A mapping population of 98 lines (backcross inbred lines, BILs) derived from a backcross of Nipponbare/Kasalath// Nipponbare was planted at two experimental sites, Nanjing and Nanchang, and treated with high and optim...A mapping population of 98 lines (backcross inbred lines, BILs) derived from a backcross of Nipponbare/Kasalath// Nipponbare was planted at two experimental sites, Nanjing and Nanchang, and treated with high and optimal temperature during grain filling, respectively. The grain weight heat susceptibility index [GWHSI= (grain weight at optimum temperature-grain weight at high temperature) / grain weight at optimum temperature × 100] was employed to evaluate the tolerance of rice to heat stress. A genetic linkage map with 245 RFLP markers and a mixed linear-model approach was used to detect quantitative trait loci (QTLs) and their main effects, epistatic interactions and QTL× environment interactions (Q×E). The threshold of LOD score=2.0 was used to detect the significance of association between marker and trait. A total of 3 QTLs controlling heat tolerance during grain filling were detected, on chromosomes 1, 4 and 7, with LOD scores of 8.16, 11.08 and 12.86, respectively, and they explained the phenotypic variance of 8.94, 17.25 and 13.50 %, correspondingly. The QTL located in the C1100-R1783 region of chromosome 4 showed no QTL× environment interaction and epistatic effect, suggesting that it could be stably expressed in different environments and genetic backgrounds, and thus it would be valuable in rice breeding for heat tolerance improvement. This QTL allele, derived from Kasalath reduced 3.31% of the grain weight loss under heat stress. One located between R1613-C970 on chromosome 1 and the other between C1226-R1440 on chromosome 7, with additive effect 2.38 and 2.92%, respectively. The tolerance alleles of both these QTLs were derived from Nipponbare. Both of these QTLs had significant QTL× environment interactions, and the latter was involved in epistatic interaction also. Eight pairs of epistatic effect QTLs were detected, one pair each on chromosomes 1,2,3, 5, 7, 8, 10 and 12. The results could be useful for elucidating the genetic mechanism of heat-tolerance and the development of new rice varieties with heat tolerance during grain filling phase.展开更多
Quantitative trait loci (QTL) controlling seed dormancy in rice were identified usingrecombinant inbred lines (RILs) population derived from the cross between a japonicavariety Kinmaze and an indica variety DV85. Seed...Quantitative trait loci (QTL) controlling seed dormancy in rice were identified usingrecombinant inbred lines (RILs) population derived from the cross between a japonicavariety Kinmaze and an indica variety DV85. Seeds of two parental cultivars and each RILwere harvested in 35d after heading. The germination percentage of these seeds at 30℃for 7 days were measured as the degree of seed dormancy. QTL analysis was performed withWindows QTL Cartographer 1.13a program by composite interval mapping. A total of four QTLfor seed dormancy were detected on chromosome 2 (two regions), 5 and 11, respectively.Phenotypic variation explained by each QTL ranged from 8.37 to 17.40%. Responses of suchloci to a dormancy-breaking treatment with dry heat were further detected. The resultsshowed that two alleles of qDOR-2-1 and qDOR-5 from DV85 as well as the allele of qDOR-11 from Kinmaze increased the seed dormancy, which seemed to be easily broken by dry heattreatment. Such loci of seed dormancy may be applied to rice genetic improvement. Theallele of qDOR-2-2 from DV85 increased the seed dormancy, which could not be broken bydry heat treatment.展开更多
Seed dormancy is one of the most important traits related to the rice grain quality and seeds application, because it is associated with pre-harvest sprouting, resulting in a downgrading of quality and severe limitati...Seed dormancy is one of the most important traits related to the rice grain quality and seeds application, because it is associated with pre-harvest sprouting, resulting in a downgrading of quality and severe limitations in end-use application. The recent development of DNA markers and linkage maps of rice has made possible mapping of individual genes associated with complex seed dormancy traits, analyzing the genetics effects of individual genes and genotype-by- environment interactions. Up to now, numerous quantitative trait loci (QTLs) associated with seed dormancy in rice have been identified and mapped in the molecular genetic map by different populations. In this review, we focus on the genetic base of seed dormancy in rice, especially compare QTLs controlling seed dormancy reported up to now, analyze the expression and stability of QTLs controlling seed dormancy, and discuss the present problems. Finally we show a new pathway to further research on seed dormancy.展开更多
The originally proposed by Grice in light of violation of Cooperative Principle,to analyze the characters’ utterances based on the data collected from a masterpiece-A Dream of Red Mansions.The result reals that chara...The originally proposed by Grice in light of violation of Cooperative Principle,to analyze the characters’ utterances based on the data collected from a masterpiece-A Dream of Red Mansions.The result reals that characters,in order to imply their underlying meaning or intentions such as saving-face,self-protection or flattery,deliberately flouting the four maxim-the maxim of Quality,the maxim of Quantity,the maxim of Relevance and the maxim of Manners and then from that it can be inferred the characters’ characteristics,the degree of relationship and their emotions in particular situation.展开更多
Background Genetic factors are believed to play a role in the individual susceptibility to chronic obstructive pulmonary disease (COPD). A single nucleotide polymorphism (SNP) of tumour necrosis factor-α (TNF-α) has...Background Genetic factors are believed to play a role in the individual susceptibility to chronic obstructive pulmonary disease (COPD). A single nucleotide polymorphism (SNP) of tumour necrosis factor-α (TNF-α) has been reported but inconsistent results may arise from different populations and phenotypes of COPD. There are only a few published studies of interleukin-13 (IL-13) SNPs on COPD. The SNPs of TNF-α and IL-13 have not been studied in the Chinese population. This research was conducted to study the frequencies of IL-13 gene promoter 1055 (IL-13-1055) and TNF-α gene-308 polymorphisms in the patients with COPD and to investigate the effect of those genetic polymorphisms on COPD in the Chinese population.Methods A cohort of COPD patients and age matched controls were recruited from an inpatient hospital service in Beijing. Venous blood was obtained and genomic DNA was extracted from peripheral blood monocytes using standard method. Genomic DNA was used as a template for amplification by polymerase chain reaction (PCR) to determine the polymorphism at -1055 in the IL-13 gene promoter region. PCR restriction fragment length polymorphism (RFLP) was used to determine polymorphisms in the TNF-α gene-308 position. The products were investigated by sequence analysis also. Results One hundred and eleven COPD patients and 97 controls were studied. Seventy-five cases were current smokers in COPD patients and 36 were current smokers in controls. The frequencies of TT genotype in the IL-13 gene promoter region were 11.7% (13/111) in the COPD group and 13.4% (13/97) in the controls (P=0.713). However, the OR value of TT genotype was significantly increased to 6.4 (95% CI 1.62-25.39) in the smokers with COPD. TT genotype was also positively related to family history of COPD, OR=7.7 (95% CI 1.37-43.80). The frequencies of A allele in the TNF-α gene were 5.9% in COPD and 3.1% in controls (P=0.131). The OR value of A allele was 5.0 (95% CI 1.011 to 25.059) in smokers with COPD. Conclusions There is no significant difference in the frequencies of the TT genotype of IL-13-1055 or the A allele of the TNF-α between Han Chinese patients with COPD versus control. Thus, it does not appear that theseSNPs are independent factors in COPD for Han nationality in (Beijing. However,)these SNPs may increase the risk of COPD among smokers.展开更多
Heterosis for yield and its component traits between chromosome segments from IR24, an indica variety, and the counterparts from 02428, a japonica rice, was inves- tigated by using a hybrid F1 population composed of 6...Heterosis for yield and its component traits between chromosome segments from IR24, an indica variety, and the counterparts from 02428, a japonica rice, was inves- tigated by using a hybrid F1 population composed of 63 com- binations between 02428 and IR24 chromosome segment substitution lines (CSSLs) with the genetic background of Asominori, a japonica variety. Significant differences in het- erosis for yield and yield-component traits were observed among the crosses. Analysis of graphical genotyping showed that 14 substituted segments were responsible for yield het- erosis. All of them were from all the 12 chromosomes of IR24 except chromosomes 8 and 10. Six segments at the intervals of RFLP markers, such as X132—G1340—R459, X48— C393A, R288—R1854, R2918—X52, X257—C1350 and R367 —X189-2—X24-2 on chromosomes 2, 3, 4, 11 and 12 respec- tively, had very significant heterosis for yield at the level of P ≤0.005 based on t-test, individually increasing the hybrid yield by more than 35% compared with the control cross “Asominori×02428”. Most of IR24 chromosome segments were found to have no significant hybrid effect for yield and yield-component traits, and one segment located at R2171 on chromosome 6 possessed significant negative effect with 27% of yield decrease. Advantages of using CSSLs in the heterosis studies were discussed and approaches of the partial and genome-wide exploitation of rice heterosis between indica and japonica by molecular marker-assisted selection were then proposed.展开更多
基金supported by the National High Technology Research ahd Development Program of China(2003AA207020,2003AA222131)
文摘A mapping population of 98 lines (backcross inbred lines, BILs) derived from a backcross of Nipponbare/Kasalath// Nipponbare was planted at two experimental sites, Nanjing and Nanchang, and treated with high and optimal temperature during grain filling, respectively. The grain weight heat susceptibility index [GWHSI= (grain weight at optimum temperature-grain weight at high temperature) / grain weight at optimum temperature × 100] was employed to evaluate the tolerance of rice to heat stress. A genetic linkage map with 245 RFLP markers and a mixed linear-model approach was used to detect quantitative trait loci (QTLs) and their main effects, epistatic interactions and QTL× environment interactions (Q×E). The threshold of LOD score=2.0 was used to detect the significance of association between marker and trait. A total of 3 QTLs controlling heat tolerance during grain filling were detected, on chromosomes 1, 4 and 7, with LOD scores of 8.16, 11.08 and 12.86, respectively, and they explained the phenotypic variance of 8.94, 17.25 and 13.50 %, correspondingly. The QTL located in the C1100-R1783 region of chromosome 4 showed no QTL× environment interaction and epistatic effect, suggesting that it could be stably expressed in different environments and genetic backgrounds, and thus it would be valuable in rice breeding for heat tolerance improvement. This QTL allele, derived from Kasalath reduced 3.31% of the grain weight loss under heat stress. One located between R1613-C970 on chromosome 1 and the other between C1226-R1440 on chromosome 7, with additive effect 2.38 and 2.92%, respectively. The tolerance alleles of both these QTLs were derived from Nipponbare. Both of these QTLs had significant QTL× environment interactions, and the latter was involved in epistatic interaction also. Eight pairs of epistatic effect QTLs were detected, one pair each on chromosomes 1,2,3, 5, 7, 8, 10 and 12. The results could be useful for elucidating the genetic mechanism of heat-tolerance and the development of new rice varieties with heat tolerance during grain filling phase.
基金supported by the National Nature Science Foundation of Jiangsu Province,China(BK2003415)Jiangsu Province Tackle Key Problem Foundation(BE2001305).
文摘Quantitative trait loci (QTL) controlling seed dormancy in rice were identified usingrecombinant inbred lines (RILs) population derived from the cross between a japonicavariety Kinmaze and an indica variety DV85. Seeds of two parental cultivars and each RILwere harvested in 35d after heading. The germination percentage of these seeds at 30℃for 7 days were measured as the degree of seed dormancy. QTL analysis was performed withWindows QTL Cartographer 1.13a program by composite interval mapping. A total of four QTLfor seed dormancy were detected on chromosome 2 (two regions), 5 and 11, respectively.Phenotypic variation explained by each QTL ranged from 8.37 to 17.40%. Responses of suchloci to a dormancy-breaking treatment with dry heat were further detected. The resultsshowed that two alleles of qDOR-2-1 and qDOR-5 from DV85 as well as the allele of qDOR-11 from Kinmaze increased the seed dormancy, which seemed to be easily broken by dry heattreatment. Such loci of seed dormancy may be applied to rice genetic improvement. Theallele of qDOR-2-2 from DV85 increased the seed dormancy, which could not be broken bydry heat treatment.
基金The work was supported in part by a grant from the National Natural Science F oundation of China(30471120)the Natural Science Foundation of Jiangsu Province,China(BK2003415).
文摘Seed dormancy is one of the most important traits related to the rice grain quality and seeds application, because it is associated with pre-harvest sprouting, resulting in a downgrading of quality and severe limitations in end-use application. The recent development of DNA markers and linkage maps of rice has made possible mapping of individual genes associated with complex seed dormancy traits, analyzing the genetics effects of individual genes and genotype-by- environment interactions. Up to now, numerous quantitative trait loci (QTLs) associated with seed dormancy in rice have been identified and mapped in the molecular genetic map by different populations. In this review, we focus on the genetic base of seed dormancy in rice, especially compare QTLs controlling seed dormancy reported up to now, analyze the expression and stability of QTLs controlling seed dormancy, and discuss the present problems. Finally we show a new pathway to further research on seed dormancy.
文摘The originally proposed by Grice in light of violation of Cooperative Principle,to analyze the characters’ utterances based on the data collected from a masterpiece-A Dream of Red Mansions.The result reals that characters,in order to imply their underlying meaning or intentions such as saving-face,self-protection or flattery,deliberately flouting the four maxim-the maxim of Quality,the maxim of Quantity,the maxim of Relevance and the maxim of Manners and then from that it can be inferred the characters’ characteristics,the degree of relationship and their emotions in particular situation.
文摘Background Genetic factors are believed to play a role in the individual susceptibility to chronic obstructive pulmonary disease (COPD). A single nucleotide polymorphism (SNP) of tumour necrosis factor-α (TNF-α) has been reported but inconsistent results may arise from different populations and phenotypes of COPD. There are only a few published studies of interleukin-13 (IL-13) SNPs on COPD. The SNPs of TNF-α and IL-13 have not been studied in the Chinese population. This research was conducted to study the frequencies of IL-13 gene promoter 1055 (IL-13-1055) and TNF-α gene-308 polymorphisms in the patients with COPD and to investigate the effect of those genetic polymorphisms on COPD in the Chinese population.Methods A cohort of COPD patients and age matched controls were recruited from an inpatient hospital service in Beijing. Venous blood was obtained and genomic DNA was extracted from peripheral blood monocytes using standard method. Genomic DNA was used as a template for amplification by polymerase chain reaction (PCR) to determine the polymorphism at -1055 in the IL-13 gene promoter region. PCR restriction fragment length polymorphism (RFLP) was used to determine polymorphisms in the TNF-α gene-308 position. The products were investigated by sequence analysis also. Results One hundred and eleven COPD patients and 97 controls were studied. Seventy-five cases were current smokers in COPD patients and 36 were current smokers in controls. The frequencies of TT genotype in the IL-13 gene promoter region were 11.7% (13/111) in the COPD group and 13.4% (13/97) in the controls (P=0.713). However, the OR value of TT genotype was significantly increased to 6.4 (95% CI 1.62-25.39) in the smokers with COPD. TT genotype was also positively related to family history of COPD, OR=7.7 (95% CI 1.37-43.80). The frequencies of A allele in the TNF-α gene were 5.9% in COPD and 3.1% in controls (P=0.131). The OR value of A allele was 5.0 (95% CI 1.011 to 25.059) in smokers with COPD. Conclusions There is no significant difference in the frequencies of the TT genotype of IL-13-1055 or the A allele of the TNF-α between Han Chinese patients with COPD versus control. Thus, it does not appear that theseSNPs are independent factors in COPD for Han nationality in (Beijing. However,)these SNPs may increase the risk of COPD among smokers.
基金This work was supported by the High Technology Research and Development Pro-gram of China(Grant Nos.2002AA207020 and 2001AA241024)the National Natural Science Foundation of China(Grant No.30370906).
文摘Heterosis for yield and its component traits between chromosome segments from IR24, an indica variety, and the counterparts from 02428, a japonica rice, was inves- tigated by using a hybrid F1 population composed of 63 com- binations between 02428 and IR24 chromosome segment substitution lines (CSSLs) with the genetic background of Asominori, a japonica variety. Significant differences in het- erosis for yield and yield-component traits were observed among the crosses. Analysis of graphical genotyping showed that 14 substituted segments were responsible for yield het- erosis. All of them were from all the 12 chromosomes of IR24 except chromosomes 8 and 10. Six segments at the intervals of RFLP markers, such as X132—G1340—R459, X48— C393A, R288—R1854, R2918—X52, X257—C1350 and R367 —X189-2—X24-2 on chromosomes 2, 3, 4, 11 and 12 respec- tively, had very significant heterosis for yield at the level of P ≤0.005 based on t-test, individually increasing the hybrid yield by more than 35% compared with the control cross “Asominori×02428”. Most of IR24 chromosome segments were found to have no significant hybrid effect for yield and yield-component traits, and one segment located at R2171 on chromosome 6 possessed significant negative effect with 27% of yield decrease. Advantages of using CSSLs in the heterosis studies were discussed and approaches of the partial and genome-wide exploitation of rice heterosis between indica and japonica by molecular marker-assisted selection were then proposed.
