Since the domestication of plants, pathogenic fungi have consistently threatened crop production, evolving genetically to develop increased virulence under various selection pressures. Understanding their evolutionary trends is crucial for predicting and designing control measures against future disease outbreaks. This paper reviews the evolution of fungal pathogens from natural habitats to agricultural settings, focusing on eight significant phytopathogens: Pyricularia oryzae, Botrytis cinerea, Puccinia spp., Fusarium graminearum, F. oxysporum, Blumeria graminis, Zymoseptoria tritici, and Colletotrichum spp. Also, we explore the mechanism used to understand evolutionary trends in these fungi. The studied pathogens have evolved in agroecosystems through either (1) introduction from elsewhere; or (2) local origins involving co-evolution with host plants, host shifts, or genetic variations within existing strains. Genetic variation, generated via sexual recombination and various asexual mechanisms, often drives pathogen evolution. While sexual recombination is rare and mainly occurs at the center of origin of the pathogen, asexual mechanisms such as mutations, parasexual recombination, horizontal gene or chromosome transfer, and chromosomal structural variations are predominant. Farming practices like mono-cropping resistant cultivars and prolonged use of fungicides with the same mode of action can drive the emergence of new pathotypes. Furthermore, host range does not necessarily impact pathogen adaptation and evolution. Although halting pathogen evolution is impractical, its pace can be slowed by managing selective pressures, optimizing farming practices, and enforcing quarantine regulations. The study of pathogen evolution has been transformed by advancements in molecular biology, genomics, and bioinformatics, utilizing methods like next-generation sequencing, comparative genomics, transcriptomics and population genomics. However, continuous research remains essential to monitor how pathogens evolve over time and to develop proactive strategies that mitigate their impact on agriculture.

The MV X-Press Pearl maritime incident had a profound impact on the marine and coastal ecosystems along the west coast of Sri Lanka. Considerable quantities of plastic pellets, specifically nurdles or pellets measuring less than 5 mm and estimated at 1680 tonnes, were released into the Indian Ocean. A notable portion of these plastic pellets/primary microplastics (MPs), has the potential to degrade into secondary MPs. The objective of this study was to investigate and understand the degradation process of plastic pellets into secondary MPs under the extreme conditions of fire and exposure to chemicals during the MV X-Press Pearl maritime disaster. Beach sand samples were collected from 40 locations along the affected west coast of Sri Lanka, at both mean sea level and the berm. An additional 20 samples were collected for a background study covering the entire coastline of Sri Lanka. The Wet Peroxide Oxidation (WPO) process was employed to separate microplastics, and observations of secondary MP quantities were recorded. Fourier Transform Infra-Red Spectroscopic (FTIR) analysis was carried out to identify functional groups of MPs. The variance in average values of secondary MPs at mean sea level (large MPs (i.e. size > 0. 5 mm) = 33 ± 56 items per 1 mm² and total MPs (i.e. observed through microscope under 40× magnification) = 61 ± 66 items per 1 mm²) and the berm (large = 61 ± 154 items per 1 mm² and total MPs = 106 ± 165 items per 1 mm²) suggested significant dispersal of large quantities of MPs to other areas in the Indian Ocean with oceanic currents. The baseline average value of secondary total MPs in other coastal areas of the country was approximately 53 ± 66 items per 1 mm². The positive correlation between large and total secondary MPs and plastic pellets pollution index indicates that a considerable amount of plastic pellets were degraded into secondary MPs within 6 to 8 days after the accident, under the influence of nitric acid and heat/fire. These secondary MPs are mainly composed of low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE), as identified by FTIR observations. Consequently, these lightweight polymers have the potential to spread across a wider region, posing a severe environmental threat on a global scale as a transoceanic marine pollutant.

Since the domestication of plants, pathogenic fungi have consistently threatened crop production, evolving genetically to develop increased virulence under various selection pressures. Understanding their evolutionary trends is crucial for predicting and designing control measures against future disease outbreaks. This paper reviews the evolution of fungal pathogens from natural habitats to agricultural settings, focusing on eight significant phytopathogens: Pyricularia oryzae, Botrytis cinerea, Puccinia spp., Fusarium graminearum, F. oxysporum, Blumeria graminis, Zymoseptoria tritici, and Colletotrichum spp. Also, we explore the mechanism used to understand evolutionary trends in these fungi. The studied pathogens have evolved in agroecosystems through either (1) introduction from elsewhere or (2) local origins involving co-evolution with host plants, host shifts, or genetic variations within existing strains. Genetic variation, generated via sexual recombination and various asexual mechanisms, often drives pathogen evolution. While sexual recombination is rare and mainly occurs at the center of origin of the pathogen, asexual mechanisms such as mutations, parasexual recombination, horizontal gene or chromosome transfer, and chromosomal structural variations are predominant. Farming practices like mono-cropping resistant cultivars and prolonged use of fungicides with the same mode of action can drive the emergence of new pathotypes. Furthermore, host range does not necessarily impact pathogen adaptation and evolution. Although halting pathogen evolution is impractical, its pace can be slowed by managing selective pressures, optimizing farming practices, and enforcing quarantine regulations. The study of pathogen evolution has been transformed by advancements in molecular biology, genomics, and bioinformatics, utilizing methods like next-generation sequencing, comparative genomics, transcriptomics and population genomics. However, continuous research remains essential to monitor how pathogens evolve over time and to develop proactive strategies that mitigate their impact on agriculture.