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 optima...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
Rice (Oryza sativa L. ) is one of the model plants for genomics research. As the raising offunctional rice breeding for special usage, glutelin mutants play a more and more important role in the func-tional rice breed...Rice (Oryza sativa L. ) is one of the model plants for genomics research. As the raising offunctional rice breeding for special usage, glutelin mutants play a more and more important role in the func-tional rice breeding as well as eukaryotic gene expression and regulation research materials. For example, therice cultivar special for the patients suffering from kidney disease and diabetes could be developed from the riceglutelin mutants. In this paper, current researches on characterization, mutation mechanism and breeding us-age of various rice glutelin mutants, especially the low glutelin content cultivars, were all discussed with per-spectives on the trends of the glutelin mutant researches in the era of post-genomics.展开更多
Amylose content is a key determinant of eating quality of rice. With the characteristics offluffy texture, glossy appearance when cooked, remaining soft when cooled and excellentpuffing ability, the low-amylose rice w...Amylose content is a key determinant of eating quality of rice. With the characteristics offluffy texture, glossy appearance when cooked, remaining soft when cooled and excellentpuffing ability, the low-amylose rice with amylose content 5-15% could be served as not onlycooked rice directly, but also good material for convenience, mixed rice and puffing foods.Current status on characterization, inheritance, molecular mechanism and breeding of low-amylose content rice was reviewed in this paper, strategy of related researches in the era ofglymics was mainly discussed furthermore. The future research should focus on screening andenhancing the germplasm, further elucidating the molecular mechanism on mutation of lowamylose content, utilizing the genes independent of Wx on low-amylose content rice breedingprogram, and developing high quality functional rice cultivars for special usage throughpyramiding low amylose gene and other special quality genes.展开更多
The performance and inheritance of 7 quality traits were studied using F2 rice grain derived from 8×8 diallel crossing made by employing 8 parents of different ecological japonica rice types. Differences in each ...The performance and inheritance of 7 quality traits were studied using F2 rice grain derived from 8×8 diallel crossing made by employing 8 parents of different ecological japonica rice types. Differences in each trait among 8 parents were not obvious, but in F2 generation, transgressive phenomena were found in all the traits studied, indicating that the genes controlling these traits among parents were segregated. The inheritance of grain width, grain weight, chalkiness score (CS), gelatinization temperature (GT) and gel consistency (GC) were suitable to additive-dominant model, and dominant effect contributed mainly for the 5 traits. The inheritance of grain length (GL) and amylose content (AC) did not fit into additive-dominant model, existing epistatic interactions. Dominant genes for grain width and grain weight had the efficiency of decreasing effect, and dominant genes for CS, GT and GC had the efficiency of enhancing effect. Koshihikari contained more recessive genes for gelatinization temperature than other varieties. Zhendao 88 had more dominant genes in grain width and grain weight than other varieties.Xiushui 04 possessed more dominant genes for GL and GC, and more recessive genes for CS than other varieties.展开更多
Allelic variation and genetic diversity at HMW glutenin subunits loci, Glu-A1, Glu-B1and Glu-D1 were investigated in 64 accessions of three unique wheats of western Chinausing sodium dodecyl sulphate polyacrylamide ge...Allelic variation and genetic diversity at HMW glutenin subunits loci, Glu-A1, Glu-B1and Glu-D1 were investigated in 64 accessions of three unique wheats of western Chinausing sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Two HMWglutenin patterns (i.e., null, 7+8, 2+12 and null, 7, 2+12) in 34 Yunnan wheataccessions, 3 HMW glutenin patterns (i.e., null, 7+8, 2+12; null, 6+8, 2+12 andnull, 7+8, 2) in 24 Tibetan accessions and 1 HMW glutenin pattern (null, 7, 2+12) in6 Xinjiang wheat accessions were found. The Tibetan accession TB18 was found to be witha rare subunit 2 encoded by Glu-D1. A total of 4 (i.e., Glu-A1c, Glu-B1a, Glu-B1b andGlu-D1a), 5 (i.e., Glu-A1c, Glu-B1d, Glu-B1b, Glu-D1a and Glu-D1) and 3 alleles (i.e.,Glu-A1c, Glu-B1a and Glu-D1a) at Glu-1 locus were identified among Yunnan, Tibetan andXinjiang unique wheat accessions, respectively. For Yunnan wheat, Tibetan wheat andXinjiang wheat, the Neis mean genetic variation indexes were 0.1574, 0.1366 and 0,respectively, which might indicate the higher genetic diversity at HMW glutenin subunitsloci of Yunnan and Tibetan wheat accessions as compared to that of Xinjiang wheataccessions. Among the three genomes of hexaploid wheats of western China, the highestNeis genetic variation index was appeared in B genome with the mean value of 0.2674,while the indexes for genomes A and D were 0 and 0.0270, respectively. It might bereasonable to indicate that Glu-B1 showed the highest, Glu-D1 the intermediate and Glu-A1 always the lowest genetic diversity.展开更多
With assistance of chromosome C-banding and genomic in situ hybridization (GISH) combinedwith meiotic analysis, five germplasms with homozygous wheat-Th. bessarabicum chromosometranslocations were developed and identi...With assistance of chromosome C-banding and genomic in situ hybridization (GISH) combinedwith meiotic analysis, five germplasms with homozygous wheat-Th. bessarabicum chromosometranslocations were developed and identified among BC1F5 progenies of the cross betweenT. aestivum cv. Chinese Spring and Chinese Spring-Th. bessarabicum amphiploid. Theselines included Tj01 and Tj02 (2n=44) containing a pair of wheat-Th. bessarabicumtranslocation chromosomes besides a pair of added Th. bessarabicum chromosomes, Tj03(2n=44) with a pair of added interspecific translocation chromosomes, Tj04 (2n=44)containing a pair of interspecific translocation chromosomes besides an added pair ofTh. bessarabicum chromosome arms and Tj05 (2n=46) containing a pair of interspecifictranslocation chromosomes besides two pairs of added intact alien chromosomes. Thebreakpoints of all the translocations were found to be not around centromere. Meanwhile,all the lines showed normal plant growth, development and fertility, while the translocationchromosomes transmitted regularly. The obtained translocations might be of use fortransferring elite genes from Th. bessarabicum into wheat.展开更多
Grh2, a green rice leafhopper resistant gene from an indica cultivar DV85, was located onchromosome 11, and two RFLP markers C189 and G1465 were found to be linked to this gene. In order totransfer Grh2 into Taichung6...Grh2, a green rice leafhopper resistant gene from an indica cultivar DV85, was located onchromosome 11, and two RFLP markers C189 and G1465 were found to be linked to this gene. In order totransfer Grh2 into Taichung65, a japonica cultivar with elite characters, backcross method with Taichung65as the recurrent parent was used and the two RFLP markers were converted into CAPS markers for marker as-sisted selection (MAS). In the BC6F3 population, both phenotypic evaluation and MAS were conducted toscreen the resistant plants with Taichung65 background. The linkage distance between CAPS markers andGrh2 was calculated and the efficiency of MAS was analyzed.展开更多
The investigation of rice varieties stability for amylose content (AC), gelatinization temperature (GT) and protein content (PC) was carried out using additive main effects and multiplicative interaction (AMMI) model ...The investigation of rice varieties stability for amylose content (AC), gelatinization temperature (GT) and protein content (PC) was carried out using additive main effects and multiplicative interaction (AMMI) model in three locations and two years. Eighteen tested varieties were further clustered and evaluated based on the phenotypic values of three quality traits and their Di values from the AMMI analysis. The results showed that the genotype by environment interactions, the differences of phenotype and stability of AC, GT and PC among different genotypes and environments were all significant at 1% level. Also, only one variety, W002, had high stability for all the three quality traits. Additionally, in consideration with the phenotype of AC, GT and PC, and their stability in rice varieties, etc., four rice varieties, W002, Zaofeng 9, Guangling Xiangjing and Nanjing16, could be also applied as breeding parents to improve eating quality and stability of rice.展开更多
Quantitative trait loci (QTLs) controlling palatability in rice were identified using a set of 98 backcross inbred lines (BILs) population derived from a cross between a japonica variety Nipponbare and an indica varie...Quantitative trait loci (QTLs) controlling palatability in rice were identified using a set of 98 backcross inbred lines (BILs) population derived from a cross between a japonica variety Nipponbare and an indica variety Kasalath. The palatability scores of the population measured by RQ1/Plus Rice Analyzer, showed a continuous and transgressive segregative distribution with a range from 66 to 92. Four putative QTLs for palatability, qPAL-5, qPAL-7, qPAL-8a and qPAL-8b, were detected on chromosome 5, 7 and 8, and they accounted 7.83, 7.03, 11.58 and 7.19% of the total phenotypic variation, respectively. Three alleles qPAL-5, qPAL-7 and qPAL-8b from Kasalath increased the palatability score, whereas only one Nipponbare allele qPAL-8a increased the score. Eight transgressive lines in palatability were selected to make a comparison between phenotypic and genotypic classes. The result explained the possibility of positive QTLs pyramiding through marker-assisted selection of highly palatable rice.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
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
Reverse transcription-polymerase chain reaction (RT-PCR) was performed to isolate a cDNA clone using specific primers designed based on the barley (Hordeum vulgare L.) Mlo gene cDNA sequence.A full-length cDNA encodin...Reverse transcription-polymerase chain reaction (RT-PCR) was performed to isolate a cDNA clone using specific primers designed based on the barley (Hordeum vulgare L.) Mlo gene cDNA sequence.A full-length cDNA encoding an Mlo-like protein was isolated and characterized in a Triticum aestivum L.-Haynaldia villosa L. 6VS/6AL translocation line. The putative protein consists of 534 amino acid residues,which contain a nuclear localization motif (NLS), nine casein kinase Ⅱ motifs (S/T-X-X-D/E) and seven protein kinase C motifs (S/T-X-R/K). It is highly homologous to other plant Mlo proteins. Thus, this clone was designated as Ta-Mlo (GenBank accession No. AF384144). Northern blotting analysis showed that the transcription of Ta-Mlo was enhanced slightly by Blumeria graminis (DC) EO Speer f. sp. tritici. Western blotting analysis showed that the protein expression product of the Ta-Mlo gene in wheat seedling leaves is a membrane-bound protein. The protein could be induced by B. graminis. Southern blotting analysis indicated that there is one copy of the Ta-Mlo gene in each wheat genome. Ta-Mlo was localized on specific chromosomal regions of 2AL, 2BL, and 2DL in wheat.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The project was supported by the National Science Foundation of China(30170570)the 948”Project of the Ministry of Agriculture of China(201002A)+1 种基金Jiangsu Science Foundation(BJ2000019)Rice Development Foundation of China(0003102).
文摘Rice (Oryza sativa L. ) is one of the model plants for genomics research. As the raising offunctional rice breeding for special usage, glutelin mutants play a more and more important role in the func-tional rice breeding as well as eukaryotic gene expression and regulation research materials. For example, therice cultivar special for the patients suffering from kidney disease and diabetes could be developed from the riceglutelin mutants. In this paper, current researches on characterization, mutation mechanism and breeding us-age of various rice glutelin mutants, especially the low glutelin content cultivars, were all discussed with per-spectives on the trends of the glutelin mutant researches in the era of post-genomics.
基金supported by the National Natural Science Foundation of China(30270811).
文摘Amylose content is a key determinant of eating quality of rice. With the characteristics offluffy texture, glossy appearance when cooked, remaining soft when cooled and excellentpuffing ability, the low-amylose rice with amylose content 5-15% could be served as not onlycooked rice directly, but also good material for convenience, mixed rice and puffing foods.Current status on characterization, inheritance, molecular mechanism and breeding of low-amylose content rice was reviewed in this paper, strategy of related researches in the era ofglymics was mainly discussed furthermore. The future research should focus on screening andenhancing the germplasm, further elucidating the molecular mechanism on mutation of lowamylose content, utilizing the genes independent of Wx on low-amylose content rice breedingprogram, and developing high quality functional rice cultivars for special usage throughpyramiding low amylose gene and other special quality genes.
文摘The performance and inheritance of 7 quality traits were studied using F2 rice grain derived from 8×8 diallel crossing made by employing 8 parents of different ecological japonica rice types. Differences in each trait among 8 parents were not obvious, but in F2 generation, transgressive phenomena were found in all the traits studied, indicating that the genes controlling these traits among parents were segregated. The inheritance of grain width, grain weight, chalkiness score (CS), gelatinization temperature (GT) and gel consistency (GC) were suitable to additive-dominant model, and dominant effect contributed mainly for the 5 traits. The inheritance of grain length (GL) and amylose content (AC) did not fit into additive-dominant model, existing epistatic interactions. Dominant genes for grain width and grain weight had the efficiency of decreasing effect, and dominant genes for CS, GT and GC had the efficiency of enhancing effect. Koshihikari contained more recessive genes for gelatinization temperature than other varieties. Zhendao 88 had more dominant genes in grain width and grain weight than other varieties.Xiushui 04 possessed more dominant genes for GL and GC, and more recessive genes for CS than other varieties.
文摘Allelic variation and genetic diversity at HMW glutenin subunits loci, Glu-A1, Glu-B1and Glu-D1 were investigated in 64 accessions of three unique wheats of western Chinausing sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Two HMWglutenin patterns (i.e., null, 7+8, 2+12 and null, 7, 2+12) in 34 Yunnan wheataccessions, 3 HMW glutenin patterns (i.e., null, 7+8, 2+12; null, 6+8, 2+12 andnull, 7+8, 2) in 24 Tibetan accessions and 1 HMW glutenin pattern (null, 7, 2+12) in6 Xinjiang wheat accessions were found. The Tibetan accession TB18 was found to be witha rare subunit 2 encoded by Glu-D1. A total of 4 (i.e., Glu-A1c, Glu-B1a, Glu-B1b andGlu-D1a), 5 (i.e., Glu-A1c, Glu-B1d, Glu-B1b, Glu-D1a and Glu-D1) and 3 alleles (i.e.,Glu-A1c, Glu-B1a and Glu-D1a) at Glu-1 locus were identified among Yunnan, Tibetan andXinjiang unique wheat accessions, respectively. For Yunnan wheat, Tibetan wheat andXinjiang wheat, the Neis mean genetic variation indexes were 0.1574, 0.1366 and 0,respectively, which might indicate the higher genetic diversity at HMW glutenin subunitsloci of Yunnan and Tibetan wheat accessions as compared to that of Xinjiang wheataccessions. Among the three genomes of hexaploid wheats of western China, the highestNeis genetic variation index was appeared in B genome with the mean value of 0.2674,while the indexes for genomes A and D were 0 and 0.0270, respectively. It might bereasonable to indicate that Glu-B1 showed the highest, Glu-D1 the intermediate and Glu-A1 always the lowest genetic diversity.
文摘With assistance of chromosome C-banding and genomic in situ hybridization (GISH) combinedwith meiotic analysis, five germplasms with homozygous wheat-Th. bessarabicum chromosometranslocations were developed and identified among BC1F5 progenies of the cross betweenT. aestivum cv. Chinese Spring and Chinese Spring-Th. bessarabicum amphiploid. Theselines included Tj01 and Tj02 (2n=44) containing a pair of wheat-Th. bessarabicumtranslocation chromosomes besides a pair of added Th. bessarabicum chromosomes, Tj03(2n=44) with a pair of added interspecific translocation chromosomes, Tj04 (2n=44)containing a pair of interspecific translocation chromosomes besides an added pair ofTh. bessarabicum chromosome arms and Tj05 (2n=46) containing a pair of interspecifictranslocation chromosomes besides two pairs of added intact alien chromosomes. Thebreakpoints of all the translocations were found to be not around centromere. Meanwhile,all the lines showed normal plant growth, development and fertility, while the translocationchromosomes transmitted regularly. The obtained translocations might be of use fortransferring elite genes from Th. bessarabicum into wheat.
基金This work was conducted in Kyushu University,Japan by the first author during his visiting research supported by China Scholarship Counsel(CSC),the“948”Project of the Ministry of Agriculture of Chinathe Program for Outstanding Teachers by the Ministry of Education of China.
文摘Grh2, a green rice leafhopper resistant gene from an indica cultivar DV85, was located onchromosome 11, and two RFLP markers C189 and G1465 were found to be linked to this gene. In order totransfer Grh2 into Taichung65, a japonica cultivar with elite characters, backcross method with Taichung65as the recurrent parent was used and the two RFLP markers were converted into CAPS markers for marker as-sisted selection (MAS). In the BC6F3 population, both phenotypic evaluation and MAS were conducted toscreen the resistant plants with Taichung65 background. The linkage distance between CAPS markers andGrh2 was calculated and the efficiency of MAS was analyzed.
基金The project was supported by the National 863 Program(2003AA222131 and 2003AA207020)the National Natural Science Foundation of China(30270811)+1 种基金the National Science and Technology Achievements Spreading Program(02EFN213200232)Jiangsu Science and Technology Development Program,China(BE 2001305).
文摘The investigation of rice varieties stability for amylose content (AC), gelatinization temperature (GT) and protein content (PC) was carried out using additive main effects and multiplicative interaction (AMMI) model in three locations and two years. Eighteen tested varieties were further clustered and evaluated based on the phenotypic values of three quality traits and their Di values from the AMMI analysis. The results showed that the genotype by environment interactions, the differences of phenotype and stability of AC, GT and PC among different genotypes and environments were all significant at 1% level. Also, only one variety, W002, had high stability for all the three quality traits. Additionally, in consideration with the phenotype of AC, GT and PC, and their stability in rice varieties, etc., four rice varieties, W002, Zaofeng 9, Guangling Xiangjing and Nanjing16, could be also applied as breeding parents to improve eating quality and stability of rice.
基金supported by National Natural Science Foundation(303708685)Zhejiang Natural Science Foundation(R304482,ZA0106)National High Technology Research and Development Program of China(2002AA207002,2000AA222131).
文摘Quantitative trait loci (QTLs) controlling palatability in rice were identified using a set of 98 backcross inbred lines (BILs) population derived from a cross between a japonica variety Nipponbare and an indica variety Kasalath. The palatability scores of the population measured by RQ1/Plus Rice Analyzer, showed a continuous and transgressive segregative distribution with a range from 66 to 92. Four putative QTLs for palatability, qPAL-5, qPAL-7, qPAL-8a and qPAL-8b, were detected on chromosome 5, 7 and 8, and they accounted 7.83, 7.03, 11.58 and 7.19% of the total phenotypic variation, respectively. Three alleles qPAL-5, qPAL-7 and qPAL-8b from Kasalath increased the palatability score, whereas only one Nipponbare allele qPAL-8a increased the score. Eight transgressive lines in palatability were selected to make a comparison between phenotypic and genotypic classes. The result explained the possibility of positive QTLs pyramiding through marker-assisted selection of highly palatable rice.
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.
文摘Reverse transcription-polymerase chain reaction (RT-PCR) was performed to isolate a cDNA clone using specific primers designed based on the barley (Hordeum vulgare L.) Mlo gene cDNA sequence.A full-length cDNA encoding an Mlo-like protein was isolated and characterized in a Triticum aestivum L.-Haynaldia villosa L. 6VS/6AL translocation line. The putative protein consists of 534 amino acid residues,which contain a nuclear localization motif (NLS), nine casein kinase Ⅱ motifs (S/T-X-X-D/E) and seven protein kinase C motifs (S/T-X-R/K). It is highly homologous to other plant Mlo proteins. Thus, this clone was designated as Ta-Mlo (GenBank accession No. AF384144). Northern blotting analysis showed that the transcription of Ta-Mlo was enhanced slightly by Blumeria graminis (DC) EO Speer f. sp. tritici. Western blotting analysis showed that the protein expression product of the Ta-Mlo gene in wheat seedling leaves is a membrane-bound protein. The protein could be induced by B. graminis. Southern blotting analysis indicated that there is one copy of the Ta-Mlo gene in each wheat genome. Ta-Mlo was localized on specific chromosomal regions of 2AL, 2BL, and 2DL in wheat.
