孙文泰 马明 董铁 牛军强 尹晓宁 刘兴禄

摘要：为探明陇东旱塬雨养农业区苹果根系年周期生长动态规律及长期覆膜对其根系形态、构型性状的影响，以18 年生红富士长富2号苹果树为试材，于根系3次发根高峰期采用土壤剖面法系统调查清耕（未覆膜，CK）、覆膜2 a、覆膜4 a、覆膜6 a的根系空间分布，对根系形态、构型性状进行测定，并借助根系经济谱理论量化细根生长策略，最终评价苹果细根生长效应。结果表明，根系数量、形态性状生长主要集中于果实采后至落叶的发根高峰，细根生物量占73.55%～84.85%。受树体养分周转与生态环境差异影响，春季萌芽至新梢生长前的发根高峰苹果细根采取获取型的资源获取策略;新梢停长后、果实采后至落叶的发根高峰采取资源保存型获取策略。短期覆膜（2 a）促进苹果细根生长，随覆膜年限延长，逐渐发生生态适应性改变。长期覆膜（6 a）在年生长周期后期根系的形态、构型性状均受抑制，且优先抑制细根构型性状表达。

关键词：苹果树;红富士;根系;年生长周期;旱地;覆膜;细根;根系经济谱理论

中图分类号：S661.1       文献标志码：A       文章编号：1001-1463（2021）10-0055-08

doi：10.3969/j.issn.1001-1463.2021.10.012

Determination of 13 Pesticide Residuesin Lentinus edodes by QuEChERS-GC-MS/MS

REN Jinping

（Pingliang Center for Quality and Safety of Agricultural Products， Pingliang Gansu 744000， China）

Abstract：A rapid method for the determination of 13 pesticide residues in Lentinus edodes was established based on QuEChERS-gas chromatography-mass spectrometry（GC-MS/MS）. After pretreatment， the Lentinus edodes samples were separated by gas chromatography， detected by mass spectrometry in the multi-reaction ion monitoring mode（MRM）， and quantitatively analyzed with the external standard method. The results showed that the 13 pesticides had good linearity in the range from 0.01 μg/mL to 0.8 μg/mL， and the correlation coefficients R2>0.99. The average recovery ranges were mainly between 75.4% and 110.6% at the three spiked concentration levels（0.01、0.10、0.5 0 mg/kg）. The repeatability limit is used to reflect the precision， which all were accepted the requirements of standard GB 23200.113-2018. The method is rapid， efficient and reliable， which is suitable for the detection of pesticide residues in Lentinus edodes samples.

Key words：Lentinus edodes;Pesticide residues;QuEChERS;GC-MS/MS

植物根系通過吸收水分、养分、合成激素对地上部叶片生长、花芽分化、果实发育等产生深刻影响[1 ]。细根（R≤2 mm）是植物根系中最活跃、敏感的部分，生理活性强，在土体中延伸、穿插、固结、根土黏结等改善土壤结构、养分交换，构成地下生态的重要内容[2 ]。细根具有较强的可塑性，可通过改变自身数量、形态、构型性状提高对土壤养分的吸收利用能力[3 ]，并受季节、物候、环境（土壤与气候特征）影响，呈现曲线生长动态。通……