results of identification of resistance to BPH showed that the resistance score of four breeding lines,ST15005-1-206,ST15005-1-280,ST15005-1-8-9 and ST15005-1-318-14 were resistant to BPH(3 grade)and three breeding lines,ST15005-1-106-9,ST15005-1-318-1 and ST 15005-1-318-4 were moderate resistant to BPH(5 grade).3.The results of identification of resistance to BB showed that all the eight breeding lines performed resistance or highly resistance to two Xoo strains ZHE173 and GD1358.4.Using the method of natural inducement in blast epidemic field,the results of identification of resistance to blast showed that the comprehensive resistance index of all the eight breeding lines range from 1.0 to 2.3,dramatically improved to blast thanthe recipient parent which the comprehensive resistance index is 5.5.Thirty five Xoo strains were used to identify the resistance spectrum to blast through artificial inoculation,the results showed that the resistance frequency of all the breeding lines range from 91.43% to 100%,higher than the recipient parent R1813 that the resistance frequency is 77.14%.5.By investigating the yield,main agronomic traits,and rice quality of all the breeding lines,the results indicated that the yield of all the breeding lines is similar to rice line R1813 except two lines ST15005-1-206 and ST15005-1-318-1 significantly lower than R1813.The main agronomic traits of all the breeding lines are similar to R1813 except the seed-set rate that generally below the R1813.The rice quality of three lines ST15005-1-280,ST15005-1-284 and ST15005-1-8-9 were a litter bad,the others perform good as the R1813.6.The results of identification of heterosis about these combinations showed that five combinations,Feng39S/ST15005-1-318-1,Feng39S/ST15005-1-318-14,Hua5282S/ST15005-1-318-1,Hua5325S/ST15005-1-106-9 and Hua5325S/ST15005-1-318-4 had a good comprehensive performance,behaving higher yield and better rice quality.We still need to produce these hybrid seed and do the test of comparing their yield in different region in future. |
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