Vertical polyamide gel electrophoresis was used to investigate isozyme polymorphisms among different isolates （including wild and cultivated） of Porphyra katadai, Porphyra oligospermatangia, Porphyra yezoensis, Porp...Vertical polyamide gel electrophoresis was used to investigate isozyme polymorphisms among different isolates （including wild and cultivated） of Porphyra katadai, Porphyra oligospermatangia, Porphyra yezoensis, Porphyra haitanensis, and a hybridize species （Porphyra yezoensis x Porphyra haitanensis） sampled from China. Whereafter, the analyses of probable minimum loci numbers, observed alleles sum, genetic diversity, and unweighted pair-group arithmetic average （UPGMA） cluster were carded out. After initial activity and resolution testing of bands of 23 enzymes, 6 of them （MDH, ME, LDH, GDH, IDH and G-6-PDH） were proved to be appropriate for analysis of the full sample set. The probable minimum numbers of loci and alleles analyses showed that the five species of Porphyra had an extraordinary consistent result in ME loci and alleles. However, P. katadai and P. oligospermatangia differed from other three species of Porphyra in LDH and GDH loci and alleles. P. katadai was independent in the analyses of MDH and P. oligosperTnatangia and P. haitanensis differed from other three species in IDH analyses. Moreover, P. yezoensis and P. haitanensis were apart from other three species in G-6-PDH analysis. Taking one with another, P. katadai was relatively separated in the probable minimum numbers of loci and alleles analyses. The results indicated that the genetic variation among the five Porphyra species was limited with a genetic identity of 0.7550. The hybridize species （P. yezoensis x P. haitanensis） seemed to be high homologue with P. oligospermatangia, unexpectedly got relatively lower average genetic identities with both P. yezoensis and P. haitanensis. The 4 strains of P. yezoensis were relatively divergent with an average genetic identity of 0.7428, and P. katadai presented the most differentiated, compared with other species, which consistented with the result summarized in the probable minimum numbers of loci and alleles analyses.展开更多
Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the lev...Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8-20.6, and a mean expected heterozygosity of 0.902-0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a rela- tively large number ofbroodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided im- portant information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas.展开更多
[Objective] This study aimed to understand the genetic diversity and breed conservation effect, and to provide reference for future germplasm resources protection and breeding researches of Guangxi Donglan black-bone ...[Objective] This study aimed to understand the genetic diversity and breed conservation effect, and to provide reference for future germplasm resources protection and breeding researches of Guangxi Donglan black-bone chicken. [Method] The wing venous blood of Donglan Black-bone chicken（silky feather and contour feather） was collected, and the total DNA was extracted. The 18 microsatellite loci were amplified by PCR technology, and the obtained gene fragments were scanned. The number of alleles（Na）, number of effective alleles（Ne）, heterozygosity（H） and polymorphism information content（PIC） were determined using Pop Gen 32 biological software to do cluster analysis of Guangxi indigenous chicken breeds. [Result] The18 microsatellite loci of Donglan black-bone chicken were found to be highly polymorphic. A total of 98 alleles were detected out from 80 Donglan black-bone chicken samples. The averages of Na, Ne, PIC and H per locus were 5.44, 2.78, 0.5382 and 0.596 3, respectively. A total of 93 and 98 alleles were detected out from silky- and contour-feather Donglan black-bone chickens, respectively. The averages of Ne per locus were 2.62 and 2.76, of PIC per locus were 0.508 8 and 0.539 8,of H per locus were 0.624 7 and 0.599 1, respectively. The results of cluster analysis showed that there was greater genetic distance between Donglan black-bone chicken and any of other Guangxi indigenous chicken breeds, including three yellow chicken, Xiayan chicken and Nandan Yao chicken, which was consistent with the breed evolution, geographical distribution and breeding history of Donglan black-bone chicken. [Conclusion] There are greater genetic variation and abundant genetic diversity in the conserved population of Donglan black-bone chicken, suggesting abundant genetic diversity and great breeding potential of Donglan black-bone chicken.展开更多
In the present study, the genetic diversity of one selected strain （Pujiang No. 1）, two domesticated populations （GA and HX） and four wild populations （LZ, YN, SS and JL） of blunt snout bream （Megalobrama ambly...In the present study, the genetic diversity of one selected strain （Pujiang No. 1）, two domesticated populations （GA and HX） and four wild populations （LZ, YN, SS and JL） of blunt snout bream （Megalobrama amblycephala） was analyzed using 17 microsatellite markers. The results showed that an average of 4.88-7.65 number of alleles （A）; an average of 3.20-5.33 effective alleles （Ne）; average observed beterozygosity （Ho） of 0.6985-0.9044; average expected beterozygosity （He） of 0.6501--0.7805; and the average polymorphism information content （PIC） at 0.5706-0.7226. Pairwise FST value between populations ranged from 0.0307-0.1451, and Nei＇s standard genetic distance between populations was 0.0938-0.4524. The expected heterozygosities in the domesticated populations （GA and HX） were significantly lower than those found in three wild populations （LZ, SS and JL）, but no difference was detected when compared with the wild YN population. Likewise, no difference was found between the four wild populations or two domesticated populations. The expected heterozygosity in Pujiang No. 1 was higher than the two domesticated populations and lower than the four wild populations. Regarding pairwise Fsr value between populations, permutation test P-values were significant between the GA, HX and PJ populations, but not between the four wild populations. These results showed that the expected beterozygosity in the selected strain of blunt snout bream, after seven generations of selective breeding, was lower than that of wild populations, but this strain retains higher levels of genetic diversity than domesticated populations. The genetic differences and differentiation amongst wild populations, domesticated populations and the genetically improved strain of blunt snout bream will provide important conservation criteria and guide the utilization of germplasm resources.展开更多
A gel electrophoresis method was used to study the genetic diversity of 8 Quercus mongolica populations throughout its range in China. Eleven of 21 loci from 13 enzymes assayed were polymorphic. Q. mongolica maintaine...A gel electrophoresis method was used to study the genetic diversity of 8 Quercus mongolica populations throughout its range in China. Eleven of 21 loci from 13 enzymes assayed were polymorphic. Q. mongolica maintained low level of genetic variation compared with the average Quercus species. At the species level, the mean number of alleles per locus (A) was 1.905, the percentage of polymorphic loci (P) was 52.38%, the observed heterozygosity (Ho) was 0.092 and the expected heterozygosity (He) was 0.099. At the population level, the estimates were A =1.421, P =28.976%, Ho = 0.088, He =0.085. Genetic differentiation (Gst was high among populations, it was 0.107. According to the UPGMA cluster analysis based on the genetic distance, 4 populations located in northeast and 2 populations in southwest of the geographical distribution are classified into 2 subgroups, but there was no clear relationship between genetic distance and geographic distance among populations. The low level of genetic diversity of Q. mongolica might be related to the long-term exploitation as economic tree species in history are comparatively seriously disturbed and damaged by human beings, and most of the existing stands are secondary forests.展开更多
基金sponsored jointly by the Natural Science Foundation of China (No. 40206019)Agricultural Innovation Project of Nantong (No. L4017)
文摘Vertical polyamide gel electrophoresis was used to investigate isozyme polymorphisms among different isolates （including wild and cultivated） of Porphyra katadai, Porphyra oligospermatangia, Porphyra yezoensis, Porphyra haitanensis, and a hybridize species （Porphyra yezoensis x Porphyra haitanensis） sampled from China. Whereafter, the analyses of probable minimum loci numbers, observed alleles sum, genetic diversity, and unweighted pair-group arithmetic average （UPGMA） cluster were carded out. After initial activity and resolution testing of bands of 23 enzymes, 6 of them （MDH, ME, LDH, GDH, IDH and G-6-PDH） were proved to be appropriate for analysis of the full sample set. The probable minimum numbers of loci and alleles analyses showed that the five species of Porphyra had an extraordinary consistent result in ME loci and alleles. However, P. katadai and P. oligospermatangia differed from other three species of Porphyra in LDH and GDH loci and alleles. P. katadai was independent in the analyses of MDH and P. oligosperTnatangia and P. haitanensis differed from other three species in IDH analyses. Moreover, P. yezoensis and P. haitanensis were apart from other three species in G-6-PDH analysis. Taking one with another, P. katadai was relatively separated in the probable minimum numbers of loci and alleles analyses. The results indicated that the genetic variation among the five Porphyra species was limited with a genetic identity of 0.7550. The hybridize species （P. yezoensis x P. haitanensis） seemed to be high homologue with P. oligospermatangia, unexpectedly got relatively lower average genetic identities with both P. yezoensis and P. haitanensis. The 4 strains of P. yezoensis were relatively divergent with an average genetic identity of 0.7428, and P. katadai presented the most differentiated, compared with other species, which consistented with the result summarized in the probable minimum numbers of loci and alleles analyses.
基金supported by grants from the National High Technology Research and Development Program (2012AA10A405-6)National Natural Science Foundation of China (31372524)Special Fund for Independent Innovation of Shandong Province (2013CX80202)
文摘Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8-20.6, and a mean expected heterozygosity of 0.902-0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a rela- tively large number ofbroodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided im- portant information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas.
基金Supported by Guangxi Natural Science Foundation(2013GXNSFDA019013)Fundamental Research Fund of Guangxi Institute of Animal Science(GMYK2014-05)~~
文摘[Objective] This study aimed to understand the genetic diversity and breed conservation effect, and to provide reference for future germplasm resources protection and breeding researches of Guangxi Donglan black-bone chicken. [Method] The wing venous blood of Donglan Black-bone chicken（silky feather and contour feather） was collected, and the total DNA was extracted. The 18 microsatellite loci were amplified by PCR technology, and the obtained gene fragments were scanned. The number of alleles（Na）, number of effective alleles（Ne）, heterozygosity（H） and polymorphism information content（PIC） were determined using Pop Gen 32 biological software to do cluster analysis of Guangxi indigenous chicken breeds. [Result] The18 microsatellite loci of Donglan black-bone chicken were found to be highly polymorphic. A total of 98 alleles were detected out from 80 Donglan black-bone chicken samples. The averages of Na, Ne, PIC and H per locus were 5.44, 2.78, 0.5382 and 0.596 3, respectively. A total of 93 and 98 alleles were detected out from silky- and contour-feather Donglan black-bone chickens, respectively. The averages of Ne per locus were 2.62 and 2.76, of PIC per locus were 0.508 8 and 0.539 8,of H per locus were 0.624 7 and 0.599 1, respectively. The results of cluster analysis showed that there was greater genetic distance between Donglan black-bone chicken and any of other Guangxi indigenous chicken breeds, including three yellow chicken, Xiayan chicken and Nandan Yao chicken, which was consistent with the breed evolution, geographical distribution and breeding history of Donglan black-bone chicken. [Conclusion] There are greater genetic variation and abundant genetic diversity in the conserved population of Donglan black-bone chicken, suggesting abundant genetic diversity and great breeding potential of Donglan black-bone chicken.
基金supported by the National Natural Science Foundation of China(30630051)Doctoral Research Initial Funding from Shanghai Ocean University(A-2400-11-0186)
文摘In the present study, the genetic diversity of one selected strain （Pujiang No. 1）, two domesticated populations （GA and HX） and four wild populations （LZ, YN, SS and JL） of blunt snout bream （Megalobrama amblycephala） was analyzed using 17 microsatellite markers. The results showed that an average of 4.88-7.65 number of alleles （A）; an average of 3.20-5.33 effective alleles （Ne）; average observed beterozygosity （Ho） of 0.6985-0.9044; average expected beterozygosity （He） of 0.6501--0.7805; and the average polymorphism information content （PIC） at 0.5706-0.7226. Pairwise FST value between populations ranged from 0.0307-0.1451, and Nei＇s standard genetic distance between populations was 0.0938-0.4524. The expected heterozygosities in the domesticated populations （GA and HX） were significantly lower than those found in three wild populations （LZ, SS and JL）, but no difference was detected when compared with the wild YN population. Likewise, no difference was found between the four wild populations or two domesticated populations. The expected heterozygosity in Pujiang No. 1 was higher than the two domesticated populations and lower than the four wild populations. Regarding pairwise Fsr value between populations, permutation test P-values were significant between the GA, HX and PJ populations, but not between the four wild populations. These results showed that the expected beterozygosity in the selected strain of blunt snout bream, after seven generations of selective breeding, was lower than that of wild populations, but this strain retains higher levels of genetic diversity than domesticated populations. The genetic differences and differentiation amongst wild populations, domesticated populations and the genetically improved strain of blunt snout bream will provide important conservation criteria and guide the utilization of germplasm resources.
文摘A gel electrophoresis method was used to study the genetic diversity of 8 Quercus mongolica populations throughout its range in China. Eleven of 21 loci from 13 enzymes assayed were polymorphic. Q. mongolica maintained low level of genetic variation compared with the average Quercus species. At the species level, the mean number of alleles per locus (A) was 1.905, the percentage of polymorphic loci (P) was 52.38%, the observed heterozygosity (Ho) was 0.092 and the expected heterozygosity (He) was 0.099. At the population level, the estimates were A =1.421, P =28.976%, Ho = 0.088, He =0.085. Genetic differentiation (Gst was high among populations, it was 0.107. According to the UPGMA cluster analysis based on the genetic distance, 4 populations located in northeast and 2 populations in southwest of the geographical distribution are classified into 2 subgroups, but there was no clear relationship between genetic distance and geographic distance among populations. The low level of genetic diversity of Q. mongolica might be related to the long-term exploitation as economic tree species in history are comparatively seriously disturbed and damaged by human beings, and most of the existing stands are secondary forests.
