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To provide ready-to-use markers for background selection in markerassisted breeding of rice, we have extracted 840 hypervariable microsatellite markers (hvRMs) evenly distributed in the genome from 18 828 Class I simple sequence repeats. These hvRMs were grouped into bins of 5-Mb intervals with 5-8 bins depending on the chromosome length. In each bin, 10 hvRMs were selected based on their microsatellite repeat number and type. Of 840, a representative of 36 hvRMs were selected and its polymorphic information content (PIC) was estimated by amplifying 24 diverse rice cultivars. The findings revealed that hvRMs show high PIC values and more alleles when compared to the 25 randomly chosen microsatellite markers. The informative hvRMs developed for background selection across cultivars in this study along with the already established molecular markers tightly linked to the genes of agronomic value could be of value for the development of a ÔMAS kitÕ for speeding up the efforts of plant breeders for targeted crop improvement.

Rice is the most important staple food crop, and it feeds more than half of the world population. Brown planthopper (BPH) is a major insect pest of rice that causes 20–80% yield loss through direct and indirect damage. The identification and use of BPH resistance genes can efficiently manage BPH. A molecular marker-based genetic analysis of BPH resistance was carried out using 101 BC1F5 mapping population derived from a cross between a BPH-resistant indica variety Khazar and an elite BPH-susceptible line Huang–Huan–Zhan. The genetic analysis indicated the existence of Mendelian segregation for BPH resistance. A total of 702 high-quality polymorphic single nucleotide polymorphism (SNP) markers, genotypic data, and precisely estimated BPH scores were used for molecular mapping, which resulted in the identification of the BPH38(t) locus on the long arm of chromosome 1 between SNP markers 693,369 and id 10,112,165 of 496.2 kb in size with LOD of 20.53 and phenotypic variation explained of 35.91%. A total of 71 candidate genes were predicted in the detected locus. Among these candidate genes, LOC_Os01g37260 was found to belong to the FBXL class of F-box protein possessing the LRR domain, which is reported to be involved in biotic stress resistance. Furthermore, background analysis and phenotypic selection resulted in the identification of introgression lines (ILs) possessing at least 90% recurrent parent genome recovery and showing superior performance for several agro-morphological traits. The BPH resistance locus and ILs identified in the present study will be useful in marker-assisted BPH resistance breeding programs.Electronic supplementary materialThe online version of this article (10.1007/s10681-019-2506-2) contains supplementary material, which is available to authorized users.

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