Mapping Quantitative Trait Loci (QTL) For Rice Planthopper Resistance Of Changhui891/02428 Backcross Inbred Lines

Rice is one of the most important food in the word, which is heavily influenced by the planthopper. all the time. Traditionally, people rely on chemical pesticide to control planthopper. the excessive use of chemical pesticides not only cause a huge damage to environment but also give a threat to food security. nowadays, the using of the resisitance variety has proved as a effective way to control the planthopper in practice. Changhui891,the indica restorer, bred by Jiangxi Agricultural University and strong resistant to brown planthopper, 02428 is a typical japonica and show poor resistance to brown planthopper capacity. In order to detect the gene?QTL? associated with planthopper, a BILs population, comparing 125 BC1F5 lines, were developed by continuous crossing Changhui891 to 02428. meanwhile a high-density genetic map of the 125 BC1F5 lines was constructed and used for brown planthopper QTL mapping. The main results are as follows:?1? By using the RAD?restriction-site-associated DNA sequencing,? technology, a total of 4171 polymorphic SNPs has be developed for the 125 pedigrees backcross inbred line analysis, QTL Icimapping 4.0.6.0 was used for the high-density genetic linkage map construction. for the high-density genetic linkage map, there are 75 SNP markers on chromosome 1, the total genetic distance is 60.65 cM; 186 SNP markers on chromosome 2contains, the total genetic distance is 48.62 cM; the SNPs are131,125,133,94,130,139,105,348,96 and 129 on choromosme 3,4,5,6,7,8,9,10,11,12 respectively, the total genetic distance is 55.43 cM,100.46 cM,64.40 cM,59.40 cM,62.07 cM,43.90 cM,65.51 cM,98.49 cM,121.38 cM and 131.36 cM for choromosme3,4,5,6,7,8,9,10,11 and 12. This map could meet the requirements of resistance QTL detection.?2? According to the seedling population screening method, the parents were used to analyze the resistance ability to the planthopper in seedling stage. The results showed that,Changhui891 is a medium resistance variety, 02428 is easily susceptible to the planthopper.the QTL analysis were carried out for the BILs population, and a major resistance QTL qBPH-12-1 was detected located between Chr12₁8281452 and Chr12₁8169641, on chromosoeme 12, the LOD value is 2.9934, the phynotypic explanation by qBPH-12-1 is11.9755%. The positive allele of qBPH-12-1 is from Changhui891.?3? In the field heading display natural resistance by statistical appraisal,The average number of Changhui891 insect population is 0.33 per plant,The average number of02428 insect population is 2.00 per plant,Parents there are significant differences.Theaverage number of backcross inbred plant insect population groups showed continuous distribution,The result shows the resistance QTL qRPH-7-1 was located between Chr07₂5987777 and Chr07₂5976748,LOD is 2.5928,the contribution rate is9.1105%, The resistance QTL by male.?4? In this study, the QTL analysis of resistance ability for the population to brown planthopper were conducted in seedling and heading date satge, and two major different QTL were detected, they located in different chromosomes. the results implied that the gene associated with brown planthopper maybe different in in seedling and heading date satge, in other word, the resisitance mechanism to brown planthopper in seedling stage and heading date satge might be different. meanwhile, the detection of qBPH-12-1 and qRPH-7-1 has provide a good foundation for the cloning ang using of these QTLs.