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摘要 绿僵菌防治草原蝗虫效果显著，其在草原田间的存活能力影响其持续控害效果。除了侵染昆虫，绿僵菌还具有在植物根际宿存和根内生的生活方式，但相关宿存规律和内生性的研究报道很少。本文研究了绿僵菌在内蒙古草原两种优势种植物羊草和克氏针茅根际的种群数量变化并对其在这两种草的根内宿存进行了鑒定。结果表明，在干旱的内蒙古草原，绿僵菌施用后种群数量在30 d内快速下降，但能够以低密度在羊草、克氏针茅根际土壤中至少延续宿存75 d，羊草根际环境比较利于绿僵菌生存。对菌株egfp基因标记的特异PCR检测证明了绿僵菌在羊草和克氏针茅根内宿存。试验数据为指导植保生物防治中充分利用绿僵菌的昆虫病原性和植物内生特性提供理论基础，也将成为绿僵菌物种生活方式多样性、与植物互作及共进化研究的重要基础。
关键词 金龟子绿僵菌； 根际宿存； 植物内生性； PCR检测； 牧草
中图分类号： S 476
文献标识码： A
DOI： 10.16688/j.zwbh.2018309
Abstract The application ofMetarhizium for grasshopper control has been obtained significant effect in prairie. The survivability of the appliedMetarhizium is related to its sustained control effect in the grassland. In addition to infecting insects， the fungusMetarhizium also has rhizosphere competent and endophytic lifestyle interacting with plants. However， there are few reports on the fungal persistence and endogeneity. In this paper， we studied the population dynamics and endophyticity ofM. anisopliae in the rhizosphere of two dominant plants，Leymus chinensisandStipa krylovii in Inner Mongolia grassland. The results showed that the fungal population decreased rapidly within 30 days， but it could persist at least 75 days in the rhizosphere soil of the two grass species. The rhizosphere ofL. chinensis was more conducive to the fungus’s survival. The endophyticMetarhizium in the grass roots was identified by PCR detection of specificegfplabeling gene in the appliedMetarhizium isolate. The experimental data provided a theoretical basis for making full use of the entomopathogenic and endophytic characteristics ofMetarhizium in plant protection. They would also become important foundation for further study on the diversity ofMetarhizium lifestyles， their interaction and co-evolution with plants.
Key words Metarhizium anisopliae； surviving in rhizosphere； endophyte； PCR detection； pasture
近年，昆虫病原真菌的田间宿存及其与植物互作关系逐渐成为研究热点。绿僵菌属Metarhizium真菌是具有代表性的一类重要昆虫病原真菌，其寄主包括8目200多种昆虫和螨类，被研究作为害虫生物防治剂，用于农、林、草地虫害的防控[1-2]。在草原上，应用绿僵菌防治蝗虫取得令人瞩目的成效[3-5]。研究发现，施用的绿僵菌在田间土壤中有一定的腐生存活能力，从而保持较长的控害效果，马铃薯、花生等作物的根际环境有利于绿僵菌的宿存和增殖[6-8]。还有研究报道，一些绿僵菌种类或菌株对植物起到显著的促生长作用。例如，绿僵菌处理番茄Lycopersicon esculentum后，植株株高、根长、侧根数量和根干重都比对照明显增加[9]。对柳枝稷Panicum virgatum、扁豆Phaseolus vulgaris、玉米Zea mays和花生Arachis hypogaea的研究也发现了绿僵菌促进植株生长的作用[10-12]，
研究者认为绿僵菌与植物存在根际互作和内共生关系。然而，目前报道的绿僵菌宿主植物种类并不多，直接表明绿僵菌的植物内生性实验证据也很有限。Behie
关键词 金龟子绿僵菌； 根际宿存； 植物内生性； PCR检测； 牧草
中图分类号： S 476
文献标识码： A
DOI： 10.16688/j.zwbh.2018309
Abstract The application ofMetarhizium for grasshopper control has been obtained significant effect in prairie. The survivability of the appliedMetarhizium is related to its sustained control effect in the grassland. In addition to infecting insects， the fungusMetarhizium also has rhizosphere competent and endophytic lifestyle interacting with plants. However， there are few reports on the fungal persistence and endogeneity. In this paper， we studied the population dynamics and endophyticity ofM. anisopliae in the rhizosphere of two dominant plants，Leymus chinensisandStipa krylovii in Inner Mongolia grassland. The results showed that the fungal population decreased rapidly within 30 days， but it could persist at least 75 days in the rhizosphere soil of the two grass species. The rhizosphere ofL. chinensis was more conducive to the fungus’s survival. The endophyticMetarhizium in the grass roots was identified by PCR detection of specificegfplabeling gene in the appliedMetarhizium isolate. The experimental data provided a theoretical basis for making full use of the entomopathogenic and endophytic characteristics ofMetarhizium in plant protection. They would also become important foundation for further study on the diversity ofMetarhizium lifestyles， their interaction and co-evolution with plants.
Key words Metarhizium anisopliae； surviving in rhizosphere； endophyte； PCR detection； pasture
近年，昆虫病原真菌的田间宿存及其与植物互作关系逐渐成为研究热点。绿僵菌属Metarhizium真菌是具有代表性的一类重要昆虫病原真菌，其寄主包括8目200多种昆虫和螨类，被研究作为害虫生物防治剂，用于农、林、草地虫害的防控[1-2]。在草原上，应用绿僵菌防治蝗虫取得令人瞩目的成效[3-5]。研究发现，施用的绿僵菌在田间土壤中有一定的腐生存活能力，从而保持较长的控害效果，马铃薯、花生等作物的根际环境有利于绿僵菌的宿存和增殖[6-8]。还有研究报道，一些绿僵菌种类或菌株对植物起到显著的促生长作用。例如，绿僵菌处理番茄Lycopersicon esculentum后，植株株高、根长、侧根数量和根干重都比对照明显增加[9]。对柳枝稷Panicum virgatum、扁豆Phaseolus vulgaris、玉米Zea mays和花生Arachis hypogaea的研究也发现了绿僵菌促进植株生长的作用[10-12]，
研究者认为绿僵菌与植物存在根际互作和内共生关系。然而，目前报道的绿僵菌宿主植物种类并不多，直接表明绿僵菌的植物内生性实验证据也很有限。Behie