Species of fungus
Trichoderma asperellum Samuels, Lieckf & Nirenberg [1] is a naturally occurring species of fungus in the family Hypocreaceae.[2] It can be distinguished from T. viride by molecular and phenotypic characteristics. The most important molecular characteristics are divergent ITS-1 and 28S sequences and RFLP's of the endochitinase gene. Main phenotypic characters are conidial ornamentation and arrangement and branching of the conidiophores.
T. asperellum has been the subject of testing over recent years in terms of its potential use as a treatment for plant growth and protection with positive outlooks for T. asperellum's commercial use. However, T. asperellum remains largely unstudied, especially compared to other members of the Trichoderma genus.
Important Isolates
This species has been used commercially and experimentally as a biopesticide for plant disease control: some commercial isolates were previously placed in T. harzianum. T. asperellum has yet to break into highly popular use as a biopesticide, however strain T34 is sold by Biocontrol Technologies S.L. and is not known to have negative side effects on humans or the environment. T. asperellum T34 is known to be especially effective against Fusarium oxysporum, a pathogen extremely detrimental to the global agricultural industry.
Potential Industry Plant-Growth Use
When applied to the soil in which plants are grown, Trichoderma asperellum has numerous positive effects on commercial agriculture, both benefitting growth and preventing different infections of plants.
Among the most useful of applications of T. asperellum is on the and growth and protection of tomato plants Solanum lycopersicum.[3] T. asperellum can be used as a biological combatant to fusarium wilt disease caused by a variety of fungi in the fusarium genus that are detrimental to plant growth, wherein T. asperellum exhibits compounds able to inhibit growth of fungi that would otherwise kill the host plant. In addition to antifungal properties, T. asperellum promotes germination and faster growth rates of tomato plants that are exposed to fungus. T. asperellum, along with other members of the Trichoderma genus, act as mycoparasites that prevent the spread of other fungi even at small concentrations of application, and is more effective at smaller concentrations than other Trichoderma.[4] T. asperellum acts mycoparisitcally through the production of 12 molecules that antagonize and inhibit the growth of fungal infections to the point of complete elimination of the pathogens.
T. asperellum may also serve as a primer against bacterial infection of treated plants, changing metabolic reactions to infection of bacteria that may persist following infection.[5] Supporting priming may allow plants treated with T. asperellum to react more effectively to environmental factors that would otherwise have negative affects on growth and survival, as well as promoting synthesis of defensive proteins in plants against both bacterial and fungal infections. Through alteration of metabolic reactions, T. asperellum may be able to better inoculate plants against infection creating more resistant crops.
