Abstract:

【Objective】 Study on the effect of Zn on maize seed germination and growth under microplastics.【Methods】 The effects of different single and combination treatments of zinc (Zn) and three microplastics: polyethylene (PE), polypropylene (PP) and polyvinyl chloride (PVC) on the germination of maize seeds and their growth was investigated using maize seeds.【Results】 Maize seed germination, germination index, germination potential, vigor index, stem length, and root length generally showed a decreasing trend with increasing concentrations of Zn mono-treatment.The three microplastics had slight effects on the germination and growth of maize seeds compared to Zn.Maize germination, maize germination index, germination potential, and vigor index were greater in the combined Zn and microplastic treatments than in the corresponding Zn mono-treatment.Maize germination was 14.29%, 14.29%, and 9.52% higher under 50 mg/L Zn + 100 mg/L PE, 50 mg/L Zn + 100 mg/L PP, 50 mg/L Zn + 100 mg/L PVC treatments, respectively, as compared to 50 mg/L Zn mono-treatment.Germination index, germination potential, and vigor index were 59.10%, 76.91%, and 131.16% higher under 100 mg/L Zn+PE100 mg/L PE treatment and 15.76%, 39.53%, and 15.47% higher under 50 mg/L Zn+100 mg/L PVC treatment compared to 100 mg/L Zn treatment, respectively.Maize seed stem and root length increased with increasing PE concentration under 50 mg/L Zn+PE treatment.For Zn+PP treatments, maize stem lengths were all lower than the corresponding Zn mono-treatments, and root lengths were 45.35% higher at 50 mg/L Zn+100 mg/L PE compared to 50 mg/L Zn, 45.20% higher at 50 mg/L Zn+100 mg/L PP compared to 50 mg/L Zn, and greatest at 50 mg/L Zn+100 mg/L PVC compared to 50 mg/L Zn by 55.91%.【Conclusion】 The addition of lower concentrations (100 mg/L) of microplastics significantly improves the tolerance of maize seeds to excess Zn and promotes seed germination and growth.

Key words: microplastics; Zn; maize; seed germination and growth

摘要：

【目的】研究微塑料作用下锌对玉米种子萌发与生长影响。【方法】以玉米种子为对象,研究锌(Zn)和3种微塑料[聚乙烯(PE)、聚丙烯(PP)、聚氯乙烯(PVC)]不同单一及复合处理对玉米种子萌发及其生长的影响。【结果】玉米种子发芽率、发芽指数、发芽势、活力指数、茎长和根长总体上均随Zn单一处理浓度升高呈现降低趋势。相比Zn,3种微塑料对玉米种子发芽和生长影响轻微。Zn和微塑料复合处理下,玉米发芽率、玉米发芽指数、发芽势和活力指数均大于相应Zn单一处理。在50 mg/L Zn+100 mg/L PE、50 mg/L Zn+100 mg/L PP、50 mg/L Zn+ 100 mg/L PVC处理下,玉米发芽率分别较50 mg/L Zn单一处理高14.29%、14.29%和9.52%。发芽指数、发芽势、活力指数在100 mg/L Zn+PE100 mg/L PE处理下分别较100 mg/L Zn处理高59.10%、76.91%和131.16%,在50 mg/L Zn+100 mg/L PVC下分别较50 mg/L Zn处理高15.76%、39.53%和15.47%。玉米种子茎和根长在50 mg/L Zn+PE 处理下随着PE浓度增加而增大。对于Zn+PP 处理,玉米茎长均低于相应Zn单一处理,根长在50 mg/L Zn+100 mg/L PE下较50 mg/L Zn高45.35%,在50 mg/L Zn+100 mg/L PP下较50 mg/L Zn高45.20%。在50 mg/L Zn+100 mg/L PVC下最大,较50 mg/L Zn高55.91%。【结论】添加较低浓度(100 mg/L)微塑料,能显著提高玉米种子对过量Zn的耐受性,促进种子发芽和生长。

关键词: 微塑料, 锌, 玉米, 种子萌发与生长