Pinus yunnanensis Franch. is an particular conifer tree species in Yunnan-Guizhou plateau in south- west China. The morphological and anatomical traits of needles are important to evaluate geographic variation and pop...Pinus yunnanensis Franch. is an particular conifer tree species in Yunnan-Guizhou plateau in south- west China. The morphological and anatomical traits of needles are important to evaluate geographic variation and population dynamics of conifer species. Seedlings from seven populations of P. yunnanensis were analyzed, look- ing at 22 morphological and anatomical needle traits. The results showed that variations among and within popula- tions were significantly different for all traits and the variance components within populations were generally higher than that among populations in the most tested needle traits. The proportions of three-needle fascicle were significantly different among populations. The traits related to needle size in both morphology and anatomy were positive with latitude and negative with annual temperature and precipitation. Ratio indices, including mesophyllarea/vascular bundle area, mesophyll area/resin canals area, vascular bundle area/resin canals area and mesophyU area/（resin canals area and vascular bundle area）, were negatively correlated with elevation and positively corre- lated with the annual mean temperature, showing some fitness feature for the populations. Needle traits were more significantly correlated with longitude than with other four environmental factors. Needle length was significantly correlated with almost all environmental factors. First four principal components accounted for 81.596 % of the variation with eigenvalues 〉1; the differences among populations were mainly dependent on needle width, stomatal density, section areas of vascular bundle, total resin canals, and mesophyll, as well as area ratio traits. Seven populations were divided into three categories by Euclidean distance. Variations in needle traits among the populations have shown systematic microevolution in terms of geographic impact on P. yunnanensis. This study would provide empirical data to characterize adaptation and genetic variation of P. yunnanensis, which would be helpful for management of genetic resources and reason- able utilization of them in future.展开更多
Variations in the phenotypic characteristics of conifer needles is a consequence of genetic evolution that has been widely used in geographic variation and ecological studies.Although many studies are based on an in s...Variations in the phenotypic characteristics of conifer needles is a consequence of genetic evolution that has been widely used in geographic variation and ecological studies.Although many studies are based on an in situ sampling strategy and generally realize the contribution of environmental effects to variation in needle traits,it is still uncertain which needle traits are most influenced by genetic effects and which are most influenced by the environment.Using both a common garden experiment to eliminate environmental heterogeneity and an in situ sampling strategy,we compared 18 Pinus tabuliformis needle traits among 10 geographical populations.Using both sampling strategies,we found significant differences in needle traits among populations and among individuals within populations.Differences in the‘‘among-population’’variance component between the two sampling strategies revealed the environmental contribution among natural populations for each trait.The among-population variance in the following traits exceeded 8%:needle length,number of stomata within 2 mm(NS2),number of stomatal lines on the planar side,number of resin canals(RCN)and the resin canal area(RCA).For the stability of needle traits,NS2,RCN,RCA,ratio of the vascular bundle area to the RCA(VBA/RCA),and MA/RCA differed significantly in more than five provenance changes between the common garden populations and natural populations,which may be susceptible to environmental effects.Conversely,the crosssectional area,mesophyll area(MA),MA/(VBA+RCA),and MA/VBA were phenotypically stable.Geographic variation patterns and systematic relation of needle traits differed between the two sampling strategies,suggesting that in situ sampling results may reflect environmental effects and deviate statistical parameters for genetic study.Future studies of genetic evolution in the context of geographic variation should be based on appropriate sampling strategies and stable phenotypic traits.展开更多
Electrical impedance （El） and phase angle （PHI） parameters in AC impedance spectroscopy are important electrical parameters in the study of medical pathology. However, little is known about their application in va...Electrical impedance （El） and phase angle （PHI） parameters in AC impedance spectroscopy are important electrical parameters in the study of medical pathology. However, little is known about their application in variation and genetic relationship studies of forest trees. In order to test whether impedance parameters could be used in genetic relationship analysis among conifer species, E1 and PHI were measured in a seedling experiment test composed of Pinus tabuliformis, Pinus yunnanensis, and Pinus densata in a habitat of Pinus tabuliformis. The results showed that variations in both EI and PHI among species were sig- nificant in different electric frequencies, and the EI and PHI values measured in the two populations of P. densata were between the two parental species, P. yunnanensis and P. tabuliformis. These results show that these two impedance parameters could reflect the genetic relationship among pine species. This was the first time using the two AC impedance spectroscopy parameters to test the genetic relationship analysis between tree species, and would be a hopeful novelreference methodology for future studies in evolution and genetic variation of tree species.展开更多
Camellia oleifera Abel.is an important economic tree species of southern China.In this study,we evaluated the mating system and genetic diversity of a series of cultivars of C.oleifera‘Ruan Zhi’.A total of 159 indiv...Camellia oleifera Abel.is an important economic tree species of southern China.In this study,we evaluated the mating system and genetic diversity of a series of cultivars of C.oleifera‘Ruan Zhi’.A total of 159 individuals from the progenies of four cultivars were tested by simple sequence repeat molecular markers.Results reveal that 11 pairs of primers showed polymorphism and their polymorphism information content value was greater than 0.73,suggesting that these primers could be used to identify the genetic diversity of open-pollinated populations.The average number of effective alleles(Ne=4.88)was significantly different from the average number of alleles(Na=12.18),and their distribution in the sample population was not uniform.The average observed heterozygosity(Ho=0.96)was greater than the average expected heterozygosity(He=0.79),and the population heterozygote was excessive.Shannon index was 1.84 and populations showed high genetic diversity.As regards to the mating system,the multilocus outcrossing rate was 0.996,and the single locus 0.866.These results indicate a high degree of outcrossing by C.oleifera‘Ruan Zhi’.We recommend selecting individuals for high genetic gain from the progenies of cultivars because of outcrossing characteristics and genetic diversity for application to germplasm conservation and promotion.展开更多
基金finically supported by the Natural Science Foundation of China(31070591)Special National Forestry Public Welfare Industry Research(201104022)the support of Southwest Forestry University
文摘Pinus yunnanensis Franch. is an particular conifer tree species in Yunnan-Guizhou plateau in south- west China. The morphological and anatomical traits of needles are important to evaluate geographic variation and population dynamics of conifer species. Seedlings from seven populations of P. yunnanensis were analyzed, look- ing at 22 morphological and anatomical needle traits. The results showed that variations among and within popula- tions were significantly different for all traits and the variance components within populations were generally higher than that among populations in the most tested needle traits. The proportions of three-needle fascicle were significantly different among populations. The traits related to needle size in both morphology and anatomy were positive with latitude and negative with annual temperature and precipitation. Ratio indices, including mesophyllarea/vascular bundle area, mesophyll area/resin canals area, vascular bundle area/resin canals area and mesophyU area/（resin canals area and vascular bundle area）, were negatively correlated with elevation and positively corre- lated with the annual mean temperature, showing some fitness feature for the populations. Needle traits were more significantly correlated with longitude than with other four environmental factors. Needle length was significantly correlated with almost all environmental factors. First four principal components accounted for 81.596 % of the variation with eigenvalues 〉1; the differences among populations were mainly dependent on needle width, stomatal density, section areas of vascular bundle, total resin canals, and mesophyll, as well as area ratio traits. Seven populations were divided into three categories by Euclidean distance. Variations in needle traits among the populations have shown systematic microevolution in terms of geographic impact on P. yunnanensis. This study would provide empirical data to characterize adaptation and genetic variation of P. yunnanensis, which would be helpful for management of genetic resources and reason- able utilization of them in future.
基金funded by the Fundamental Research Funds for the Central Universities(2015ZCQ-SW-02)
文摘Variations in the phenotypic characteristics of conifer needles is a consequence of genetic evolution that has been widely used in geographic variation and ecological studies.Although many studies are based on an in situ sampling strategy and generally realize the contribution of environmental effects to variation in needle traits,it is still uncertain which needle traits are most influenced by genetic effects and which are most influenced by the environment.Using both a common garden experiment to eliminate environmental heterogeneity and an in situ sampling strategy,we compared 18 Pinus tabuliformis needle traits among 10 geographical populations.Using both sampling strategies,we found significant differences in needle traits among populations and among individuals within populations.Differences in the‘‘among-population’’variance component between the two sampling strategies revealed the environmental contribution among natural populations for each trait.The among-population variance in the following traits exceeded 8%:needle length,number of stomata within 2 mm(NS2),number of stomatal lines on the planar side,number of resin canals(RCN)and the resin canal area(RCA).For the stability of needle traits,NS2,RCN,RCA,ratio of the vascular bundle area to the RCA(VBA/RCA),and MA/RCA differed significantly in more than five provenance changes between the common garden populations and natural populations,which may be susceptible to environmental effects.Conversely,the crosssectional area,mesophyll area(MA),MA/(VBA+RCA),and MA/VBA were phenotypically stable.Geographic variation patterns and systematic relation of needle traits differed between the two sampling strategies,suggesting that in situ sampling results may reflect environmental effects and deviate statistical parameters for genetic study.Future studies of genetic evolution in the context of geographic variation should be based on appropriate sampling strategies and stable phenotypic traits.
基金funded by the Natural Science Foundation of China(31070591)Special National Forestry Public Welfare Industry Research(201104022)the support of Agriculture and Animal Husbandry College of Tibet University
文摘Electrical impedance （El） and phase angle （PHI） parameters in AC impedance spectroscopy are important electrical parameters in the study of medical pathology. However, little is known about their application in variation and genetic relationship studies of forest trees. In order to test whether impedance parameters could be used in genetic relationship analysis among conifer species, E1 and PHI were measured in a seedling experiment test composed of Pinus tabuliformis, Pinus yunnanensis, and Pinus densata in a habitat of Pinus tabuliformis. The results showed that variations in both EI and PHI among species were sig- nificant in different electric frequencies, and the EI and PHI values measured in the two populations of P. densata were between the two parental species, P. yunnanensis and P. tabuliformis. These results show that these two impedance parameters could reflect the genetic relationship among pine species. This was the first time using the two AC impedance spectroscopy parameters to test the genetic relationship analysis between tree species, and would be a hopeful novelreference methodology for future studies in evolution and genetic variation of tree species.
基金supported by the applied technology research and development program of Liuzhou(No.2010020401)
文摘Camellia oleifera Abel.is an important economic tree species of southern China.In this study,we evaluated the mating system and genetic diversity of a series of cultivars of C.oleifera‘Ruan Zhi’.A total of 159 individuals from the progenies of four cultivars were tested by simple sequence repeat molecular markers.Results reveal that 11 pairs of primers showed polymorphism and their polymorphism information content value was greater than 0.73,suggesting that these primers could be used to identify the genetic diversity of open-pollinated populations.The average number of effective alleles(Ne=4.88)was significantly different from the average number of alleles(Na=12.18),and their distribution in the sample population was not uniform.The average observed heterozygosity(Ho=0.96)was greater than the average expected heterozygosity(He=0.79),and the population heterozygote was excessive.Shannon index was 1.84 and populations showed high genetic diversity.As regards to the mating system,the multilocus outcrossing rate was 0.996,and the single locus 0.866.These results indicate a high degree of outcrossing by C.oleifera‘Ruan Zhi’.We recommend selecting individuals for high genetic gain from the progenies of cultivars because of outcrossing characteristics and genetic diversity for application to germplasm conservation and promotion.
