Ascochyta koolunga (Didymellaceae, Pleosporales) was first described in 2009 (as Phoma koolunga) and identified as the causal agent of Ascochyta blight of Pisum sativum (field pea) in South Australia. Since then A. koolunga has not been reported anywhere else in the world, and its origins and occurrence on other legume (Fabaceae) species remains unknown. Blight and leaf spot diseases of Australian native, pasture and naturalised legumes were studied to investigate a possible native origin of A. koolunga. Ascochyta koolunga was not detected on native, naturalised or pasture legumes that had leaf spot symptoms, in any of the studied regions in southern Australia, and only one isolate was recovered from P. sativum. However, we isolated five novel species in the Didymellaceae from leaf spots of Australian native legumes from commercial field pea regions throughout southern Australia. The novel species were classified on the basis of morphology and phylogenetic analyses of the internal transcribed spacer region and part of the RNA polymerase II subunit B gene region. Three of these species, Nothophoma garlbiwalawardasp. nov., Nothophoma naiawusp. nov. and Nothophoma ngayawangsp. nov., were isolated from Senna artemisioides. The other species described here are Epicoccum djirangnandirisp. nov. from Swainsona galegifolia and Neodidymelliopsis tinkyukukusp. nov. from Hardenbergia violacea. In addition, we report three new host-pathogen associations in Australia, namely Didymella pinodes on S. artemisioides and Vicia cracca, and D. lethalis on Lathyrus tingitanus. This is also the first report of Didymella prosopidis in Australia.

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Context Seeds harbour a diversity of microbes, which in some plants aid with germination and establishment. Seeds form a critical part in the lifecycle of plants and a role in many conservation and restoration activities. Aims Because this is an emerging field in seed biology, we aim to highlight the key research gaps of interest to seed on the basis of restoration and ex situ conservation. Methods We identify knowledge gaps associated with the seed endophytic microbiome of native Australian plants through undertaking a literature review. Additionally, culturing methods were used to identify the fungal seed endophytes of five native Australian species. Key results We identified a diversity of taxa within the native seed and show three taxa that are common to all study hosts. Sampling seed from additional hosts at a site and additional sites of a host species showed new fungal diversity. Our literature review showed that little information is available on native seed microbiomes and we identified four key areas where research gaps exist, linking with seed-based restoration practices. Conclusions We provide evidence that there is a complex and diverse seed microbiome within some Australian native plants and suggest ways that it could be integrated into restoration and conservation practices. Implications We propose that by taking into consideration the presence of a seed microbiome and its potential impacts on plant health, seed microbiomes could be used as one method to restore microbial diversity into an ecosystem and to contribute to the seedling microbiome and plant health at restored sites.