Kalimeris integrifolia Turcz. is a root sucker form perennial herb of Compositae. In die late period of growing season, fresh fleshy radicels grow up above the soil surface to develop root-borne buds, which in turn gr...Kalimeris integrifolia Turcz. is a root sucker form perennial herb of Compositae. In die late period of growing season, fresh fleshy radicels grow up above the soil surface to develop root-borne buds, which in turn grow into ramets and taproot. On the basis of observation on numerous samples, methods to classify the age of ramets and buds for the root sucker herbaceous plant population and to estimate the ages of taproots were established according to their morphology. The age of ramets was classified based on the regeneration times of taproot buds. Ramets developed from new root sucker buds were classified as 1 a. After 1 a ramets died, the ramets reproduced from the taproots were 2 a, and so on. New buds from a root sucker were 0 a buds, other age classes of buds were consistent with that of ramets, i.e. buds produced from taproots of I a ramets were 1 a buds, and so on. In the hay clipping meadows of the Songnen Plains, for K. integrifolia population, there are three age classes of ramets, representing a steady age structure. The maximal age of taproots of ramets is 4 a. Among all age classes, the population productivity of 2 a ramets was the highest, and that of I a ramets was the lowest. The ramet productivity increased with ramet age. During the early period of growing season, the productivity of 3 a ramets was the highest, but after the middle of growing season, I a ramets showed the greatest relative growth rate. The population size and age structure in the next year could be accurately forecasted by the number of fresh roots with budlet and present population in late autumn. The potential population in the bud banks was more than two times of the present population, which may provide sufficient substitution in the future.展开更多
Since oil palm (Elaeis guineensis Jacq.) does not breed true, tissue culture-derived material is the resource of choice for achieving oil palm homogeneity in terms of growth and yield. Currently, no genomic tagging me...Since oil palm (Elaeis guineensis Jacq.) does not breed true, tissue culture-derived material is the resource of choice for achieving oil palm homogeneity in terms of growth and yield. Currently, no genomic tagging method is available with which one could verify the ortet (tissue donor oil palm) from which the clonal planting material (ramets) origi-nated, particularly in cases of unsatisfactory performance. Thus, Sime Darby Plantation used 10 genomic microsatellite markers to genotype 8 sets of 5 ramets +1 ortet and 2 single ortets. The average genetic distance (D) among oil palms from the same set of ramets and ortet was 0.0000 with the exception of sets containing off-type ramets (D = [0.0834 - 0.1505]). The dendrogram showed that the ramets and their ortet of origin formed a sub-cluster, confirming their simi-larity. The 10 microsatellite markers were valuable to Sime Darby as tools for verification of ramet-to-ortet relation-ships and for the identification of off-types. Furthermore, the set of 10 markers revealed a high expected heterozygosity (He = 0.634) that is a high expected heterosis effect on which yield depends.展开更多
The crystal Nd 3+∶Sr 6YSc(BO 3) 6 was grown by the top-seeded solution growth method from a Li 6B 4O 9 flux. The s pectral properties of Nd 3+∶Sr 6YSc(BO 3) 6 crystal were investigated. Using Judd-Ofel...The crystal Nd 3+∶Sr 6YSc(BO 3) 6 was grown by the top-seeded solution growth method from a Li 6B 4O 9 flux. The s pectral properties of Nd 3+∶Sr 6YSc(BO 3) 6 crystal were investigated. Using Judd-Ofelt theory to ana lyze the optical strength measured in absorption spectrum, the following spectr al parameters were obtained: parameters of oscillator strengths Ω λ are Ω 2=1.194×10 -20 cm2, Ω 4=4.186×10 -20 cm2 and Ω 6=3.3 51×10 -20 cm2. The radiative lifetime is 322 μs, and the fluorescence b ranch ratios were calculated: β 1=0.465, β 2=0.453, β 3=0.079 and β 4=0.004. The results indicate that Nd 3+∶Sr 6YSc(BO 3) 6 c rystal seems to be a potential high-efficient laser material.展开更多
[Objective] This study aimed to estimate the genetic parameters for milk yield, fat percentage, fat yield and age at first freshening of Chinese Holsteins first lactation cows in Heilongjiang under frigid-temperature ...[Objective] This study aimed to estimate the genetic parameters for milk yield, fat percentage, fat yield and age at first freshening of Chinese Holsteins first lactation cows in Heilongjiang under frigid-temperature and temperature zone. [Method] Records of yield and reproduction from 8 868 Chinese Holstein first lacta- tion cows from 21 herds were utilized to evaluate genetic parameters for Hei- Iongjiangs＇ Chinese Holsteins. Restricted maximum likelihood （REML） method was used with an animal model. [Result] The heritabilities were 0.16 to 0.34 for yields and fat percentage, 0.38 for reproduction （age at the first freshening）, which were similar to estimates for temperate areas from similar methods, except for constituent percentage. Also, the estimates of genetic correlation were high between milk yield and fat yield （0.97）, but were low between milk yield and fat percentage （-0.24）, age at the first freshening （-0.29） and generally antagonistic. [Conclusion] Thus, es- timates of genetic parameters in this frigid and frigid-temperate environment did not differ appreciably from those that occur in temperate dairy areas.展开更多
The influence of the structure parameters on the characteristics of dynamic mixer with striped channels is studied. As results indicate that, given the proper structure parameters, the output of the extruder can be in...The influence of the structure parameters on the characteristics of dynamic mixer with striped channels is studied. As results indicate that, given the proper structure parameters, the output of the extruder can be increased with low energy consumption and stable temperature. Furthermore, the mixing effect will be improved up to or even above that of spherical cavity mixer.展开更多
Forest structure and succession in Wolong Nature Reserve is influenced by the understory dwarf bamboo population. However, less is known about how the forest succession affects the dwarf bamboo population. To examine ...Forest structure and succession in Wolong Nature Reserve is influenced by the understory dwarf bamboo population. However, less is known about how the forest succession affects the dwarf bamboo population. To examine the bamboo ramet population growth of Fargesla nitida （Mltford） Keng f. et Yi and to determine how ramet population structure varies along the succession of coniferous forest, we sampled ramet populations of F. nitida from the following three successional stages： （i） a deciduous broad-leaved （BL） stand; （ii） a mixed broad-leaved coniferous （MI） stand; and （ill） a coniferous （CF） stand. We investigated the population structure, biomass allocation, and morphological characteristics of the bamboo ramet among the three stand types. Clonal ramets, constituting the bamboo population, tended to become short and small with succession. The ramet changed towards having a greater mass investment in leaves, branches and underground roots and rhizomes rather than in the culm. With respect to leaf traits, individual leaf mass and area in the BL stand were markedly bigger than those In both the MI and CF stands, except for no significant difference in specific leaf area. The age distribution showed that the bamboo population approached an older age with succession. The results demonstrate that the ramet population structure of F. nitida is unstable and its growth performance is inhibited by succession.展开更多
Clonal integration benefits clonal plants by buffering environmental stress and increasing resource extraction efficiency.However,the number of connected ramet generations that benefit from clonal integration in a clo...Clonal integration benefits clonal plants by buffering environmental stress and increasing resource extraction efficiency.However,the number of connected ramet generations that benefit from clonal integration in a clonal system has received relatively little attention.A pot experiment was conducted to evaluate the extent of physiological integration within the clonal system of Vallisneria natans consisting of a mother ramet and three sequentially connected offspring ramets.Mother ramets were grown in full sunlight,and offspring ramets were heavily shaded with limited light availability.Stolons between mother ramets and offspring ramets were severed or connected,but connection among the three offspring ramets remained.The photosynthetic ability of unshaded mother ramets of V.natans was significantly enhanced,but their biomass accumulation was greatly reduced when connected to shaded offspring ramets.Clonal integration significantly increased biomass accumulation,C and N availabilities,extracellular enzyme activities and microbial biomass of the first ramet generation(adjacent ramet),but not later ramet generations.Our results indicate that support from the mother ramet of V.natans may be limited to the adjacent offspring ramet in a clonal system under severe light stress,implying an effect of ramet generation.Our results contribute to a better understanding of the hierarchy and segmentation of clonal plants.These findings suggest that the extent of clonal integration plays a vital role in ecological interactions of the ramet population.展开更多
文摘Kalimeris integrifolia Turcz. is a root sucker form perennial herb of Compositae. In die late period of growing season, fresh fleshy radicels grow up above the soil surface to develop root-borne buds, which in turn grow into ramets and taproot. On the basis of observation on numerous samples, methods to classify the age of ramets and buds for the root sucker herbaceous plant population and to estimate the ages of taproots were established according to their morphology. The age of ramets was classified based on the regeneration times of taproot buds. Ramets developed from new root sucker buds were classified as 1 a. After 1 a ramets died, the ramets reproduced from the taproots were 2 a, and so on. New buds from a root sucker were 0 a buds, other age classes of buds were consistent with that of ramets, i.e. buds produced from taproots of I a ramets were 1 a buds, and so on. In the hay clipping meadows of the Songnen Plains, for K. integrifolia population, there are three age classes of ramets, representing a steady age structure. The maximal age of taproots of ramets is 4 a. Among all age classes, the population productivity of 2 a ramets was the highest, and that of I a ramets was the lowest. The ramet productivity increased with ramet age. During the early period of growing season, the productivity of 3 a ramets was the highest, but after the middle of growing season, I a ramets showed the greatest relative growth rate. The population size and age structure in the next year could be accurately forecasted by the number of fresh roots with budlet and present population in late autumn. The potential population in the bud banks was more than two times of the present population, which may provide sufficient substitution in the future.
文摘Since oil palm (Elaeis guineensis Jacq.) does not breed true, tissue culture-derived material is the resource of choice for achieving oil palm homogeneity in terms of growth and yield. Currently, no genomic tagging method is available with which one could verify the ortet (tissue donor oil palm) from which the clonal planting material (ramets) origi-nated, particularly in cases of unsatisfactory performance. Thus, Sime Darby Plantation used 10 genomic microsatellite markers to genotype 8 sets of 5 ramets +1 ortet and 2 single ortets. The average genetic distance (D) among oil palms from the same set of ramets and ortet was 0.0000 with the exception of sets containing off-type ramets (D = [0.0834 - 0.1505]). The dendrogram showed that the ramets and their ortet of origin formed a sub-cluster, confirming their simi-larity. The 10 microsatellite markers were valuable to Sime Darby as tools for verification of ramet-to-ortet relation-ships and for the identification of off-types. Furthermore, the set of 10 markers revealed a high expected heterozygosity (He = 0.634) that is a high expected heterosis effect on which yield depends.
文摘The crystal Nd 3+∶Sr 6YSc(BO 3) 6 was grown by the top-seeded solution growth method from a Li 6B 4O 9 flux. The s pectral properties of Nd 3+∶Sr 6YSc(BO 3) 6 crystal were investigated. Using Judd-Ofelt theory to ana lyze the optical strength measured in absorption spectrum, the following spectr al parameters were obtained: parameters of oscillator strengths Ω λ are Ω 2=1.194×10 -20 cm2, Ω 4=4.186×10 -20 cm2 and Ω 6=3.3 51×10 -20 cm2. The radiative lifetime is 322 μs, and the fluorescence b ranch ratios were calculated: β 1=0.465, β 2=0.453, β 3=0.079 and β 4=0.004. The results indicate that Nd 3+∶Sr 6YSc(BO 3) 6 c rystal seems to be a potential high-efficient laser material.
文摘[Objective] This study aimed to estimate the genetic parameters for milk yield, fat percentage, fat yield and age at first freshening of Chinese Holsteins first lactation cows in Heilongjiang under frigid-temperature and temperature zone. [Method] Records of yield and reproduction from 8 868 Chinese Holstein first lacta- tion cows from 21 herds were utilized to evaluate genetic parameters for Hei- Iongjiangs＇ Chinese Holsteins. Restricted maximum likelihood （REML） method was used with an animal model. [Result] The heritabilities were 0.16 to 0.34 for yields and fat percentage, 0.38 for reproduction （age at the first freshening）, which were similar to estimates for temperate areas from similar methods, except for constituent percentage. Also, the estimates of genetic correlation were high between milk yield and fat yield （0.97）, but were low between milk yield and fat percentage （-0.24）, age at the first freshening （-0.29） and generally antagonistic. [Conclusion] Thus, es- timates of genetic parameters in this frigid and frigid-temperate environment did not differ appreciably from those that occur in temperate dairy areas.
文摘The influence of the structure parameters on the characteristics of dynamic mixer with striped channels is studied. As results indicate that, given the proper structure parameters, the output of the extruder can be increased with low energy consumption and stable temperature. Furthermore, the mixing effect will be improved up to or even above that of spherical cavity mixer.
基金Supported by the State Key Basic Research and Development Plan of China （2002CB111505） and the National Nature Science Foundation of China （30300047, 30500388）. Acknowledgements The authors thank Hans Cornelissen （Vrije Universiteit, Amsterdam, The Netherlands） and Ken Chart （University of the Sunshine Coast, 0ueensland, Australia） for their valuable comments on our earlier manuscript. Thanks are also due to the students from Nanjing Forestry University and Sichuan Agricultural University and the staff of Wolong Subalpine Dark Coniferous Forest Ecosystem Ecological Station, Sichuan Academy of Forestry, who helped with the field work.
文摘Forest structure and succession in Wolong Nature Reserve is influenced by the understory dwarf bamboo population. However, less is known about how the forest succession affects the dwarf bamboo population. To examine the bamboo ramet population growth of Fargesla nitida （Mltford） Keng f. et Yi and to determine how ramet population structure varies along the succession of coniferous forest, we sampled ramet populations of F. nitida from the following three successional stages： （i） a deciduous broad-leaved （BL） stand; （ii） a mixed broad-leaved coniferous （MI） stand; and （ill） a coniferous （CF） stand. We investigated the population structure, biomass allocation, and morphological characteristics of the bamboo ramet among the three stand types. Clonal ramets, constituting the bamboo population, tended to become short and small with succession. The ramet changed towards having a greater mass investment in leaves, branches and underground roots and rhizomes rather than in the culm. With respect to leaf traits, individual leaf mass and area in the BL stand were markedly bigger than those In both the MI and CF stands, except for no significant difference in specific leaf area. The age distribution showed that the bamboo population approached an older age with succession. The results demonstrate that the ramet population structure of F. nitida is unstable and its growth performance is inhibited by succession.
基金the Special Foundation of National Science and Technology Basic Research(2013FY112300)the National Natural Science Foundation of China(31900281).
文摘Clonal integration benefits clonal plants by buffering environmental stress and increasing resource extraction efficiency.However,the number of connected ramet generations that benefit from clonal integration in a clonal system has received relatively little attention.A pot experiment was conducted to evaluate the extent of physiological integration within the clonal system of Vallisneria natans consisting of a mother ramet and three sequentially connected offspring ramets.Mother ramets were grown in full sunlight,and offspring ramets were heavily shaded with limited light availability.Stolons between mother ramets and offspring ramets were severed or connected,but connection among the three offspring ramets remained.The photosynthetic ability of unshaded mother ramets of V.natans was significantly enhanced,but their biomass accumulation was greatly reduced when connected to shaded offspring ramets.Clonal integration significantly increased biomass accumulation,C and N availabilities,extracellular enzyme activities and microbial biomass of the first ramet generation(adjacent ramet),but not later ramet generations.Our results indicate that support from the mother ramet of V.natans may be limited to the adjacent offspring ramet in a clonal system under severe light stress,implying an effect of ramet generation.Our results contribute to a better understanding of the hierarchy and segmentation of clonal plants.These findings suggest that the extent of clonal integration plays a vital role in ecological interactions of the ramet population.
