收集27个鹅膏菌属物种共38份样本,提取样品基因组DNA,应用通用引物扩增其内转录间隔区(internal transcribed spacer,ITS)、核糖体大亚基(large ribosomal subunit,LSU)、RNA聚合酶的第二大亚基(the second largest subunit of RNA poly...收集27个鹅膏菌属物种共38份样本,提取样品基因组DNA,应用通用引物扩增其内转录间隔区(internal transcribed spacer,ITS)、核糖体大亚基(large ribosomal subunit,LSU)、RNA聚合酶的第二大亚基(the second largest subunit of RNA polymerase II,RPB2)、β-微管蛋白(β-tubulin)基因序列并进行Sanger双向测序,将得到的序列进行校对拼接后与NCBI的GenBank数据库中的参考序列进行比对鉴别物种来源;计算物种的种内、种间Kimura-2-Parameter(K2P)遗传距离并构建系统发育树。结果表明,β-tubulin、ITS基因序列鉴别能力优于RPB2、LSU基因序列,可将β-tubulin与ITS两者联合用于鹅膏菌属的物种鉴别,为有毒蘑菇诱发的食源性中毒风险进行预警。β-tubulin基因序列长度较LSU、ITS、RPB2等基因序列短,适合对深加工的蘑菇制品以及误食毒蘑菇后的呕吐物进行分析,可作为鹅膏菌属中毒事件中物种鉴定及溯源的优选条形码。展开更多
Changes in the sizes of precipitation events in the context of global climate change may have profound impacts on ecosystem productivity in arid and semiarid grasslands. However, we still have little knowledge about t...Changes in the sizes of precipitation events in the context of global climate change may have profound impacts on ecosystem productivity in arid and semiarid grasslands. However, we still have little knowledge about to what extent grassland productivity will respond to an individual precipitation event. In this study, we quantified the duration, the maximum, and the time-integrated amount of the response of daily gross primary productivity (GPP) to an individual precipitation event and their variations with different sizes of precipitation events in a typical temperate steppe in Inner Mongolia, China. Results showed that the duration of GPP-response (τ<sub>R</sub>) and the maximum absolute GPP-response (GPP<sub>max</sub>) increased linearly with the sizes of precipitation events (P<sub>es</sub>), driving a corresponding increase in time-integrated amount of the GPP-response (GPP<sub>total</sub>) because variations of GPPtotal were largely explained by τ<sub>R</sub> and GPP<sub>max</sub>. The relative contributions of these two parameters to GPP<sub>total</sub> were strongly P<sub>es</sub>-dependent. The GPP<sub>max</sub> contributed more to the variations of GPP<sub>total</sub> when P<sub>es</sub> was relatively small (<20 mm), whereas τ<sub>R</sub> was the main driver to the variations of GPP<sub>total</sub> when P<sub>es</sub> was relatively large. In addition, a threshold size of at least 5 mm of precipitation was required to induce a GPP-response for the temperate steppe in this study. Our work has important implications for the modeling community to obtain an advanced understanding of productivity-response of grassland ecosystems to altered precipitation regimes.展开更多
文摘收集27个鹅膏菌属物种共38份样本,提取样品基因组DNA,应用通用引物扩增其内转录间隔区(internal transcribed spacer,ITS)、核糖体大亚基(large ribosomal subunit,LSU)、RNA聚合酶的第二大亚基(the second largest subunit of RNA polymerase II,RPB2)、β-微管蛋白(β-tubulin)基因序列并进行Sanger双向测序,将得到的序列进行校对拼接后与NCBI的GenBank数据库中的参考序列进行比对鉴别物种来源;计算物种的种内、种间Kimura-2-Parameter(K2P)遗传距离并构建系统发育树。结果表明,β-tubulin、ITS基因序列鉴别能力优于RPB2、LSU基因序列,可将β-tubulin与ITS两者联合用于鹅膏菌属的物种鉴别,为有毒蘑菇诱发的食源性中毒风险进行预警。β-tubulin基因序列长度较LSU、ITS、RPB2等基因序列短,适合对深加工的蘑菇制品以及误食毒蘑菇后的呕吐物进行分析,可作为鹅膏菌属中毒事件中物种鉴定及溯源的优选条形码。
基金jointly supported by the National Natural Science Foundation of China(31400425,31570437,41301043,31420103917)the National Key Project of Scientific and Technical Supporting Program(2013BAC03B03)+1 种基金the Funding for Talented Young Scientists of IGSNRR(2013RC203)the Social Foundation of Beijing Academy of Social Sciences(154005)
文摘Changes in the sizes of precipitation events in the context of global climate change may have profound impacts on ecosystem productivity in arid and semiarid grasslands. However, we still have little knowledge about to what extent grassland productivity will respond to an individual precipitation event. In this study, we quantified the duration, the maximum, and the time-integrated amount of the response of daily gross primary productivity (GPP) to an individual precipitation event and their variations with different sizes of precipitation events in a typical temperate steppe in Inner Mongolia, China. Results showed that the duration of GPP-response (τ<sub>R</sub>) and the maximum absolute GPP-response (GPP<sub>max</sub>) increased linearly with the sizes of precipitation events (P<sub>es</sub>), driving a corresponding increase in time-integrated amount of the GPP-response (GPP<sub>total</sub>) because variations of GPPtotal were largely explained by τ<sub>R</sub> and GPP<sub>max</sub>. The relative contributions of these two parameters to GPP<sub>total</sub> were strongly P<sub>es</sub>-dependent. The GPP<sub>max</sub> contributed more to the variations of GPP<sub>total</sub> when P<sub>es</sub> was relatively small (<20 mm), whereas τ<sub>R</sub> was the main driver to the variations of GPP<sub>total</sub> when P<sub>es</sub> was relatively large. In addition, a threshold size of at least 5 mm of precipitation was required to induce a GPP-response for the temperate steppe in this study. Our work has important implications for the modeling community to obtain an advanced understanding of productivity-response of grassland ecosystems to altered precipitation regimes.
