High-resolution mapping of two rice brown planthopper resistance genes, Bph20(t) and Bph21(t), originating from Oryza minuta.
Brown planthopper (BPH) is one of the most destructive insect pests of rice. Wild species of rice are a valuable source of resistance genes for developing resistant cultivars. A molecular marker-based genetic analysis of BPH resistance was conducted using an F(2) population derived from a cross between an introgression line, 'IR71033-121-15', from Oryza minuta (Accession number 101141) and a susceptible Korean japonica variety, 'Junambyeo'. Resistance to BPH (biotype 1) was evaluated using 190 F(3) families. Two major quantitative trait loci (QTLs) and two significant digenic epistatic interactions between marker intervals were identified for BPH resistance. One QTL was mapped to 193.4-kb region located on the short arm of chromosome 4, and the other QTL was mapped to a 194.0-kb region on the long arm of chromosome 12. The two QTLs additively increased the resistance to BPH. Markers co-segregating with the two resistance QTLs were developed at each locus. Comparing the physical map positions of the two QTLs with previously reported BPH resistance genes, we conclude that these major QTLs are new BPH resistance loci and have designated them as Bph20(t) on chromosome 4 and Bph21(t) on chromosome 12. This is the first report of BPH resistance genes from the wild species O. minuta. These two new genes and markers reported here will be useful to rice breeding programs interested in new sources of BPH resistance.
Rahman
Md Lutfor
ML
Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.
Jiang
Wenzhu
W
Chu
Sang Ho
SH
Qiao
Yongli
Y
Ham
Tae-Ho
TH
Woo
Mi-Ok
MO
Lee
Joohyun
J
Khanam
M Sakina
MS
Chin
Joong-Hyoun
JH
Jeung
Ji-Ung
JU
Brar
D S
DS
Jena
K K
KK
Koh
Hee-Jong
HJ
D000818:Animals; D032461:Chromosomes, Plant; D003433:Crosses, Genetic; D004843:Epistasis, Genetic; D017343:Genes, Plant; D005819:Genetic Markers; D006430:Hemiptera / Q000235:genetics*; D012275:Oryza / Q000235:genetics*; D020161:Physical Chromosome Mapping; D040641:Quantitative Trait Loci
D005819:Genetic Markers