title: Pyramiding and evaluation of three dominant brown planthopper resistance genes in the elite indica rice 9311 and its hybrids.
abstract: BACKGROUND
  Brown planthopper (BPH), Nilaparvata lugens Stål, is the most devastating insect pest in rice-producing areas. Three dominant BPH resistance genes (Bph14, Bph15, Bph18) were pyramided into elite indica rice 9311 and its hybrids using marker-assisted selection. Gene effectiveness was evaluated on the basis of seedling and adult rice resistance, honeydew weight and survival rate of BPH.
  
  
  RESULTS
  All three genes affected BPH growth and development and antibiotic factors, resulting in both seedling and adult resistance. Bph15 had the greatest effect on conferring resistance to BPH. The results showed an additive effect of pyramiding genes, the order of the gene effect being 14/15/18 ≥ 14/15 > 15/18 ≥ 15 > 14/18 ≥ 14 ≥ 18 > none. The pyramided or single-gene introgression hybrids showed greater resistance than conventional hybrids, although the heterozygous genotypes had weaker effects than the corresponding homozygous genotypes. Furthermore, field trial data demonstrated that yields of improved 9311 lines were higher than or similar to that of the control under natural field conditions. These improved versions can be immediately used in hybrid improvement and production.
  
  
  CONCLUSIONS
  Compared with controls, pyramided lines and hybrids with three genes showed the strongest resistance to BPH, without a yield decrease.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Crop Molecular Breeding, Huazhong Agricultural University, Wuhan, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Hu
authors.forename: Mingxing
authors.initials: M
authors.lastname: Cheng
authors.forename: Guanjun
authors.initials: G
authors.lastname: Gao
authors.forename: Qinglu
authors.initials: Q
authors.lastname: Zhang
authors.forename: Jinghua
authors.initials: J
authors.lastname: Xiao
authors.forename: Yuqing
authors.initials: Y
authors.lastname: He
mesh_terms: D000818:Animals; D060467:Disease Resistance; D005260:Female; D006430:Hemiptera / Q000502:physiology*; D007178:Inbreeding; D008297:Male; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000276:immunology / Q000469:parasitology*; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology / Q000469:parasitology*; D010940:Plant Proteins / Q000235:genetics / Q000276:immunology
chemical_list: D010940:Plant Proteins