Associate Professor (Plant Pathology), Department of Plant Pathology, Centre for Plant Protection Studies, Tamil Nadu Agricultural University, Coimbatore 641003, India.
WOS-A-DST, Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore 641003, India.
J Appl Microbiol. 2023 Feb 16;134(2). doi: 10.1093/jambio/lxac074.
Simultaneous management of FOL and RKN causing wilt complex in tomato by chaetoglobosin-producing Chaetomium globosum.
Random survey was carried out to isolate Fusarium and Chaetomium. Twelve Fusarium isolates were characterized, and FOL4 (virulent) was molecularly identified. Wilt complex by FOL, RKN was assessed individually and in combination under greenhouse. RKN (1000 juveniles ml-1) inoculation followed by FOL4 (5 × 105 spores ml-1) accounted for 90% incidence. The chaetoglobosin-producing Chaetomium was isolated, characterized morphologically and molecularly. Among 55 isolates, nine showed >50% inhibition against FOL, and crude culture filtrate showed a significant reduction in RKN egg hatching (15.66%) and juvenile mortality (100%). Chaetomium Cg 40 was confirmed as C. globosum using SCAR marker (OK032373). Among 40 volatile compounds, hexadecanoic acid and 1,2-epoxy-5,9-cyclododecadiene exhibited antifungal and nematicidal properties in GC-MS. High-performance liquid chromatography revealed chaetoglobosin A (0.767 μg μl-1), and the presence of bioactive molecules chaetoglobosin (528.25 m/z), chaetomin (710 m/z), chaetocin (692.8 m/z), chaetoviridin (432.85 m/z), and chaetomugilin (390 m/z) was confirmed by LC/MS/MS. Cg 40 and Cg 6 were able to synthesize the pks1a, b gene responsible for chaetoglobosin, sporulation, and melanin biosynthesis was confirmed by PCR. The application of an aqueous formulation as seed treatment, seedling dip, and soil drenching (application) recorded lowest wilt incidence (11.11%) and gall index (1) with the maximum growth parameter (plant height 51.9 cm), fruit yield (287.5 g), and lycopene content (11.46 mg/100 g).
Cg 40 and Cg 6, containing polyketides, secondary metabolites, antibiotics, chaetoglobosin, and plant growth-promoting ability, showed antifungal and nematicidal properties against the FOL-RKN wilt complex in tomato in vitro and pot culture experiments.
通过产生 chaetoglobosin 的 Chaetomium globosum 同时管理番茄枯萎病复合菌（FOL）和根结线虫（RKN）引起的萎蔫。
进行了随机调查以分离镰刀菌和毛壳菌。对 12 个镰刀菌分离物进行了特征描述，并通过分子鉴定了 FOL4（毒力）。在温室中单独和组合评估了由 FOL、RKN 引起的萎蔫复合病。RKN（1000 条幼虫 ml-1）接种后，FOL4（5×105 个孢子 ml-1）导致 90%的发病率。分离出产生 chaetoglobosin 的毛壳菌，通过形态学和分子特征进行了鉴定。在 55 个分离物中，有 9 个对 FOL 的抑制率超过 50%，粗培养滤液对 RKN 卵孵化（15.66%）和幼虫死亡率（100%）有显著降低作用。使用 SCAR 标记（OK032373）确认 Chaetomium Cg 40 为 C. globosum。在 40 种挥发性化合物中，十六烷酸和 1,2-环氧-5,9-环十二碳二烯具有抗真菌和杀线虫活性，在 GC-MS 中得到证实。高效液相色谱法显示 chaetoglobosin A（0.767μg μl-1），并通过 LC/MS/MS 证实存在生物活性分子 chaetoglobosin（528.25m/z）、chaetomin（710m/z）、chaetocin（692.8m/z）、chaetoviridin（432.85m/z）和 chaetomugilin（390m/z）。Cg 40 和 Cg 6 能够合成负责 chaetoglobosin 的 pks1a、b 基因，通过 PCR 证实了产孢和黑色素生物合成。将水基制剂作为种子处理剂、幼苗浸渍剂和土壤淋洗剂（应用）进行应用，记录到最低的萎蔫发病率（11.11%）和瘿瘤指数（1），同时具有最大的生长参数（株高 51.9cm）、果实产量（287.5g）和番茄红素含量（11.46mg/100g）。
Cg 40 和 Cg 6 含有聚酮、次生代谢物、抗生素、chaetoglobosin 和植物生长促进能力，在体外和盆栽试验中对番茄 FOL-RKN 萎蔫复合病表现出抗真菌和杀线虫特性。
