Longevity of Plant Pathogens in Dry Agricultural Seeds during 30 Years of Storage

The schizotrophic lifestyle of Sclerotinia sclerotiorum

Sclerotinia sclerotiorum is a cosmopolitan and typical necrotrophic phytopathogenic fungus that infects hundreds of plant species. Because no cultivars highly resistant to S. sclerotiorum are available, managing Sclerotinia disease caused by S. sclerotiorum is still challenging. However, recent studies have demonstrated that S. sclerotiorum has a beneficial effect and can live mutualistically as an endophyte in graminaceous plants, protecting the plants against major fungal diseases. An in-depth understanding of the schizotrophic lifestyle of S. sclerotiorum during interactions with plants under different environmental conditions will provide new strategies for controlling fungal disease. In this review, we summarize the pathogenesis mechanisms of S. sclerotiorum during its attack of host plants as a destructive pathogen and discuss its lifestyle as a beneficial endophytic fungus.

Fungal Pathogens and Seed Storage in the Dry State

Seeds can harbor a wide range of microorganisms, especially fungi, which can cause different sanitary problems. Seed quality and seed longevity may be drastically reduced by fungi that invade seeds before or after harvest. Seed movement can be a pathway for the spread of diseases into new areas. Some seed-associated fungi can also produce mycotoxins that may cause serious negative effects on humans, animals and the seeds themselves. Seed storage is the most efficient and widely used method for conserving plant genetic resources. The seed storage conditions used in gene banks, low temperature and low seed moisture content, increase seed longevity and are usually favorable for the survival of seed-borne mycoflora. Early detection and identification of seed fungi are essential activities to conserve high-quality seeds and to prevent pathogen dissemination. This article provides an overview of the characteristics and detection methods of seed-borne fungi, with a special focus on their potential effects on gene bank seed conservation. The review includes the following aspects: types of seed-borne fungi, paths of infection and transmission, seed health methods, fungi longevity, risk of pathogen dissemination, the effect of fungi on seed longevity and procedures to reduce the harmful effects of fungi in gene banks.