Clonostachys rosea Strain ST1140: An Endophytic Plant-Growth-Promoting Fungus, and Its Potential Use in Seedbeds with Wheat-Grain Substrate

Abstract

In this study, Clonostachys rosea strain ST1140, a naturally occurring endophyte in healthy roots of a pistachio tree, was identifed morphologically and molecularly through DNA sequencing, and its endophytic ability and growth efect in/on three solanaceous plant species were tested. Three diferent organic substrates (bread wheat-grain, sawdust, and leonardite) were also investigated for their utility in cultivating and multiplying the strain. In-tray and pot experiments, the rates of seed germination and vegetative development of pepper, tomato, and eggplant inoculated with C. rosea at planting were compared to those of non-inoculated controls. In pot experiments, inoculating seedbeds with increasing doses of C. rosea strain ST1140 with wheat-grain substrate resulted in higher plant height values for all plant species, and the strain endophytically colonized the roots of all plant species. In-tray experiments revealed that ST1140 inoculation resulted in 2–4 days earlier and 10% higher germination rates for all plant species, as well as more vigorous and accelerated seedling growth (10–13 days earlier for seedlings at the 4–5 true leaf stage) on all inoculated plant species. Among three diferent organic substrates, wheat-grain was found to be the most efective for long-term cultivation and multiplication of the fungus, which could be of interest for its development as a commercial product. These results promised the strain ST1140’s use as a biofertilizer in seedbeds with a wheat-grain substrate.