A controlled and up-scalable biosynthetic route to nanocrystalline silver particles with well-defined morphology using cell-free aqueous filtrate of a non-pathogenic and commercially viable biocontrol agent Trichoderma asperellum is being reported for the first time. A transparent solution of the cell-free filtrate of Trichoderma asperellum containing 1 mM AgNO(3) turns progressively dark brown within 5 d of incubation at 25 °C. The kinetics of the reaction was studied using UV-vis spectroscopy. An intense surface plasmon resonance band at ∼410 nm in the UV-vis spectrum clearly reveals the formation of silver nanoparticles. The size of the silver particles using TEM and XRD studies is found to be in the range 13-18 nm. These nanoparticles are found to be highly stable and even after prolonged storage for over 6 months they do not show significant aggregation. A plausible mechanism behind the formation of silver nanoparticles and their stabilization via capping has been investigated using FTIR and surface-enhanced resonance Raman spectroscopy.

This chapter focuses on the nomenclature and taxonomy of Trichoderma spp. (those that are antagonistic to plant pathogenic fungi and those that are pathogenic to crops) based on morphological or molecular traits, and on the integrated analysis of morphological, physiological and molecular data.

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This book, composed of 17 chapters, provides an update on the advances in Trichoderma research, covering most of the aspects related to the biology, genetics, genomics and applications of Trichoderma in human welfare. An introductory chapter presents an overview of Trichoderma and its applications in agriculture, industry, and in human health and the environment. Part I (chapters 2-7) focuses on Trichoderma taxonomy and physiology, specifically on molecular phylogeny, the influence of light on biology, sexual development, asexual development, volatile organic metabolites, and genetics. Part II (chapters 8-12) discusses the physiology, biochemistry, and genetics of Trichoderma-plant interactions, with specific topics on Trichoderma in the rhizosphere, endophytic Trichoderma, the promotion of plant growth and the induction of systemic defence by Trichoderma, metabolomics, and genomics. Part III (chapters 13-17) discusses Trichoderma applications and significance in biofuel production, plant health management, bioactive metabolites, and cell factories, as well as the negative impact of these fungi on human health. This book will be an invaluable tool in furthering basic understanding as well as the commercial success of these economically important fungi.

An isolate of Trichoderma harzianum which is less effective than G. viren.s in suppressing S. rolfsii and R. solani was compared with G. virens for various mechanisms of antagonism /;; vitro, viz., antagonism in dual culture/hyphal parasitism, parasitism of sclerotia, and antibiosis. G. virens and T. harzianum were equally effective in parasitizing the hyphae of /?. solani. Only T. harzianum parasitized the hyphae of 5. rolfsii, and the two antagonists were comparable with respect to antibiosis on the test pathogens. However, G. virens readily parasitized the sclerotia of the test pathogens and was found to be more effective than T. harzianum in destroying the sclerotia. Under SEM, G. virens was found to colonize, penetrate, and sporulate inside the sclerotia of the test pathogens. Parasitism of sclerotia is suggested as the principal mechanism of biological control of S. rolfsii and R. solani by G. virens. Zusammenfassung, ,Verglcicliende antagonistische Eigenschaften von Gliodadium virens und Ti'ichoileyma harzituuim gegen Sdcrotiiim rolfsii und Rhizoctonia solani-Bedeutung beim Versteben der Mechanismen der Biokontrolle Ein Isolat von Trichoderma harzianum, das weniger effektiv bei der Unterdrtickung von Sclerotium rolfsii und Rhizoctonia solani als Glioclailiuni virens ist, wurde mit C virens bei einigen Mechanismen des Antagonismus //; vitro verglichen, z.B. Antagonismus in Dualkulturen/Hyhenparasitismus, Parasitismus der Sklerotien und Antibiosis. Sowohl G. virens als auch T. harzianum waren beim Parasitismus der Hyphen von R. solani gleich zu stellen. Die hyphen von S. roljsi wurden nur durch T. harzianum parasitiert. Beide Antagonisten waren bezuglich ihrer Antibiosis gegenuber dem Testpathogen ahnlich. G. virens jedoch konnte die Sklerotien des Testpathogens rasch parasitieren und wurde als effektiver als T. harzianum bei der Zerstorung der Sklerotien eingestuft. Nach rasterelektronenmikroskopischen Untersuchungen wurde festgestellt, daB G. virens die Sklerotien der Testpathogene kolonisiert, sich hineindrangte und innerhalb der Sklerotien sporuliert. Der Parasitismus der Sklerotien wird als Hauptmcchanismus der biologischen Kontrolle von S. rolfsii und R. .solani durch G. virens dargestellt. Journal series publication number 7199, G.B. Pant University of Agriculture atid Technology, Pantnagar.