In cultivated rice ( Oryza sativa L.), F-1 pollen sterility is controlled by at least 6 loci of the F, pollen sterility genes. To map S-b, one of loci, rice variety Taichung 65 (T65) carrying S-b(j)/S-b(j) and its nea...In cultivated rice ( Oryza sativa L.), F-1 pollen sterility is controlled by at least 6 loci of the F, pollen sterility genes. To map S-b, one of loci, rice variety Taichung 65 (T65) carrying S-b(j)/S-b(j) and its near-isogenic line TIST2 carrying S-b(i)/S-b(i) were used to develop the mapping population. One hundred and fifty-eight microsatellite markers were selected to survey T65 and TISL2. RM13 on chromosome 5 was found to be polymorphic between them. Cosegregation indicated that RM13 was closely linked with locus S-b. Eleven RFLP markers were selected on the corresponding region from the genetic map of Rice Genome Research Program (RGP) of Japan to convert into sequence-tagged site (STS) markers. Amplicon length polymorphism (ALP) was carried out, but none of them was found to be polymorphic between T65 and TISL2. Then PCR-based RFLP (PBR) was done using six 4-nucleotide recognizing restriction endonucleases. Polymorphism was detected when PCR products of R830STS and R2213SSTS were digested with Taq I. Genetic analysis indicated that the distance between locus S-b and markers, R830STS, RM13 and R2213SSTS were 3.3 cM (centi-Morgan), 5.2 cM and 5.5 cM, respectively. These PCR-based markers could be directly used in marker-assisted selection. The technical system combining genetic mapping and PCR-based marker-assisted selection will facilitate the development of molecular breeding.展开更多
The objectives of this study were to isolate and characterize microsatellites from a heat tolerant variety of snap bean (Phaseolus vulgaris L.) in order to generate polymorphic genetic markers linked to quantitative t...The objectives of this study were to isolate and characterize microsatellites from a heat tolerant variety of snap bean (Phaseolus vulgaris L.) in order to generate polymorphic genetic markers linked to quantitative trait loci for heat tolerance. A genomic library contained 400-800 bp inserts was constructed and screened for the presence of (GA/CT) n and (CA/GT) n repeats. The proportion of positive clones yielded estimated of 3.72×10 4 such dinucleotide repeats per genome, roughly comparable to the abundance reported in other eukaryotic genomes. Twenty_six positive clones were sequenced. In contrast to mammalian genomes, the (GA/CT) n motif was much more abundant than the (CA/GT) n motif in these clones. The (GA/CT) n repeats also showed longer average repeat length (mean n =10.4 versus 6.5), suggesting that they are better candidates for yielding polymorphic genetic markers in the snap bean genome.展开更多
Based on 61 specimens reared from leaf-mining larvae on Carmona microphylla in Guangdong, Dialectica geometra （Meyrick, 1916）, which represents the genus Dialectica Walsingham newly recorded from China, is described...Based on 61 specimens reared from leaf-mining larvae on Carmona microphylla in Guangdong, Dialectica geometra （Meyrick, 1916）, which represents the genus Dialectica Walsingham newly recorded from China, is described and illustrated, and its DNA barcode was cloned and registered. The specimens are deposited in Hunan Agricultural University, Changsha and Zhuhai Entry-Exit Inspection and Quarantine Bureau, Zhuhai, China （ZHCIQ）.展开更多
Segmental duplications on rice (Oryza sativa L.) chromosomes 8, 9, 11, and 12 were studied by examining the distributions of sequences resolved by 13 probes detecting multiple copies of DNA sequences. Four of the hyb...Segmental duplications on rice (Oryza sativa L.) chromosomes 8, 9, 11, and 12 were studied by examining the distributions of sequences resolved by 13 probes detecting multiple copies of DNA sequences. Four of the hybridization bands detected by a repetitive sequence probe, rTRS, were mapped to the ends of all the four chromosomes. Two or three of the bands detected by each of the other 12 probes were also mapped to different chromosomes. The bands detected by the same probe usually occurred in similar locations of different chromosomes. Loci detected by different DNA probes were often similarly arranged on different chromosomes. Chromosomes 8 and 9 showed colinearity of marker loci arrangement indicating a possible common origin. A segment on chromosome 9 was also very similar to the previously reported duplicated fragments on the ends of chromosomes 11 and 12 which were also detected in this study, indicating a likely common origin. Moreover, the various degrees of distributional similarity of the segments suggest a complex relationship among the chromosomes in the evolution of the rice genome. These results support the proposition that chromosome duplication and diversification may be a mechanism for the origin and evolution of the chromosomes in the rice genome.展开更多
LK783 was found to be a good fertility restorer for K-type male sterility of wheat (Triticum aestivum L.). RAPD and ISSR (inter-simple sequence repeat polymorphism) markers were employed to map the major restoring gen...LK783 was found to be a good fertility restorer for K-type male sterility of wheat (Triticum aestivum L.). RAPD and ISSR (inter-simple sequence repeat polymorphism) markers were employed to map the major restoring gene in LK783. Maintainer and restorer DNA pools were established using the extreme sterile and fertile plants among KJ5418A//911289/LK783 F 1 population, respectively. Four hundred and eighteen RAPD primers and 33 ISSR primers were used for screening polymorphisms between the two pools, and amplification bands using a RAPD primer of OPK18 and an ISSR primer of UBC-845 were found polymorphic between the two pools. Linkage analysis showed that OPK18 450 and UBC-845 800 were linked to the restoring gene in LK783. The distance between the restoring gene and OPK18 450 was (15.07±6.28) cM (centiMorgan), with the distance between the restoring gene and UBC-845 800 being (8.20±4.85) cM. The marker of UBC-845 800 was located on chromosome 1BS by amplifying nulli-tetrasomics and 1B ditelosomics of Chinese Spring with the primer of UBC-845, indicating that the restoring gene in LK783 was located on 1BS. The breeding for new fertility restorer lines of K-type cytoplasmic male sterility of wheat would be facilitated by using the two markers.展开更多
文摘In cultivated rice ( Oryza sativa L.), F-1 pollen sterility is controlled by at least 6 loci of the F, pollen sterility genes. To map S-b, one of loci, rice variety Taichung 65 (T65) carrying S-b(j)/S-b(j) and its near-isogenic line TIST2 carrying S-b(i)/S-b(i) were used to develop the mapping population. One hundred and fifty-eight microsatellite markers were selected to survey T65 and TISL2. RM13 on chromosome 5 was found to be polymorphic between them. Cosegregation indicated that RM13 was closely linked with locus S-b. Eleven RFLP markers were selected on the corresponding region from the genetic map of Rice Genome Research Program (RGP) of Japan to convert into sequence-tagged site (STS) markers. Amplicon length polymorphism (ALP) was carried out, but none of them was found to be polymorphic between T65 and TISL2. Then PCR-based RFLP (PBR) was done using six 4-nucleotide recognizing restriction endonucleases. Polymorphism was detected when PCR products of R830STS and R2213SSTS were digested with Taq I. Genetic analysis indicated that the distance between locus S-b and markers, R830STS, RM13 and R2213SSTS were 3.3 cM (centi-Morgan), 5.2 cM and 5.5 cM, respectively. These PCR-based markers could be directly used in marker-assisted selection. The technical system combining genetic mapping and PCR-based marker-assisted selection will facilitate the development of molecular breeding.
文摘The objectives of this study were to isolate and characterize microsatellites from a heat tolerant variety of snap bean (Phaseolus vulgaris L.) in order to generate polymorphic genetic markers linked to quantitative trait loci for heat tolerance. A genomic library contained 400-800 bp inserts was constructed and screened for the presence of (GA/CT) n and (CA/GT) n repeats. The proportion of positive clones yielded estimated of 3.72×10 4 such dinucleotide repeats per genome, roughly comparable to the abundance reported in other eukaryotic genomes. Twenty_six positive clones were sequenced. In contrast to mammalian genomes, the (GA/CT) n motif was much more abundant than the (CA/GT) n motif in these clones. The (GA/CT) n repeats also showed longer average repeat length (mean n =10.4 versus 6.5), suggesting that they are better candidates for yielding polymorphic genetic markers in the snap bean genome.
基金supported by General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China (2009IK277)
文摘Based on 61 specimens reared from leaf-mining larvae on Carmona microphylla in Guangdong, Dialectica geometra （Meyrick, 1916）, which represents the genus Dialectica Walsingham newly recorded from China, is described and illustrated, and its DNA barcode was cloned and registered. The specimens are deposited in Hunan Agricultural University, Changsha and Zhuhai Entry-Exit Inspection and Quarantine Bureau, Zhuhai, China （ZHCIQ）.
文摘Segmental duplications on rice (Oryza sativa L.) chromosomes 8, 9, 11, and 12 were studied by examining the distributions of sequences resolved by 13 probes detecting multiple copies of DNA sequences. Four of the hybridization bands detected by a repetitive sequence probe, rTRS, were mapped to the ends of all the four chromosomes. Two or three of the bands detected by each of the other 12 probes were also mapped to different chromosomes. The bands detected by the same probe usually occurred in similar locations of different chromosomes. Loci detected by different DNA probes were often similarly arranged on different chromosomes. Chromosomes 8 and 9 showed colinearity of marker loci arrangement indicating a possible common origin. A segment on chromosome 9 was also very similar to the previously reported duplicated fragments on the ends of chromosomes 11 and 12 which were also detected in this study, indicating a likely common origin. Moreover, the various degrees of distributional similarity of the segments suggest a complex relationship among the chromosomes in the evolution of the rice genome. These results support the proposition that chromosome duplication and diversification may be a mechanism for the origin and evolution of the chromosomes in the rice genome.
文摘LK783 was found to be a good fertility restorer for K-type male sterility of wheat (Triticum aestivum L.). RAPD and ISSR (inter-simple sequence repeat polymorphism) markers were employed to map the major restoring gene in LK783. Maintainer and restorer DNA pools were established using the extreme sterile and fertile plants among KJ5418A//911289/LK783 F 1 population, respectively. Four hundred and eighteen RAPD primers and 33 ISSR primers were used for screening polymorphisms between the two pools, and amplification bands using a RAPD primer of OPK18 and an ISSR primer of UBC-845 were found polymorphic between the two pools. Linkage analysis showed that OPK18 450 and UBC-845 800 were linked to the restoring gene in LK783. The distance between the restoring gene and OPK18 450 was (15.07±6.28) cM (centiMorgan), with the distance between the restoring gene and UBC-845 800 being (8.20±4.85) cM. The marker of UBC-845 800 was located on chromosome 1BS by amplifying nulli-tetrasomics and 1B ditelosomics of Chinese Spring with the primer of UBC-845, indicating that the restoring gene in LK783 was located on 1BS. The breeding for new fertility restorer lines of K-type cytoplasmic male sterility of wheat would be facilitated by using the two markers.
