有氧条件下污染禾谷镰刀菌的玉米品质变化规律和呕吐毒素的积累动态变化规律

Quality variation and deoxynivalenol accumulation in corn inoculated with Fusarium graminearum under aerobic conditions

摘要:

[目的] 试验旨在考察有氧条件下接种禾谷镰刀菌后玉米品质变化规律和呕吐毒素（脱氧雪腐镰刀菌烯醇Deoxynivalenol，DON；15乙酰基脱氧雪腐镰刀菌烯醇15-acetyldeoxynivalenol，15AC-DON）的积累动态变化规律。[方法] 单因素试验设计，禾谷镰刀菌接种量分别为1×1⁰⁵、1×10⁶、1×10⁷个/g，玉米水分22%，三角瓶中培养，通氧量为1020 m²/m³，温度25±2℃，湿度75%±5%，时间60 d，测定不同时间点玉米培养物中的品质指标和二毒素含量。[结果] 结果表明，禾谷镰刀菌接种量对为禾谷镰刀菌提供N源的粗蛋白质含量无影响（P>0.05），随着培养时间的延长，提供N源的氨基酸含量呈二次曲线变化（P<0.01），提供C源的粗脂肪、淀粉、粗纤维呈线性降低（P<0.01）。酸价呈线性增加（P<0.01），蛋白质溶解度、能量呈线性降低（P<0.01），霉菌总数和毒素DON、15AC-DON呈二次曲线变化（P<0.01）。禾谷镰刀菌产DON的动态规律为，0-15 d毒素产量范围为0.17-0.23 mg/kg，16-20 d毒素产量范围为0.14-0.41 mg/kg，21-60 d毒素产量范围为0.06-0.15 mg/kg；禾谷镰刀菌产15AC-DON的动态规律为，0-5 d毒素产量范围为1.11-5.28 mg/kg，6-15 d毒素产量范围为5.55-10.05 mg/kg，16-60 d毒素产量范围为4.68-12.06 mg/kg。[结论] 玉米品质随禾谷镰刀菌接种量增加和培养时间延长逐渐降低，DON和15AC-DON产量与禾谷镰刀菌接种量呈剂量依赖关系，60 d内二毒素积累存在前期、中期和后期的动态变化规律。

Abstract:

[Objective] The objective of this trial is to investigate the quality variation and the accumulation of deoxynivalenol and 15-acetyldeoxynivalenol in corn with different Fusarium graminearum inoculation under aerobic conditions.[Methods] Single factor experiment design was used, the inoculation amount of Fusarium graminearum was 1×10⁵, 1×10⁶, 1×10⁷ conidia/g, the corn moisture was 22%, cultured in a Erlenmeyer flask, and the oxygen flux was 1020 m²/m³. The temperature was 25±2℃, the humidity was 75%±5%, and the culture time was 60 d. The quality index and two toxins content in corn culture on different culture time were measured.[Results] The amino acid content had a quadratic curve variation (P<0.01), the content of crude fat, starch and crude fiber decreased linearly (P<0.01), the acid value increased linearly (P<0.01), the protein solubility and energy decreased linearly (P<0.01), the mold counting and content of deoxynivalenol, 15-acetyldeoxynivalenol showed a quadratic curve variation (P<0.01). The accumulation dynamic of deoxynivalenol was that the toxin production ranged from 0.17 to 0.23 mg/kg between 0-15 d, from 0.14 to 0.41 mg/kg between 16-20 d, from 0.06 to 0.15 mg/kg between 21-60 d. The accumulation dynamic of 15-acetyldeoxynivalenol was that the toxin production ranged from 1.11 to 5.28 mg/kg between 0 to 5 d, from 5.55 to 10.05 mg/kg between 6-15 d, from 4.68 to 12.06 mg/kg between 16-60 d.[Conclusion] The corn quality decreased gradually with the increase of Fusarium graminearum inoculation amount and culture time. There was a dose-dependent relationship between content of deoxynivalenol, 15-acetyldeoxynivalenol and Fusarium graminearum inoculation amount. The accumulation dynamic of two toxins was found within 60 days.