2015 Vol. 33 No. 5
2015, 33(5): 579-594.
DOI: 10.11913/PSJ.2095-0837.2015.50579
Abstract：
The seed morphology of 29 taxa (including 25 species and 4 varieties) from Spiraea L. in China was studied using light microscopy (LM) and scanning electron microscopy (SEM). Results showed that seeds of Spiraea were narrowly linear to elliptic in shape, with testa lustrous and striate, reddish brown to dark brown in color. Ornamentation of seed coat was ascribed into four types, reticulate, double reticulate, areolate and chainlike reticulate. The ratio of seed length to width (L/W) supported the traditional division of the subgroups in this genus. Seed surface sculpture may have definite systematic importance in the taxonomy of Spiraea species.
The seed morphology of 29 taxa (including 25 species and 4 varieties) from Spiraea L. in China was studied using light microscopy (LM) and scanning electron microscopy (SEM). Results showed that seeds of Spiraea were narrowly linear to elliptic in shape, with testa lustrous and striate, reddish brown to dark brown in color. Ornamentation of seed coat was ascribed into four types, reticulate, double reticulate, areolate and chainlike reticulate. The ratio of seed length to width (L/W) supported the traditional division of the subgroups in this genus. Seed surface sculpture may have definite systematic importance in the taxonomy of Spiraea species.
2015, 33(5): 595-601.
DOI: 10.11913/PSJ.2095-0837.2015.50595
Abstract：
Scanning electron microscope (SEM) and light microscope (LM) were used to examine the development and function of the strumae on the adaxial sides of the inner petals of Oncodostigma hainanense. We found that no struma formed at stageⅠ and Ⅱ of bud development. However, obvious strumae were formed at stage Ⅲ, which protruded outwards from the plane of tissue. Strumae were fully developed at stage Ⅳ. The periodic acid-schiff (PAC) reaction indicated that polysaccharides increased with the formation of strumae and were mainly distributed in cells around the strumae at stage Ⅳ. We have observed some thrip larvae among mature strumae, but no secretive opening or secretion on the surface of the strumae was found. We speculated that the strumae on the adaxial sides of the inner petals provided flower visitors a nutritious and safe place for mating, oviposition, brooding and perhaps some food such as polysaccharides.
Scanning electron microscope (SEM) and light microscope (LM) were used to examine the development and function of the strumae on the adaxial sides of the inner petals of Oncodostigma hainanense. We found that no struma formed at stageⅠ and Ⅱ of bud development. However, obvious strumae were formed at stage Ⅲ, which protruded outwards from the plane of tissue. Strumae were fully developed at stage Ⅳ. The periodic acid-schiff (PAC) reaction indicated that polysaccharides increased with the formation of strumae and were mainly distributed in cells around the strumae at stage Ⅳ. We have observed some thrip larvae among mature strumae, but no secretive opening or secretion on the surface of the strumae was found. We speculated that the strumae on the adaxial sides of the inner petals provided flower visitors a nutritious and safe place for mating, oviposition, brooding and perhaps some food such as polysaccharides.
2015, 33(5): 602-607.
DOI: 10.11913/PSJ.2095-0837.2015.50602
Abstract：
Osmophores specialized and defined on the labellum of Lowiaceae plants can produce a strong scent, unpleasant to humans but attractive to pollinators, which mimics the odor of carrion or decaying fruit during anthesis. In the present study, the labellum of Orchidantha chinensis var. longisepala was stained in vivo with neutral red to ascertain the location of osmophores. We used scanning electron microscopy (SEM) to observe the morphology of epidermal cells and transmission electron microscopy (TEM) to explore the ultrastructure of secretory cells. Results showed that osmophores of O. chinensis var. longisepala were located at adaxial surface of the upper labellum. Diverse epidermal cells and 1-2 layers of secretory cells comprised the osmophores. Cells of the glandular tissue showed enlarged nuclei compared to cells of nearby tissue and a dense cytoplasm. These cells also have more endoplasmic reticulum, mitochondria and plastids, sometimes dictyosomes. The scent substances were mainly from rupturing outer layer of the cuticle, and the diffusion of small molecules may contribute to the release. Research on the osmophores of Lowiaceae is useful to reveal the interactions between plants and pollinators and study the process of pollination.
Osmophores specialized and defined on the labellum of Lowiaceae plants can produce a strong scent, unpleasant to humans but attractive to pollinators, which mimics the odor of carrion or decaying fruit during anthesis. In the present study, the labellum of Orchidantha chinensis var. longisepala was stained in vivo with neutral red to ascertain the location of osmophores. We used scanning electron microscopy (SEM) to observe the morphology of epidermal cells and transmission electron microscopy (TEM) to explore the ultrastructure of secretory cells. Results showed that osmophores of O. chinensis var. longisepala were located at adaxial surface of the upper labellum. Diverse epidermal cells and 1-2 layers of secretory cells comprised the osmophores. Cells of the glandular tissue showed enlarged nuclei compared to cells of nearby tissue and a dense cytoplasm. These cells also have more endoplasmic reticulum, mitochondria and plastids, sometimes dictyosomes. The scent substances were mainly from rupturing outer layer of the cuticle, and the diffusion of small molecules may contribute to the release. Research on the osmophores of Lowiaceae is useful to reveal the interactions between plants and pollinators and study the process of pollination.
2015, 33(5): 608-619.
DOI: 10.11913/PSJ.2095-0837.2015.50608
Abstract：
Ecological stoichiometry studies the balance between multiple chemical elements in ecological processes. It is a theory, a way of thinking and a tool. The key problem for ecological stoichiometry is to reveal the effects of variations in the elemental composition of organisms in regards to ecological functions. Ecological stoichiometry can permeate all aspects of ecology because it can unify all ecological processes (from molecules to the biosphere). Key principles (homeostasis and growth rate hypothesis) of ecological stoichiometry are based upon elemental stoichiometry which is the core of ecological stoichiometry. Combined with our own research, we reviewed a number of new achievements in ecological stoichiometry in aquatic ecosystems. This review will help advance studies and applications of ecological stoichiometry in aquatic ecosystems in China.
Ecological stoichiometry studies the balance between multiple chemical elements in ecological processes. It is a theory, a way of thinking and a tool. The key problem for ecological stoichiometry is to reveal the effects of variations in the elemental composition of organisms in regards to ecological functions. Ecological stoichiometry can permeate all aspects of ecology because it can unify all ecological processes (from molecules to the biosphere). Key principles (homeostasis and growth rate hypothesis) of ecological stoichiometry are based upon elemental stoichiometry which is the core of ecological stoichiometry. Combined with our own research, we reviewed a number of new achievements in ecological stoichiometry in aquatic ecosystems. This review will help advance studies and applications of ecological stoichiometry in aquatic ecosystems in China.
2015, 33(5): 620-632.
DOI: 10.11913/PSJ.2095-0837.2015.50620
Abstract：
The genus Sagittaria belongs to Alismataceae, of which many aquatic plants have worldwide distribution. The plants in Sagittaria live in diverse habitats, with complex phenotypic response to their environment (both vegetative and reproductive), and are basal lineages in monocots, which make them a good study system for ecologists and evolutionary biologists. Among all related studies on Sagittaria, this review generalized the species of interest, the questions being asked and their conclusions. Typically, there are both common and endangered species in this genus, and ecological factors probably account for the endangerment. Some Sagittaria species have become invasive weeds in areas of paddy fields;however, competitive ability seems variable depending on different rice cultivars. Environment plays a big role in shaping phenotypes and has a large effect on the community structure of aquatic systems with Sagittaria plants. There are relatively high levels of genetic variation in Sagittaria species. With regard to reproduction, the plants show tradeoffs between sexual and asexual reproduction, and between two gender functions. There is strong evidence in the evolutionary path from monoecy to dioecy in S. trifolia. In this review, we also mention the lack of research in certain areas, emphasize some methods and ideas, and point out future directions.
The genus Sagittaria belongs to Alismataceae, of which many aquatic plants have worldwide distribution. The plants in Sagittaria live in diverse habitats, with complex phenotypic response to their environment (both vegetative and reproductive), and are basal lineages in monocots, which make them a good study system for ecologists and evolutionary biologists. Among all related studies on Sagittaria, this review generalized the species of interest, the questions being asked and their conclusions. Typically, there are both common and endangered species in this genus, and ecological factors probably account for the endangerment. Some Sagittaria species have become invasive weeds in areas of paddy fields;however, competitive ability seems variable depending on different rice cultivars. Environment plays a big role in shaping phenotypes and has a large effect on the community structure of aquatic systems with Sagittaria plants. There are relatively high levels of genetic variation in Sagittaria species. With regard to reproduction, the plants show tradeoffs between sexual and asexual reproduction, and between two gender functions. There is strong evidence in the evolutionary path from monoecy to dioecy in S. trifolia. In this review, we also mention the lack of research in certain areas, emphasize some methods and ideas, and point out future directions.
2015, 33(5): 633-640.
DOI: 10.11913/PSJ.2095-0837.2015.50633
Abstract：
The hyperspectral technique is a robust method that can accurately identify surface features via the high resolution detection of spectral features. It has wide application prospects in the study of ecological processes and properties. Here, we systemically reviewed the implication of the hyperspectral technique in soil, plant physiology, quality detection of agricultural products and litter decomposition based on its principles, characteristics, advantages and analysis processes. Its disadvantages and drawbacks were also discussed to allow for better application in ecology.
The hyperspectral technique is a robust method that can accurately identify surface features via the high resolution detection of spectral features. It has wide application prospects in the study of ecological processes and properties. Here, we systemically reviewed the implication of the hyperspectral technique in soil, plant physiology, quality detection of agricultural products and litter decomposition based on its principles, characteristics, advantages and analysis processes. Its disadvantages and drawbacks were also discussed to allow for better application in ecology.
2015, 33(5): 641-726.
DOI: 10.11913/PSJ-2095-0837.2015.50641
Abstract：
Xishuangbanna in southern Yunnan is a global biodiversity hotspot. Based on physiognomic and ecological characteristics, floristic composition and habitats, the primary forest vegetation in Xishuangbanna can be categorized into seven main vegetation types and thirtytwo formations: tropical rainforest, tropical seasonal moist forest, tropical monsoon forest, tropical lower montane evergreen broadleaved forest, topical palm forest, tropical coniferous forest and bamboo forest. Due to conspicuous similarity in regards to ecological and floristic characteristics, the tropical rainforest in Xishuangbanna is a type of tropical Asian rainforest. The monsoon forest in Xishuangbanna is a tropical deciduous forest under the influence of a strong monsoon climate and is considered a transitional vegetation type between tropical rainforest and savanna in physiognomy and distribution. The tropical montane evergreen broadleaved forest is the main montane vegetation type in the region. It is considered a distinct vegetation type from the northern margin of mainland southeastern Asia, controlled by a strong seasonal climate, based on its floristic and physiognomic characteristics. This article is a synthetic study on the vegetation of Xishuangbanna and the aim is to provide a reference for scientific research, biodiversity conservation and nature reserve management.
Xishuangbanna in southern Yunnan is a global biodiversity hotspot. Based on physiognomic and ecological characteristics, floristic composition and habitats, the primary forest vegetation in Xishuangbanna can be categorized into seven main vegetation types and thirtytwo formations: tropical rainforest, tropical seasonal moist forest, tropical monsoon forest, tropical lower montane evergreen broadleaved forest, topical palm forest, tropical coniferous forest and bamboo forest. Due to conspicuous similarity in regards to ecological and floristic characteristics, the tropical rainforest in Xishuangbanna is a type of tropical Asian rainforest. The monsoon forest in Xishuangbanna is a tropical deciduous forest under the influence of a strong monsoon climate and is considered a transitional vegetation type between tropical rainforest and savanna in physiognomy and distribution. The tropical montane evergreen broadleaved forest is the main montane vegetation type in the region. It is considered a distinct vegetation type from the northern margin of mainland southeastern Asia, controlled by a strong seasonal climate, based on its floristic and physiognomic characteristics. This article is a synthetic study on the vegetation of Xishuangbanna and the aim is to provide a reference for scientific research, biodiversity conservation and nature reserve management.
