Endophytes in maize (Zea mays) in New Zealand

Abstract

The aim of this study was to isolate fungal endophytes from maize in New Zealand (NZ) and to select endophytes with potential to reduce insect pests and/or plant diseases. Culture methods were used to isolate 322 isolates of fungi belonging to four phyla from maize (Zea mays L.) plants. Plants were sampled over two growing seasons (2014 and 2015) in two regions of NZ. Morphological and molecular (ITS rDNA sequencing) techniques were used to identify the fungi. The most common genera recovered were Fusarium, followed by Alternaria, Trichoderma, Epicoccum, Mucor, Penicillium and Cladosoprium spp. Of the Acomycota isolates, 33 genera from 6 classes were recovered. Basidiomyctes were represented by two classes and Zycomycota by one class and a superphylum, Heterokonta, was represented with one class. To determine fungi with potential as biocontrol agents, several assay approaches were taken. Initially, most fungi were used to challenge a plant pathogen on media plates in dual culture experiments. This allowed selection of 21 promising isolates which were inoculated into maize plants by seed coating, then used in plant disease assay and a caterpillar feeding challenge assay. A final eight isolates were selected as the most promising for conferring beneficial traits on plants: Sordaria fimicola, Mucor racemosus, Mucor fragilis, Trichoderma atroviride, Penicillium brasilianum, Fusarium equiseti, Fusarium acuminatum and Fusarium proliferatum. These isolates have shown potential as BCAs against disease and/or insects in laboratory assays.