Present research was conducted to understand the characteristics of Trichoderma in the development of combination product involving a lower dose of Cu fungicide that showed promise in the effective management of Phytophthora infestans, the late blight pathogen of potato. Based on Cu tolerance activity, potential Trichoderma strains (viz., TCMS-36, SBIT-32 and TCMS-71) were selected. Electron microscopy (SEM and TEM) studies revealed that tolerant Trichoderma isolates (SBIT-32 and TCMS 36) accumulated Cu on the cell wall, while the sensitive isolate (TCMS 71) was repressed due to penetration of Cu through the cell wall. To elucidate Cu-tolerance, Cu-biosorption by living and dead mycelia of T. asperellum was estimated by atomic absorption spectrophotometer. Both sensitive and tolerant T. asperellum isolates accumulated Cu in their cells all through the observation period of 120 h, with considerable increase in the amount of Cu removed from the cell free supernatant from 24 to 120 h. Isolate TCMS-36 recorded maximum Cu accumulation (0.3506 mg/g) in living mycelia, while SBIT-32 recorded highest accumulation (0.2368 mg/g) in dead mycelia. Effectiveness of Cu tolerant T. asperellum was studied in combination with Cu fungicides; viz., COC (Blitox-50), COH (Kocide) in controlling late blight disease in the field. Among three modes of applications, viz., seed, foliar and seed+foliar, maximum delay in progress of the disease was recorded in seed+foliar application. Dual combination of COC@500 ppm and Trichoderma was found more effective than COC alone @1000 ppm in reducing disease severity. Cu tolerant Trichoderma strains could thus be developed as combination products with Cu-based fungicides for safe and effective management of late blight disease of potato.

中文翻译：

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铜耐受性木霉提高铜对致病疫霉的双重组合的生物效力

目前的研究旨在了解木霉在开发包含较低剂量铜杀菌剂的组合产品中的特征，该产品在有效管理马铃薯晚疫病病原体致病疫霉方面显示出前景。基于铜耐受活性，选择了潜在的木霉菌株（即 TCMS-36、SBIT-32 和 TCMS-71）。电子显微镜（SEM 和 TEM）研究表明，耐受性木霉分离株（SBIT-32 和 TCMS 36）在细胞壁上积累 Cu，而敏感分离株（TCMS 71）由于 Cu 穿透细胞壁而受到抑制。为了阐明铜耐受性，通过原子吸收分光光度计估计了 T. asperellum 的活菌丝和死菌丝对 Cu 的吸附。既敏感又宽容的 T. 在整个 120 小时的观察期内，asperellum 分离株在其细胞中积累了铜，从 24 到 120 小时，从无细胞上清液中去除的铜量显着增加。分离株 TCMS-36 在活菌丝体中记录到最大的铜积累 (0.3506 mg/g)，而 SBIT-32 在死菌丝体中记录到最高积累 (0.2368 mg/g)。研究了耐铜 T. asperellum 与铜杀菌剂联合使用的效果；即，COC (Blitox-50)、COH (Kocide) 在田间控制晚疫病。在三种施用方式中，即种子、叶面和种子+叶面，在种子+叶面施用中记录了病害进展的最大延迟。发现 COC@500 ppm 和木霉的双重组合在降低疾病严重程度方面比单独使用 COC@1000 ppm 更有效。