Identification of Major Locus Bph35 Resistance to Brown Planthopper in Rice

Zhang Y, Qin G, Ma Q, Wei M, Yang X, Ma Z, Liang H, Liu C, Li Z, Liu F, Huang D, Li R

Rice Science, May 2020,  27(3):237-247

Abstract

An introgression line RBPH660, derived from wild rice Oryza rufipogon, showed stable resistance to brown planthopper (BPH). Segregation analysis indicated BPH resistance of RBPH660 was controlled by multiple genes/QTLs. By using the bulked segregant analysis (BSA)-seq method, two genomic regions harboring QTLs resistance to BPH were identified from 1.20 to 16.70 Mb on chromosome 4 and from 10.20 to 12.60 Mb on chromosome 9 in RBPH660, respectively. A major resistance locus, designated as Bph35 accounting for 51.27% of the phenotypic variation with a LOD score of 42.51, was mapped to the candidate region of chromosome 4 between InDel (insertion-deletion) markers PSM16 and R4M13. For fine mapping of Bph35, one simple sequence repeat and three newly developed InDel markers were used to screen the recombinants. Finally, the Bph35 locus was delimited in the region from 6.28 to 6.93 Mb and there were 18 predicted protein-encoding genes with a total of 114 non-synonymous single nucleotide polymorphism (SNP) variant sites between the resistant and susceptible parents. Out of these genes, Os04g0193950, encoding a putative NB-ARC (nucleotide- binding adaptor shared by APAF-1, R proteins and CED-4) and LRR (leucine-rich repeat) domain protein with nine non-synonymous SNP substitutions in its coding sequence regions, might be the candidate gene for Bph35. These findings would facilitate the map-based cloning of the Bph35 gene and development of resistant varieties against BPH in rice.

See https://www.sciencedirect.com/science/article/pii/S167263082030024X

Figure 3:

Mapped  of  a  major  resistance  locus  Bph35 to  BPH  on  chromosome 4. 

A, Bph35 was  detected  between  PSM16  and  R4M13  in  an  F2:3population  by  using  QTL  IciMapping  4.1,  accounted  for  51.27%  of the phenotypic variation with a LOD score of 42.51. PVE, Phenotypic variation explanation.

B, Further narrow down the genomic region of Bph35 to 650 kb by substitution mapping of recombinant plants.