Analysis of Resistance-related Proteins in Rice Against Brown Planthopper by Two-dimensional Electrophoresis

A recombinant inbred population (RI) was constructed from a cross between B5, an introgression. line from the wild rice Oryza officinalis Wall. ex Watt, and susceptible cultivar Minghui 63 ( O. sativa L.). The brown planthopper ( BPH) resistances of RI lines were evaluated. Based on bulked segregant analysis (BSA), two protein bulks were made by extracting proteins from equally mixed seedlings of extremely resistant and susceptible plants selected from the RI population, respectively. Two-dimensional electrophoresis was used to detect the changes of polypeptide pattern. Results showed that a protein P40 ( pI 6.3, Mw 40 kD) was significantly reduced or vanished after BPH infestation for 48 h in the susceptible bulk, while it remained uninfluenced in the resistant bulk. In connection with the physiological changes of the resistant and susceptible lines subjected to BPH sucking, we suppose that the protein P40 is related to the interaction responses of lice plants to BPH infestation.

Improving the resistance of the rice PTGMS line Feng39S by pyramiding blast,bacterial blight,and brown planthopper resistance genes

Knowledge of rice(Oryza sativa L.)genes and various DNA markers can be used in genomic breeding programs aimed at developing improved elite rice cultivars.We used an efficient genomic breeding approach to pyramid four resistance genes(Pi2,Xa23,Bph14,and Bph15)in the popular photoperiod-and thermosensitive genic male sterile(PTGMS)rice line Feng39S.We performed foreground selection for the target genes,followed by recombinant selection and background selection.This process reduced the sizes of the genomic segments harboring the target genes(566.8 kb for Pi2,1143.9 kb for Xa23,774.7 kb for Bph14,and 1574.9 kb for Bph15)and accelerated the recovery of the recurrent parent genome to proportions ranging from 98.77%to 99.16%,thus resulting in four near-isogenic lines.To assemble the four resistance genes in Feng39S,we performed a double-way cross combined with foreground and background selection to generate two improved lines of Feng39S(Pi2+Xa23+Bph14+Bph15)with a recurrent parent genome recovery of 98.98%.The two lines showed agronomic performance,grain quality,and fertility–sterility transition characteristics similar to those of the original Feng39S line.The newly developed PTGMS lines and corresponding hybrid combinations were resistant to various field blast isolates and seven representative isolates of bacterial blight.At the seedling stage,the lines also showed resistance against brown planthopper.This study provides an efficient and accurate genomic breeding approach for introducing desirable traits into PTGMS lines.

Breeding of Maintainer Line and Sterile Line Brown Planthopper Resistant Rice Using Marker-assisted Selection

Guangxi common wild rice variety brown planthopper highly resistant introgression line HS204 was taken as antigen donor material,hybridization,backcrossing,and molecular marker-assisted selection methods were adopted,to select maintainer line and sterile line materials,so as to provide excellent material foundation for resistance breeding of hybrid rice. Through the marker-assisted selection,it obtained 4 pieces of homozygous resistance gene maintainer line intermediate materials( 100B,101B,102B and 103B),and 2 pieces of resistant sterile line materials( 100A and 103A). All 10 combinations that have testcross with highly resistant sterile 100A showed higher level of brown planthopper resistance: 100A/R2586,100A/KR838,and 100A/KR527 had high resistance level,the others had low to intermediate resistance;100A/KR527,100A/R2586,100A/Minghui 63,100A/Fuhui 838 and 100A/Gui 99 combinations had yield per plant significantly higher than the control group( Teyou 7118),increasing by 14. 45%-49. 26%. The obtained resistant lines are expected to provide a better gene source for the breeding of resistant sterile lines of hybrid rice and the obtained resistant sterile lines can be directly used in the selection of three-line hybrid rice.