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Impacts investigation of poisonous plants in southeast of Qinghai-Tibet plateau grassland and the research of pesticidal activity of a poisonous plant— Stellera chamaejasme L.
Li Wang1, Su Zhou2, Chuan-Jiang Tang2, Kai-Zhang Li2, Yao-Hong He1, Fei Gao1, Tai-Ping Hou1* 1Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, People’s Republic of China; and 2Sichuan Grassland General Work Station, Chengdu, Sichuan 610041, People’s Republic of China
Abstract A thorough investigation on poisonous plants in southeast of Qinghai-Tibet Plateau was conducted. It shows that there are 225 species of poisonous plants belong to 33 families and 75 genera. These poisonous plants are distributed in subalpine meadow, subalpine thicket, alpine meadow, alpine thicket and swampy grassland by order, the majority of which with quantity of 162 species are distributed in subalpine meadow. A special investigation was conducted about the harms of Stellera chamaejasme L. to the grassland as well as its insecticidal activity of Stellera chamaejasme L.. It indicates that it has high insecticidal activity against aphides. Keywords: Poisonous plants; Qinghai-Tibet plateau; Stellera chamaejasme L.
1 Introduction
Qinghai-Tibet Plateau is in the southwest of China. It is the highest plateau in the world with average altitude of 4,500 m (14,763 ft) and is known as the Roof of the World. Everest, the highest mountain of the world is located in this area. Northwest Sichuan Natural Grassland, situated at 26-33ºN, 95-104ºE, is in the southwest of Qinghai-Tibet Plateau. The area is 16,300,000 hectares. It is one of the five great rangelands in China (Zhang et al., 2002). Northwest Sichuan Natural Grassland is in the transitional region from mountain-gorge area to inner Qinghai-Tibet Plateau. The climate is cold and half wetness. The vegetation region type is east plateau high-cold thicket-meadow zone (Wu, 1995). In high-cold thicket and high-cold meadow, the species diversity is very high. The plants in the community are mostly the common traditional herbs of Tibetan medicine. There are also lots of poisonous plant species in the community. They can hold back the normal growth of livestock or make their physiology abnormal or even make them dead if eaten as green grass or hay in natural state. In recent years, people become to pay more attention to the unique plant resources of Qinghai-Tibet Plateau. A series of plant species that have fairly good insecticidal activity against the third-instar larvae of Prodenia litura were found from 33 species of plants from Qinghai-Tibet Plateau. They were Daphne tangutiea, Aconitum gymnandrum, Ligularia virgauyea, NardostachysChinensis (Wang et al., 2000). Zhang found that Stellera chamaejasme, Aster tataricus, Allium sikkimense and Aconitum gymnandrum have fairly high insecticidal activity against the fifth-instar larvae of Pieris rapae. (Zhang et al., 2000). These plants are mostly poisonous ones that can poison livestock. Many traditional Tibetan herbs are of high toxicity, such as Aconitum carmichacli, Stellera chamaejasme, Aconitum pendulum, Anisodus tanguticus and so on. So poisonous plants of Qinghai-Tibet Plateau are most likely the valuable resource pool for plant-based insect control agents and medicines of natural 中国科技论文在线 http://www.paper.edu.cn
toxin. Due to the special natural conditions, Northwest Sichuan Natural Grassland has abundant plant resources, including lots of poisonous plant species. Each types of pasture of Northwest Sichuan Natural Grassland have different degree distribution of poisonous plants. However, in recent years, grassland degradation has occurred in certain area of Northwest Sichuan Natural Grassland due to the natural and artificial factors such as over grazing (Zhou, 2004). The proportion of certain poisonous plants including Stellera chamaejasme, Oxytropis, Ligularia virgauyea in the grassland community is growing. These poisonous plants are hazardous to stockbreeding by infesting on pastures and poisoning livestock. So a thorough investigation on the poisonous plants species and their distribution should be made in order to provide valuable information for the utilization and prevention of poisonous plants.
2 Methods of the research on the poisonous plants
The research on poisonous plants includes two approaches which are information gathering and field survey. The information of the poisonous plants are gathered from Flora of China, Flora of Sichuan, Illustrated Handbook of Medicines of Qinghai-Tibet Plateau (plant volume). The field survey has two approaches. Firstly, we get the information of the plant species that can poison livestock by interviewing the local herdsmen. Secondly, in Aba State and Ganzi State representative sample field were set up in different type of grassland including alpine meadow, subalpine meadow, alpine thicket, subalpine thicket and swampy grassland. In the sample field, the plants that livestock wouldn’t eat or they can poison livestock were the subjects of the investigation. The morphological characteristics, habitat type, living place of the plant and locus altitude, air temperature as well as investigation time should be carefully noted down. Then, after collecting the plant sample and taking picture of the plants, we make a taxonomy identification.
3 Results of the investigation of the poisonous plants
3.1 The species of the poisonous plants According to the identification of the plants’ specimens and the conclusion of the colleted information, it is revealed that there are 225 species of poisonous plants in Northwest Sichuan Natural Grassland belonging to 33 families and 75 genera (Table 1).
Table 1 Species statistics for the poisonous plant of Northwest Sichuan Natural Grassland Family species species Equisetaceae Equisetum arvense E.hiemale Ephedraceae Ephedra equisetina Ephedra equisetina Poligonaceae Polygonum manshuriense R.crispus P.hydropiper Rheum officinale P.convolvulus R.palmatum Rumex acetosa R.tonguticum Chenopodtaceae Chenopodium album Phytolaccaceae Phytolacca acinosa Caryophyllaceae Arenaria serpyllifolia 中国科技论文在线 http://www.paper.edu.cn
Ranunculaceae Aconitum kongboense D.batangense A.flavum D.davidii A.gymnandrum D.hui A.pendulum D.kantzeense A.sinomontanum D.kamaonense var glabrescens A.chrysotrichum D.monanthum A.episcopale D.souliei A.longiramosum Ranunculus japonicus A.polyanthum R.longicaulis var nephelogenes A.sungpanense R.tanguticus A.tanguticum R.chuanchingensis A.tatsienense R.hirtellus var.orientalis A.wardii R.louergaiensis A.yachiangense R.ternatus Adonis coerulea R.sinovaginatus Anemone obtusiloba Thalictrum alpinum A.rivularis T.alpinum var elatum A.trullifolia T.atriplex A.exigua T.grandiflorum A.demissa T.rutifolium A.delavayi T.uncatum A.griffithii T.virgatum A.imbricate T.petaloideum A.rockii Trollius farreri Caltha palustris T.ranunculoides C.scaposa T.yunnanensis Cimicifuga foetida T.pumilus var.tehhehensis C.simplex T.pumilus var.Tanguticus Delphinium caeruleum Aquilegia ecalcarata D.grandiflorum A.rockii D.tatsienense A.oxysepala var hansuensis Berberidaceae Berberis dictyophylla B.julianae Papaveraceae Corydalis curviflora C.trachycarpa C.linarioides Chelidonium majus C.melanochlora Meconopsis horridula C.impatiens M.integrifolia C.adunca M.punicea Cruciferae Descurainia sophia Solms-Laubachia pulcherrima Lepidium apetalum Thlaspi arvense Saxifragaceae Saxifraga melanocentra S.tangutica Rosaceae Duchesnea indica Leguminosae Caragana jubata O.melanocalyx Oxytropis glabra O.strobilacea O.kansuensis O.yunnanensis 中国科技论文在线 http://www.paper.edu.cn
O.ochrocephala O.tragacanthoides O.falcata Thermopsis alpina O.bicolor T.lanceolata O.deflexa T.barbata O.hirta Astragalus adsurgens O.latibracteata A.floridus O.leptophylla A.luteolus Euphorbiaceae Euphorbia esula E.micractina E.helioscopia E.griffithii E.humifusa E.heishuiensis E.pekinensis E.stracheyi E.sieboldiana Thymelaeaceae Daphne aurantiaca Stellera chamaejasme D.retusa Wikstroemia chamaedaphne D.tangutica W.gemmata Elaeagnaceae Hippophae rhamnoides Onagraceae Epilobium hirsutum Umbelliferae Bupleurum marginatum Ericaceae Rhododendron decorum R.chryseum R.przewalskii R.fastigiatum R.intricatum R.flavidum R.parvifolium R.websterianum R.thymifolium R.prattii R.violaceum R.sikangense Primulaceae Primula sikkimensis P.prattii P.cockburniana P.pinnatifida P.henrici Gentianaceae Gentiana spathulifolia G.rhodantha G.striata G.algida G.veitchiorum G.sino-ornata G.macrophylla Halenia corniculata G.straminea H.ellipt G.aristata Boraginaceae Myosotis silvatica M.stenophylla M.caespitosa M.stenophylla Microula sikkimensis Labiatae Lamiophlomis rotata Elsholtzia densa Solanaceae Anisodus luridus Przewalskia tangutica A.tanguticus Solanum lyratum Datura stramonium S.nigrum Hyoscyamus miger Scrophulariaceae Lancea tibetica P.verticillata L.hirsuta P.artselaeri Veronica ciliata P.plicata 中国科技论文在线 http://www.paper.edu.cn
V.biloba P.rudis V.vandellioides P.floribunda Pedicularis longiflora var.tubiformis P.roylei P.trichoglossa P.superba P.decorissima Valerianaceae Nardostachys chinensis N.jatamansi Dipsacaceae Dipsacus asper Compositae Aster alpinus Ligularia virgauyea Artemisia hedinii L.dictyoneura Achillea alpind L.duciformis Arctium lappa L.fischeri Anaphalis lactea L.sagitta A.flavescens Petasites japonicus Bidens parviflora Solidago decurrens B.pilosa Senecio scandens B.tripartita Xanthium sibiricum Cirsium japonicum Juncaginaceae Triglochin palustre T.maritimum Gramineae Achnacherum inebrians Araceae Arisaema consanguineum A.elephas Liliaceae Allium sikkimense A.cyaneum Iridaceae Iris chrysographes I.potaninii I.goniocarpa I.ruthenica Tatal: 33 Families 75 Genera 225 Specieses
3.2 The distribution of the poisonous plants The quantity of the species of the poisonous plants varies dependent on the type of the grassland. The poisonous plants are distributed in subalpine meadow, subalpine thicket, alpine meadow, alpine thicket and swampy grassland by order. The subalpine meadow has the majority of the poisonous plants species, accounting to 162 (Table 2). Table 3 shows part of the common poisonous plants in different types of the grassland.
Table 2 Numerical statistics for the distribution of poisonous plants in Northwest Sichuan Natural Grassland Grassland types Species number Percentage alpine meadow 74 32.9 subalpine meadow 162 72.0 alpine thicket 42 18.7 subalpine thicket 77 34.2 swampy grassland 15 6.7
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Table 3 List of common poisonous plants in Northwest Sichuan Natural Grassland Grassland types Plant species alpine meadow Stellera chamaejasme, Ranunculus tanguticus, Thaliotrum alpinum, Caragana spp., Aconitum gymnandrum, Delphinium spp., Przewalskia tangutica, Gentgana spp., Pedicularis spp., Descurainia Sophia, Euphorbia stracheyi, Elsholtzia densa, Ligularia virgauyea, Lamiophlomis rotata, Caltha paluatris subalpine meadow Stellera chamaejasme, Anaphalis lacteal, Ligularia virgauyea, Delphinium.tatsienense, Aconitum gymnandrum, Pedicularis spp., Gentgana spp., Caragana spp., Primula spp., Halenia corniculata, Polygonum spp., Euphorbia esula, Solms-Laubachia pulcherrima Anemone trullifolia, Anemone obtusiloba, Aster alpinus, Arcemisia hedinii, Trollius spp., Ranunculus spp., Thaliotrum spp., Nardostachys chinensis, Bupleurum marginatum, Saxifraga.spp., Anisodus tanguticus, Corydalis traachycarpa, Anemone rivularis, Caltha paluatris, Elsholtzia densa, Allium sikkimense, Thlaspi arvense alpine thicket Rhododendron spp., Berberis dictyophylla, Hippophae rhamnoidea, Iris spp., Meconopsis integrifolia, Meconopsis integrifolia, Caltha scaposa, Euphorbia spp., Microula sikkimensis subalpine thicket Rhododendron spp., Caragana jubata , Berberis dictyophylla ,Berbers julianae, Iris spp., Daphne aurantiaca, Thaliotrum alpinum, Pedicularis spp.,Stellera chamaejasme, Anemone rivularis, Trollius farreri, Gentgana striata, Primula spp., Myosotis silvatica， Ligularia virgauyea, Allium sikkimense, Anisodus luridus, Microula sikkimensis swampy grassland Triglochin palustne, T. maritimum , Caltha paluatris, Thaliotrum alpinum, Trollius spp., Equisetum arvense ,Epilobium hirsutum ,Rumex acetosa
4 The harm of Stellera chamaejasme L. and its insecticidal activity
Stellera chamaejasme L. (family Thymelaeaceae) is a poisonous perennial herbaceous plant with thick root. The whole herb, especially the root is poisonous, but the root has expectorant, pesticidal and edema curing effect as a Chinese traditional medicine. During the longterm fieldwork in Qinghai-Tibet plateau, we found that Stellera chamaejasme L. had become an urgently prevented poisonous and noxious weed plant. They spread very rapidly and infest over a large part of certain pasture and cause toxicosis in livestock gradually. However, we observed that Stellera chamaejasme L. has high insecticidal activity especially against aphides（Hou et al., 2002）.The result has put the potential of the utilization of this poisonous plant. 4.1 The harm to the grassland from Stellera chamaejasme L. Stellera chamaejasme L. has following biological characters such as powerful ability of regeneration, large quantity of seeds, powerful vitality of the seeds, drought enduring, exerting allelopathic action on neighboring vegetation (Shi, 1997). So under the pressure of over grazing, Stellera chamaejasme L. can easily formed dominant species. It makes the natural grassland in which the dominant species were Kobresia spe. and Gramineae spe became the degenerate grassland featuring Stellera chamaejasme L. In degenerate grassland of Ruoergai County, the plant density of Stellera chamaejasme L. was 6-10 one/m2. They seriously restrain the growth of the good-quality forage grass and poison of livestock frequently. After poisoning by eating Stellera chamaejasme L. the animal’s inner organs engorge and haemorrhage. Then the animals suffer from abdominal twinge and 中国科技论文在线 http://www.paper.edu.cn
diarrhea, even collapse to die. After poisoning the pregnant livestock have symptoms such as abortion, limb atony, kissing the ground, eclampsia and death. 4.2 The research on the insecticidal activity of Stellera chamaejasme L. Stellera chamaejasme L. is gathered from subalpine grassland of Qinghai-Tibet plateau in Ruoergai County with altitude up to 3400 m. With bioactivity-guided method, two aphidcide-activity components were isolated from the roots of Stellera chamaejasme L. They are 1,5-Diphenyl-1-pentanone and 1,5-Diphenyl-2-penten-1-one. Bioassays were conducted to examine the contact toxicity of the two components and Omethoate against aphids. It was showed that 1,5-Diphenyl-1-pentanone and 1,5-Diphenyl-2-penten-1-one have high contact toxicity against aphids (Table 4).
Table 4 The toxicity of compound Ⅰand Ⅱ against cotton aphid *
Concentration(g/L) 1.60 0.80 0.40 0.20 0.10 LC50(g/l) Samples Ⅰ 92.3 64.4 42.0 21.0 15.3 0.643 Ⅱ 98.1 91.7 74.6 47.3 18.0 0.251 Omethoate Control (40% emulsifiable 88.1 71.3 48.3 20.3 14.3 0.431 concentrate)
Note：Ⅰis 1,5—Diphenyl—1—Pentanone，Ⅱis 1,5—Diphenyl—2—Penten -- 1—One *The data in the table is the average of three experiments
5 Discussion
It is meaningful for ecological effect of existence and accumulation of the toxic substance in plants (Chen and Zheng, 1987). Northwest Sichuan Natural Grassland is a part of Qinghai-Tibet plateau with harsh natural condition which give great pressure to the plants for living. But during the long evolution time they have already developed perfect self-defending system in morphological and physiological characteristics and so on. The self-defending system includes producing a large quantity of secondary metabolizing products. Much of them are compounds with certain apparent biological activity. This may be one of the reasons for the large number of poisonous plants in Qinghai-Tibet plateau. The ecosystem of the high-cold meadow in Qinghai-Tibet plateau is in poor performance (Zhang et al , 2002). Now, some area of grassland has been degenerating due to over grazing or other natural factors. The amount of poisonous plants is increasing in the plants community in the grassland. The distribution area of the poisonous plants is gradually magnifying. These did great harm to the stockbreeding. So the rational utilization of the poisonous plants is very necessary. Descurainia Sophia and Thlaspi arvense can be cultivated as wild oil plants, Elsholtzia densa, Nardostachys chinensis, Nardostachys jatamanis are plants of which essential oils can be distilled. Stellera chamaejasme, Aster tataricus, Ligularia virgauyea and Aconitum gymnandrum have been researched on plant-based pesticide. Stellera chamaejasme and Oxytropis were used in researching anticancer medicine (Zhang et al.2000, Wu et al.2003). In addition Stellera chamaejasme can be used in paper making, wine making and amylum making. At present, we only make use of few poisonous plant resources of Northwest Sichuan Natural Grassland. There are more poisonous plants that need us to discover and use. 中国科技论文在线 http://www.paper.edu.cn
Poisonous plants are important part of the grassland community. They have certain ecological niche and sustain the stability of the community some degree. In addition, poisonous plants are part of idioplasm resource of grassland plants. So we shouldn’t gather them excessively especially Gentgana macrophylla, Gentgana straminea, Rheum tonguticum and so on.
Acknowledgements
The author gratefully acknowledges the support of NSFC(20372052)and NCET(04-0868).
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*Corresponding author: Tai-Ping Hou , Professor , The tutor of Doctor Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610064, People’s Republic of China Tel.: +86 28 85410992 Fax: +86 28 85239719 E-mail address: [email protected]