8 X.-W.Zhou et al Crit Rev Biotechnol,Early Online:1-11 the number of breeding H.sinensis,and the dominant H. single cell.The DCXC strain similar to symbiotic yeast has sinensis can defeat other fungi to reduce unnecessary death of been also discovered in the other insects.which maybe benefit the moth larvae of Hepialus.The DCXC will be of high the host insect (Suh et al.,2001).Once they match,the host quality and high yield.Nowadays,the biological character- insect will die and induce Cordyceps to produce a fruiting istics and artificial cultivation of H.sinensis are clearly body,and then the strain enters a new phase of growth or death. studied,which makes it possible to artificially breed the Compared with the fruiting body,mycelium is a more stable fungus (Li et al.,2004;Wang et al.,2004).However,further life form for many fungi,and only when facing some experiments and research are still required to improve the environmental pressures,the fruiting body is produced and availability of artificial cultivation of the fungi. makes the defensive reproduction reaction.In nature,these pressures may be extreme temperature,water,fire,and the Increase the food sources of the moth larvae shortage of food and nutrients.It is difficult for experimental The host larvae of the genus Hepialus is a kind of polyphagous methods to induce the fungus to turn into a fruiting body.If the soil insect.The larvae like to eat these plants including fruiting body is produced,it is likely to be related to one or Cyperaceae,Compositae,Leguminosae sp..Umbelliferae, more environmental pressures.Now,there are more than 10 Liliaceae,Polygonum viviparum L.Polygonum capitatum species of fungi isolated from the DCXC,and the relationship 7000 Buch.-Ham.ex D.Don Prodr,Rheumpumilum L.and Radix between them and the host larvae may be endophyte,associated Codonopsis Lanceolatae.The manual experiments showed or symbiotic (Xu et al.,2002;Zhu et al.,2010). that the rhizome of 15 species plants from 10 families can be fed on by the larvae for growth and amongst them the larvae Study of the anamorph of the DCXC prefer the plants of Cyperaceae,Poaceae,Ranunculaceae, Although many proofs showed that the anamorph of the Polygonaceae and Juncaginaceae (Huang et al.,1989).The DCXC is H.sinensis,people usually have isolated some other uepn d species and density of these plants can decide whether the fungi from the fruit body of the DCXC in practice.Up to now, larvae are suitable to live here.The moth larvae of Hepialus there are about tens of the fungi belonging to more than 10 spp.first eat the leaves of the aboveground plants,and when genera isolated from the DCXC,and these fungi were the temperature drops or frost and snow are coming,they feed regarded to be related to the DCXC's anamorph (Zhang on the fresh rhizome of the plants.The larvae usually never et al.,2010).Among them,some chemical composition and come out of the soil till they pupate and even become the pharmacological effects of some fungi are similar to the DCXC.Enough food resources are very necessary for the DCXC,and so are the molecular properties of reduplicate larvae to grow up healthily.Hepialus spp.is a kind of area of nrDNA (Zhu et al.,2010).As mentioned earlier,the omnivorous insect,and only the larvae take food,while the conidial forms of the DCXC reported are >30.Despite this, pupa and imago cannot eat anything.Therefore,in order to many questions about conidial forms require further study, 3 promote the growth of the larvae and increase their quantity, such as their name,identification,extraction,verification, enough plants that the larvae prefer should be cultivated and repetition and the relationships within them and between them meanwhile inessential and even harmful plants must be swept and the DCXC. away.With the development of plant biotechnology,the tissue and cell culture are becoming more and more mature,and with Study of biodiversity conservation most of the plants the larvae like can be artificially cultivated rapidly,which will be helpful to realize artificial intervention The DCXC only lives in the alpine meadow,so the amount of breeding larvae (Deng Wang,2006;Kondamudi et al., and species of alpine plants are important for the growth of 2009:Zhou et al..2010b). the DCXC.Alpine meadow is one kind of alpine vegetation specially derived from the rise of the Qinghai-Tibetan Plateau, Enhancement of the basic and applied research and there exist abundant endemic species and highly rare and endangered species.So the uniqueness in many aspects of Symbiosis or parasitism these species brings very important scientific research and As some current reports show,the pathogenesis of the DCXC economic values. is a hot discussion topic.Some authors thought the spore was Alpine meadow and its ecosystem can be greatly used to likely to be an infectious agent attacking the moth larvae,but study a series of important scientific problems in a specific the entomopathogency of the DCXC is still in dispute.Based extreme environment,such as the speciation and evolution of on the logical and empirical observation data,some authors plateau vegetation,the heredity,reproduction and ecophysio- reported that the DCXC fungi actually had a symbiotic logical properties of them in adaptive evolution,the effect and relationship with the host insects,and their connection was response of them on global change,the formation and mutually beneficial rather than pathogenetic like a parasite. protection of biodiversity and the productivity of alpine The parasite usually causes death of the host,while the unique meadow.Besides.the social and economic development of match between the host insect and the fungus tends to be the Tibetan Plateau strongly depends on its resources and eco- logically a symbiosis and makes their integration(the DCXC) environment,and animal husbandry has become one of the to live.Perhaps the host insect obtains an energy boost from main industries on the Tibetan Plateau.The conservation of the Cordyceps fungus,and meanwhile it can provide some biodiversity is affected by many factors,such as human nutrition for the latter (Holliday Cleaver,2004.2008). activity,climate,peat exploitation,overgrazing,soil change In the artificial cultivation process,the DCXC strain usually and so on.Therefore,comprehensive measures should be turns out to reproduce asexually as does yeast,and produces a taken for sustainable use of the DCXC resources,including RIGHTS L IN Kthe number of breeding H. sinensis, and the dominant H. sinensis can defeat other fungi to reduce unnecessary death of the moth larvae of Hepialus. The DCXC will be of high quality and high yield. Nowadays, the biological character￾istics and artificial cultivation of H. sinensis are clearly studied, which makes it possible to artificially breed the fungus (Li et al., 2004; Wang et al., 2004). However, further experiments and research are still required to improve the availability of artificial cultivation of the fungi. Increase the food sources of the moth larvae The host larvae of the genus Hepialus is a kind of polyphagous soil insect. The larvae like to eat these plants including Cyperaceae, Compositae, Leguminosae sp., Umbelliferae, Liliaceae, Polygonum viviparum L., Polygonum capitatum Buch.-Ham. ex D. Don Prodr, Rheumpumilum L. and Radix Codonopsis Lanceolatae. The manual experiments showed that the rhizome of 15 species plants from 10 families can be fed on by the larvae for growth and amongst them the larvae prefer the plants of Cyperaceae, Poaceae, Ranunculaceae, Polygonaceae and Juncaginaceae (Huang et al., 1989). The species and density of these plants can decide whether the larvae are suitable to live here. The moth larvae of Hepialus spp. first eat the leaves of the aboveground plants, and when the temperature drops or frost and snow are coming, they feed on the fresh rhizome of the plants. The larvae usually never come out of the soil till they pupate and even become the DCXC. Enough food resources are very necessary for the larvae to grow up healthily. Hepialus spp. is a kind of omnivorous insect, and only the larvae take food, while the pupa and imago cannot eat anything. Therefore, in order to promote the growth of the larvae and increase their quantity, enough plants that the larvae prefer should be cultivated and meanwhile inessential and even harmful plants must be swept away. With the development of plant biotechnology, the tissue and cell culture are becoming more and more mature, and with most of the plants the larvae like can be artificially cultivated rapidly, which will be helpful to realize artificial intervention of breeding larvae (Deng & Wang, 2006; Kondamudi et al., 2009; Zhou et al., 2010b). Enhancement of the basic and applied research Symbiosis or parasitism As some current reports show, the pathogenesis of the DCXC is a hot discussion topic. Some authors thought the spore was likely to be an infectious agent attacking the moth larvae, but the entomopathogency of the DCXC is still in dispute. Based on the logical and empirical observation data, some authors reported that the DCXC fungi actually had a symbiotic relationship with the host insects, and their connection was mutually beneficial rather than pathogenetic like a parasite. The parasite usually causes death of the host, while the unique match between the host insect and the fungus tends to be logically a symbiosis and makes their integration (the DCXC) to live. Perhaps the host insect obtains an energy boost from the Cordyceps fungus, and meanwhile it can provide some nutrition for the latter (Holliday & Cleaver, 2004, 2008). In the artificial cultivation process, the DCXC strain usually turns out to reproduce asexually as does yeast, and produces a single cell. The DCXC strain similar to symbiotic yeast has been also discovered in the other insects, which maybe benefit the host insect (Suh et al., 2001). Once they match, the host insect will die and induce Cordyceps to produce a fruiting body, and then the strain enters a new phase of growth or death. Compared with the fruiting body, mycelium is a more stable life form for many fungi, and only when facing some environmental pressures, the fruiting body is produced and makes the defensive reproduction reaction. In nature, these pressures may be extreme temperature, water, fire, and the shortage of food and nutrients. It is difficult for experimental methods to induce the fungus to turn into a fruiting body. If the fruiting body is produced, it is likely to be related to one or more environmental pressures. Now, there are more than 10 species of fungi isolated from the DCXC, and the relationship between them and the host larvae may be endophyte, associated or symbiotic (Xu et al., 2002; Zhu et al., 2010). Study of the anamorph of the DCXC Although many proofs showed that the anamorph of the DCXC is H. sinensis, people usually have isolated some other fungi from the fruit body of the DCXC in practice. Up to now, there are about tens of the fungi belonging to more than 10 genera isolated from the DCXC, and these fungi were regarded to be related to the DCXC’s anamorph (Zhang et al., 2010). Among them, some chemical composition and pharmacological effects of some fungi are similar to the DCXC, and so are the molecular properties of reduplicate area of nrDNA (Zhu et al., 2010). As mentioned earlier, the conidial forms of the DCXC reported are 430. Despite this, many questions about conidial forms require further study, such as their name, identification, extraction, verification, repetition and the relationships within them and between them and the DCXC. Study of biodiversity conservation The DCXC only lives in the alpine meadow, so the amount and species of alpine plants are important for the growth of the DCXC. Alpine meadow is one kind of alpine vegetation specially derived from the rise of the Qinghai-Tibetan Plateau, and there exist abundant endemic species and highly rare and endangered species. So the uniqueness in many aspects of these species brings very important scientific research and economic values. Alpine meadow and its ecosystem can be greatly used to study a series of important scientific problems in a specific extreme environment, such as the speciation and evolution of plateau vegetation, the heredity, reproduction and ecophysio￾logical properties of them in adaptive evolution, the effect and response of them on global change, the formation and protection of biodiversity and the productivity of alpine meadow. Besides, the social and economic development of the Tibetan Plateau strongly depends on its resources and eco￾environment, and animal husbandry has become one of the main industries on the Tibetan Plateau. The conservation of biodiversity is affected by many factors, such as human activity, climate, peat exploitation, overgrazing, soil change and so on. Therefore, comprehensive measures should be taken for sustainable use of the DCXC resources, including 8 X.-W. Zhou et al. Crit Rev Biotechnol, Early Online: 1–11 Critical Reviews in Biotechnology Downloaded from informahealthcare.com by Fudan University on 07/22/13 For personal use only