Faba bean （Vicia faba L.）, one of the most important legumes in the world, evolved different types of cultivars due to its partial cross-pollination. The development of simple sequence repeat （SSR） markers from ex...Faba bean （Vicia faba L.）, one of the most important legumes in the world, evolved different types of cultivars due to its partial cross-pollination. The development of simple sequence repeat （SSR） markers from expressed sequence tags （EST） provided a useful tool for investigation of its genetic diversity. The purpose of the present study was to investigate the genetic diversity of faba bean from China and Europe using EST-SSR markers. 5 031 faba bean ESTs from the NCBI database were downloaded and assembled into 1 148 unigenes. A total of 107 microsatellites in 96 unigenes were identified, indicating that merely 8.36% of sequences contained SSRs. The most abundant SSR within faba bean was tri-nucleotide repeat motif, and among all the tri-nucleotide repeats, the motif AAG/CTT was the most abundant type. Based on these results, 11 EST-SSR markers were used to assess the genetic diversity of 29 faba bean cultivars from China and Europe with two to three alleles per locus. The polymorphism information content value ranged from 0.0644 to 0.4278 with an average of 0.2919. Principal coordinate analysis （PCA） and phylogenetic clustering based on these 11 EST-SSR markers distinguished these cultivars into different groups. The results indicated that faba bean in China had a narrow genetic basis, and the additional sources of genetic cultivars/accessions should be introduced to enhance the genetic variability. The results of this study proved that the EST-SSR marker is very effective in evaluation of faba bean germplasm.展开更多
Fifteen expressed sequence tag (EST)-derived simple sequence repeats (EST-SSRs) were used to investigate genetic diversity in 139 plants obtained from seeds of 35 watermelon accessions collected from all the geographi...Fifteen expressed sequence tag (EST)-derived simple sequence repeats (EST-SSRs) were used to investigate genetic diversity in 139 plants obtained from seeds of 35 watermelon accessions collected from all the geographical provinces of Zimbabwe. In addition, 15 plants representing three commercial varieties developed in the United States (USA) were analyzed for comparison. A total of 65 alleles were detected among all the watermelon accessions. For the 13 polymorphic EST-SSR loci, number of alleles per locus varied from 2 to 13, with an average of 5 alleles per locus. Values for the polymorphic information content increased as the number of alleles increased, and varied from 0.15 to 0.77 with an average of 0.54 suggesting sufficient discriminatory power. Both cluster analysis and principal coordinate analysis (PCA) produced two major clusters;one with the 22 cow-melon accessions and the other with the 16 sweet watermelon accessions. Within the sweet watermelon group, two distinct sub-clusters formed, one of which contained only two of the commercial varieties from USA. Partitioning of genetic variation in the Zimbabwean material using analysis of molecular variation (AMOVA) revealed that 64% of the total variation resides between the two major forms, i.e. sweet watermelons and cow-melons, 28% between accessions within forms and 8% within accessions. The EST-SSR markers revealed a somewhat higher diversity in sweet watermelon accessions compared to that of cow-melons. This finding is contrary to previous reports using other markers (genomic SSR loci or RAPD) and/or a plant material that is likely to have experienced more stringent selection procedures compared to the landraces analyzed in our study.展开更多
In this study, 27 pairs of EST-SSR primers were employed to analyze the genetic diversity and genetic relationship of 100 wild tea plant germplasm re- sources and 22 cultivars, according to the results, a total of 88 ...In this study, 27 pairs of EST-SSR primers were employed to analyze the genetic diversity and genetic relationship of 100 wild tea plant germplasm re- sources and 22 cultivars, according to the results, a total of 88 polymorphic bands were amplified with 27 pairs of primers; the variation of effective alleles accounted for 69.01% ; a total of 183 genotypes were detected, with a variation range of 4 -11 ; averagely 6.78 genotypes were amplified with each primer pair; Shannon index （I） of 27 primer pairs ranged from 0.32 to I. 35, with an average of 0.88 ; the observed heterozygosity （0.52） was basically consistent with the expected het- erozygosity （0.52） ; the average polymorphism heterozygosity was 0.48, which was very close to 0.50 ; the average Nei＇s index was 0.51, which was higher than 0. 50 ; the average polymorphism information content （PIC） was 0.52, which was higher than 0.50, indicating high genetic diversity among wild tea germplasm resources in Yuunan Province. According to the clustering results, based on geographical origins and genetic backgrounds, 122 materials were clustered into 14 categories. Dendrogram based on Nei＇s genetic distance revealed complex genetic relationships among wild tea germplasm resources in Yunnan Province. This study provided certain reference for subsequent preservation, development and research of wild tea germplasm resources in China.展开更多
EST sequences of Mentha piperita available in the public domain(NCBI) were exploited to develop SSR markers. A total of 1316 ESTs were assembled into 155 contigs and 653 singletons and of these, 110 sequences were fou...EST sequences of Mentha piperita available in the public domain(NCBI) were exploited to develop SSR markers. A total of 1316 ESTs were assembled into 155 contigs and 653 singletons and of these, 110 sequences were found to contain 130 SSRs, with a frequency of1 SSR/3.4 kb. Dinucleotide repeat SSRs were most frequent(72.3%) with the AG/CT(43.8%)repeat motif followed by AT/AT(16.2%). Primers were successfully designed for 68SSR-containing sequences(62.0%). The 68 primers amplified 13 accessions of M. piperita and 54 produced clear amplicons of the expected size. Of these 54, 33(61%) were found to be polymorphic among M. piperita accessions, showing from 2 to 4 alleles with an average of2.33 alleles/SSR, and the polymorphic information content(PIC) value varied between 0.13 and 0.51(average 0.25). All the amplified SSRs showed transferability among four different species of Mentha, with a highest in Mentha arvensis(87.0%) and minimum in Mentha citrata(37.0%). The newly developed SSRs markers were found to be useful for diversity analysis, as they successfully differentiated among species and accessions of Mentha.展开更多
Cryptromeria fortunei is one of the main forest plantation species in the subtropical high altitude areas in China. In this paper we collected 49 C. fortunei germplasm resources and provides a study of the utility of ...Cryptromeria fortunei is one of the main forest plantation species in the subtropical high altitude areas in China. In this paper we collected 49 C. fortunei germplasm resources and provides a study of the utility of freely available C. japonica EST resources for the development of markers necessary for genetic diversity analyses of C. fortunei. By screening 24,299 EST sequences from C. japonica with SSR Finder, we identified 2384 ESTs car- rying 2783 SSR motifs. We successfully obtained 364 （15 %） primers from 2419 putative SSR loci. Of the 80 candidate SSR markers tested, 70 （87.5 %） yielded stable and clear PCR products. With those primers, the genetic diversity of 49 C. fortunei we collected was studied. The results showed that 18 primers yield polymorphism within these accessions. These 18 primers generated 48 scorable SSR loci and the average number of polymorphic SSR loci per primer was 2.7. The PIC value varied from 0.375 to 0.8101, with the average of 0.4780. The Shannon index is 0.5718, and the value of the observed number of alleles and effective number of alleles are 1.9167 and 1.7289, respectively. The genetic coefficient of these 49 accessions varied from 0.28 to 0.87. According to the genetic dis- tances, a cluster tree was constructed. At genetic coefficient of 0.60, these 49 accessions can group into 3： group I contains only FJ-laizhou accession, and group II contains 2accessions from FJ-layang, and the other one group con- tains mixed accessions. At genetic coefficient of 0.68, the former group II was constructed into 7 subgroups, with the first 3 subgroups contain 16 accessions in which 11 （69 %） are from Fujian province, and the later 4 subgroup contain 31 accessions in which 20 （65 %） were from Zhejiang province.展开更多
基金supported by the Zhejiang Provincial Science and Technology Program, China (2007C32013)the Natural Science Foundation of Zhejiang Province, China (Y3090660)
文摘Faba bean （Vicia faba L.）, one of the most important legumes in the world, evolved different types of cultivars due to its partial cross-pollination. The development of simple sequence repeat （SSR） markers from expressed sequence tags （EST） provided a useful tool for investigation of its genetic diversity. The purpose of the present study was to investigate the genetic diversity of faba bean from China and Europe using EST-SSR markers. 5 031 faba bean ESTs from the NCBI database were downloaded and assembled into 1 148 unigenes. A total of 107 microsatellites in 96 unigenes were identified, indicating that merely 8.36% of sequences contained SSRs. The most abundant SSR within faba bean was tri-nucleotide repeat motif, and among all the tri-nucleotide repeats, the motif AAG/CTT was the most abundant type. Based on these results, 11 EST-SSR markers were used to assess the genetic diversity of 29 faba bean cultivars from China and Europe with two to three alleles per locus. The polymorphism information content value ranged from 0.0644 to 0.4278 with an average of 0.2919. Principal coordinate analysis （PCA） and phylogenetic clustering based on these 11 EST-SSR markers distinguished these cultivars into different groups. The results indicated that faba bean in China had a narrow genetic basis, and the additional sources of genetic cultivars/accessions should be introduced to enhance the genetic variability. The results of this study proved that the EST-SSR marker is very effective in evaluation of faba bean germplasm.
文摘Fifteen expressed sequence tag (EST)-derived simple sequence repeats (EST-SSRs) were used to investigate genetic diversity in 139 plants obtained from seeds of 35 watermelon accessions collected from all the geographical provinces of Zimbabwe. In addition, 15 plants representing three commercial varieties developed in the United States (USA) were analyzed for comparison. A total of 65 alleles were detected among all the watermelon accessions. For the 13 polymorphic EST-SSR loci, number of alleles per locus varied from 2 to 13, with an average of 5 alleles per locus. Values for the polymorphic information content increased as the number of alleles increased, and varied from 0.15 to 0.77 with an average of 0.54 suggesting sufficient discriminatory power. Both cluster analysis and principal coordinate analysis (PCA) produced two major clusters;one with the 22 cow-melon accessions and the other with the 16 sweet watermelon accessions. Within the sweet watermelon group, two distinct sub-clusters formed, one of which contained only two of the commercial varieties from USA. Partitioning of genetic variation in the Zimbabwean material using analysis of molecular variation (AMOVA) revealed that 64% of the total variation resides between the two major forms, i.e. sweet watermelons and cow-melons, 28% between accessions within forms and 8% within accessions. The EST-SSR markers revealed a somewhat higher diversity in sweet watermelon accessions compared to that of cow-melons. This finding is contrary to previous reports using other markers (genomic SSR loci or RAPD) and/or a plant material that is likely to have experienced more stringent selection procedures compared to the landraces analyzed in our study.
基金Supported by National Natural Science Foundation of China(31160175,31440034)Project for Protection and Utilization of Crop Germplasm Resources,Ministry of Agriculture(NB2012-2130135)+2 种基金Program of Technological Innovation Talents of Yunnan Province(2011CI068)Project for Construction of National Tea Modern Industrial Technology System of China(NYCYTX-23)Special Fund of Yunnan Academy of Agricultural Sciences(YAAS2012ZY002)
文摘In this study, 27 pairs of EST-SSR primers were employed to analyze the genetic diversity and genetic relationship of 100 wild tea plant germplasm re- sources and 22 cultivars, according to the results, a total of 88 polymorphic bands were amplified with 27 pairs of primers; the variation of effective alleles accounted for 69.01% ; a total of 183 genotypes were detected, with a variation range of 4 -11 ; averagely 6.78 genotypes were amplified with each primer pair; Shannon index （I） of 27 primer pairs ranged from 0.32 to I. 35, with an average of 0.88 ; the observed heterozygosity （0.52） was basically consistent with the expected het- erozygosity （0.52） ; the average polymorphism heterozygosity was 0.48, which was very close to 0.50 ; the average Nei＇s index was 0.51, which was higher than 0. 50 ; the average polymorphism information content （PIC） was 0.52, which was higher than 0.50, indicating high genetic diversity among wild tea germplasm resources in Yuunan Province. According to the clustering results, based on geographical origins and genetic backgrounds, 122 materials were clustered into 14 categories. Dendrogram based on Nei＇s genetic distance revealed complex genetic relationships among wild tea germplasm resources in Yunnan Province. This study provided certain reference for subsequent preservation, development and research of wild tea germplasm resources in China.
文摘EST sequences of Mentha piperita available in the public domain(NCBI) were exploited to develop SSR markers. A total of 1316 ESTs were assembled into 155 contigs and 653 singletons and of these, 110 sequences were found to contain 130 SSRs, with a frequency of1 SSR/3.4 kb. Dinucleotide repeat SSRs were most frequent(72.3%) with the AG/CT(43.8%)repeat motif followed by AT/AT(16.2%). Primers were successfully designed for 68SSR-containing sequences(62.0%). The 68 primers amplified 13 accessions of M. piperita and 54 produced clear amplicons of the expected size. Of these 54, 33(61%) were found to be polymorphic among M. piperita accessions, showing from 2 to 4 alleles with an average of2.33 alleles/SSR, and the polymorphic information content(PIC) value varied between 0.13 and 0.51(average 0.25). All the amplified SSRs showed transferability among four different species of Mentha, with a highest in Mentha arvensis(87.0%) and minimum in Mentha citrata(37.0%). The newly developed SSRs markers were found to be useful for diversity analysis, as they successfully differentiated among species and accessions of Mentha.
文摘Cryptromeria fortunei is one of the main forest plantation species in the subtropical high altitude areas in China. In this paper we collected 49 C. fortunei germplasm resources and provides a study of the utility of freely available C. japonica EST resources for the development of markers necessary for genetic diversity analyses of C. fortunei. By screening 24,299 EST sequences from C. japonica with SSR Finder, we identified 2384 ESTs car- rying 2783 SSR motifs. We successfully obtained 364 （15 %） primers from 2419 putative SSR loci. Of the 80 candidate SSR markers tested, 70 （87.5 %） yielded stable and clear PCR products. With those primers, the genetic diversity of 49 C. fortunei we collected was studied. The results showed that 18 primers yield polymorphism within these accessions. These 18 primers generated 48 scorable SSR loci and the average number of polymorphic SSR loci per primer was 2.7. The PIC value varied from 0.375 to 0.8101, with the average of 0.4780. The Shannon index is 0.5718, and the value of the observed number of alleles and effective number of alleles are 1.9167 and 1.7289, respectively. The genetic coefficient of these 49 accessions varied from 0.28 to 0.87. According to the genetic dis- tances, a cluster tree was constructed. At genetic coefficient of 0.60, these 49 accessions can group into 3： group I contains only FJ-laizhou accession, and group II contains 2accessions from FJ-layang, and the other one group con- tains mixed accessions. At genetic coefficient of 0.68, the former group II was constructed into 7 subgroups, with the first 3 subgroups contain 16 accessions in which 11 （69 %） are from Fujian province, and the later 4 subgroup contain 31 accessions in which 20 （65 %） were from Zhejiang province.
