王文举 孙婷婷 岑光莉 娄文月 陈燕玲 阙友雄 尤垂淮 苏亚春

摘  要：由鞭黑粉菌（Sporisorium scitamineum）引起的黑穗病是甘蔗（Saccharum spp.）生產上最重要的真菌病害。硅是植物生长过程中的有益矿质元素，能够提高植物对生物和非生物胁迫的抗性。目前，关于外源硅对甘蔗黑穗病菌的体外抑菌作用尚未见报道。本研究以硅酸钠（sodium silicate， Na2SiO3）和硅酸钾（potassium silicate， K2SiO3）处理甘蔗黑穗病菌，观察黑穗病菌的孢子萌发、菌落直径和菌丝生长情况，评价不同硅剂和pH对甘蔗黑穗病菌的体外抑菌效果。结果显示，0.5～20.0 mmol/L Na2SiO3和K2SiO3均完全抑制甘蔗黑穗病菌的孢子萌发，但1.0 mmol/L Na2SiO3促进甘蔗黑穗病菌菌落和菌丝的生长，10.0、20.0 mmol/L Na2SiO3和K2SiO3则显著抑制菌落和菌丝的生长，表明Na2SiO3和K2SiO3均会影响甘蔗黑穗病菌的生长，高浓度Na2SiO3和K2SiO3的抑菌效果明显。在不同pH条件下，低pH（5.87～10.86）处理下的甘蔗黑穗病菌孢子有萌发，但其萌发率随着pH的增大逐渐降低，高pH（≥10.96）完全抑制孢子萌发，此外，pH为9.40和11.57对菌落直径的抑制效果明显。调整pH为6.0的低浓度Na2SiO3（0～5.0 mmol/L）和K2SiO3（0～3.5 mmol/L）对孢子萌发影响小，但pH为6.0的高浓度Na2SiO3（7.0～20.0 mmol/L）和K2SiO3（5.0～20.0 mmol/L）显著抑制孢子萌发，表明相同pH水平下的K2SiO3比Na2SiO3及其对应pH处理对甘蔗黑穗病菌孢子萌发的抑制作用更为明显。研究结果为外源硅在甘蔗抗黑穗病的药效试验和防治机理研究提供参考。

关键词：甘蔗黑穗病菌;硅;pH;抑菌作用

中图分类号：S435.661      文献标识码：A

Abstract： Smut caused by Sporisorium scitamineum is the most important fungal disease in Saccharum spp. production. Silicon is a beneficial mineral element in plant growth， which can improve plant resistance to biotic and abiotic stresses. At present， the antifungal effect of exogenous silicon on S. scitamineum in vitro has not been reported. In this study， the spore germination， colony diameter and mycelium growth of the S. scitamineum were observed using sodium silicate （Na2SiO3） and potassium silicate （K2SiO3） to evaluate the antifungal effects of different silicon agents and pH on S. scitamineum in vitro. The spore germination of S. scitamineum was completely inhibited by 0.5–20.0 mmol/L Na2SiO3 and K2SiO3. The colony and hyphal growth of S. scitamineum were promoted by 1.0 mmol/L Na2SiO3， but was significantly inhibited by 10.0 mmol/L and 20.0 mmol/L Na2SiO3 and K2SiO3. The results suggested that Na2SiO3 and K2SiO3 could affect the growth of S. scitamineum， and high concentrations exhibited obvious antifungal effects. The spores could germinate at low pH （5.87–10.86）， but the germination rate gradually decreased with the increase of pH. High pH （≥10.96） completely inhibited the spore germination. In addition， pH 9.40 and pH 11.57 significantly inhibited the colony growth. After adjusting pH to 6.0， low concentrations of Na2SiO3 （0–5.0 mmol/L） and K2SiO3 （0–3.5 mmol/L） had little effects on the spore germination， but high concentrations of Na2SiO3 （7.0–20.0 mmol/L） and K2SiO3 （5.0–20.0 mmol/L） significantly inhibited the spore germination. The results indicated that at the same pH level， the inhibition effect of K2SiO3 on the spore germination of S. scitamineum was better than that of Na2SiO3 and the corresponding pH treatment. This study would provide references for further pesticide effect test and control mechanism research on the resistance of sugarcane to smut.

Keywords： Sporisorium scitamineum; silicon; pH; antifungal effect

DOI： 10.3969/j.issn.1000-2561.2021.12.028

甘蔗（Saccharum spp.）是重要的糖料作物。由鞭黑粉菌（Sporisorium scitamineum）引起的甘蔗黑穗病是甘蔗生产上最重要的真菌病害，严重威胁甘蔗的产量和品质[1-2]。通过分析甘蔗鞭黑粉菌的遗传多样性和群体遗传结构推测该病原菌起源于亚洲，后期可能通过感病甘蔗传播到非洲和美洲[3-4]。……