Population demography, seed production, biomass allocation, net photosynthesis and transpiration of two Leymus chinensis divergent populations and between two years in Songnen plain, northeast China were compared....Population demography, seed production, biomass allocation, net photosynthesis and transpiration of two Leymus chinensis divergent populations and between two years in Songnen plain, northeast China were compared. Strong differences between the dry 1997 and moist 1998 occurred in vegetative shoot and sexual shoot densities, sexual differentiation and tiller densities, as well as in the lengths of inflorescence, seed numbers per inflorescence, seed weights and biomass allocation in each population respectively ( P < 0.01). While strong differences between the two populations occurred in vegetative shoot densities, sexual shoot densities, sexual differentiation and seed weights in each year ( P < 0.01). The differences between the two populations in tiller densities and in biomass allocation to sexual shoots were significant ( P <0.05). But there were no significant differences between the two populations in the lengths of inflorescence, seed numbers per inflorescence and biomass allocation to rhizomes and vegetative shoots ( P >0.05). Excepting the transpiration rate in the early June, the differences between the two populations in net photosynthesis and transpiration rate of vegetative shoots and sexual shoots were strongly significant in the early June and July respectively ( P <0.01). Relative stable variations in population demography and physiological traits between the two populations indicated that they are divergently in the Songnen Plain.展开更多
Leymus chinensis （Trin.） Tzveh is a rhizomatous perennial herbage of Gramineae. Reproduction is mainly by vegetative reproduction. Tillering nodes and rhizomes of L. chinensis serve as organs for both vegetative rep...Leymus chinensis （Trin.） Tzveh is a rhizomatous perennial herbage of Gramineae. Reproduction is mainly by vegetative reproduction. Tillering nodes and rhizomes of L. chinensis serve as organs for both vegetative reproduction and nutrient storage. Water-soluble carbohydrate （WSC） contents were measured in tillering nodes, nodes and Internodes of rhizomes of different age classes of L. chinensis populations at three development stages, namely the dough ripe stage, the vegetative growth stage after full ripeness, and the withering stage, in two habitats： sandy soil and saline-alkaline soil. The results showed that WSC content in tillering nodes of the three age classes of L. chinensis were all markedly decreased with increasing age in both sandy soil and saline-alkaline solh A similar trend of changes In WSC contents was observed in the nodes and internodes of rhizomes in different age classes In both habitats. The highest WSC contents were in 2-age-class nodes and internodes of rhizomes, followed by those In the 1 age class, with the lowest WSC contents found in 3-age-class nodes and internodes of rhizomes at the dough ripe and vegetative growth stages after full ripening. In turn, WSC contents decreased with Increasing age at the withering stage in both habitats. The WSC content in each age class of internode was higher than that in the node of rhizome at three development stages in both habitats.展开更多
The genetic variation and clonal diversity of two divergent types (grey-green and yellow-green) of clonal populations of Leymus chinensis Tzvel at 14 loci were compared. Total gene diversity (HT) and the coefficient o...The genetic variation and clonal diversity of two divergent types (grey-green and yellow-green) of clonal populations of Leymus chinensis Tzvel at 14 loci were compared. Total gene diversity (HT) and the coefficient of genetic differentiation (GST) were all higher for the yellow-green type (HT=0.270; GST= 0.186) than for the grey-green type (HT= 0.250; GST= 0.157) of L. chinensis. Rare alleles usually occurred as heterozygotes rather than homozygotes and significant deviations from Hardy-Weinberg equilibrium were found only at a few loci. This indicated that these two types of populations were mainly out-crossing. Clonal diversity, evenness of clones, and mean clone size were not significantly different between the two types. We found that differences between the clone size and genetic variation of the yellow-green type of populations occurred with different climate and habitat population groups. However, for the grey-green type of populations, these genetic variations decreased under conditions of different climate and habitat population groups.展开更多
文摘Population demography, seed production, biomass allocation, net photosynthesis and transpiration of two Leymus chinensis divergent populations and between two years in Songnen plain, northeast China were compared. Strong differences between the dry 1997 and moist 1998 occurred in vegetative shoot and sexual shoot densities, sexual differentiation and tiller densities, as well as in the lengths of inflorescence, seed numbers per inflorescence, seed weights and biomass allocation in each population respectively ( P < 0.01). While strong differences between the two populations occurred in vegetative shoot densities, sexual shoot densities, sexual differentiation and seed weights in each year ( P < 0.01). The differences between the two populations in tiller densities and in biomass allocation to sexual shoots were significant ( P <0.05). But there were no significant differences between the two populations in the lengths of inflorescence, seed numbers per inflorescence and biomass allocation to rhizomes and vegetative shoots ( P >0.05). Excepting the transpiration rate in the early June, the differences between the two populations in net photosynthesis and transpiration rate of vegetative shoots and sexual shoots were strongly significant in the early June and July respectively ( P <0.01). Relative stable variations in population demography and physiological traits between the two populations indicated that they are divergently in the Songnen Plain.
基金Supported by the National Natural Science Foundation of China （30270260, 30470272, and 30070137）.The authors thank Dr Shang-Yi Tian and Yun-Yang Zhao for assistance with the experiments. The authors are also grateful to Dr Rui Guo and Dr Li Wang for their comments on the manuscript.
文摘Leymus chinensis （Trin.） Tzveh is a rhizomatous perennial herbage of Gramineae. Reproduction is mainly by vegetative reproduction. Tillering nodes and rhizomes of L. chinensis serve as organs for both vegetative reproduction and nutrient storage. Water-soluble carbohydrate （WSC） contents were measured in tillering nodes, nodes and Internodes of rhizomes of different age classes of L. chinensis populations at three development stages, namely the dough ripe stage, the vegetative growth stage after full ripeness, and the withering stage, in two habitats： sandy soil and saline-alkaline soil. The results showed that WSC content in tillering nodes of the three age classes of L. chinensis were all markedly decreased with increasing age in both sandy soil and saline-alkaline solh A similar trend of changes In WSC contents was observed in the nodes and internodes of rhizomes in different age classes In both habitats. The highest WSC contents were in 2-age-class nodes and internodes of rhizomes, followed by those In the 1 age class, with the lowest WSC contents found in 3-age-class nodes and internodes of rhizomes at the dough ripe and vegetative growth stages after full ripening. In turn, WSC contents decreased with Increasing age at the withering stage in both habitats. The WSC content in each age class of internode was higher than that in the node of rhizome at three development stages in both habitats.
文摘The genetic variation and clonal diversity of two divergent types (grey-green and yellow-green) of clonal populations of Leymus chinensis Tzvel at 14 loci were compared. Total gene diversity (HT) and the coefficient of genetic differentiation (GST) were all higher for the yellow-green type (HT=0.270; GST= 0.186) than for the grey-green type (HT= 0.250; GST= 0.157) of L. chinensis. Rare alleles usually occurred as heterozygotes rather than homozygotes and significant deviations from Hardy-Weinberg equilibrium were found only at a few loci. This indicated that these two types of populations were mainly out-crossing. Clonal diversity, evenness of clones, and mean clone size were not significantly different between the two types. We found that differences between the clone size and genetic variation of the yellow-green type of populations occurred with different climate and habitat population groups. However, for the grey-green type of populations, these genetic variations decreased under conditions of different climate and habitat population groups.
