While diseases and ecosystem damages, caused by aerosol-borne bacteria, and viruses are widely studied, the effect of aerosolised fungal spread on human and ecosystem health is less understood.
Researchers at the Indian Institute of Technology-Madras (IIT-M) have discovered that certain species consistently affect specific types of crops and most fungal attacks on crops seem to occur during January.
The IIT-M researchers, who analysed the occurrence of fungal crop diseases in India over the past 20 years using a large set of data, found that though there appears to be no well-defined relationship between the fungal species and the type of crop affected, the analysis shows that certain species seem to consistently affect specific types of crops. It has also been observed that around 69 species of fungi have affected 39 types of crops repeatedly in two decades. Puccinia striiformis, for instance, affected the wheat crop more than 12 times in the last 20 years, according to a press release.
Researchers attribute this to three factors: Crops growing fully in January are susceptible to fungal attacks, mixing of surface air with upper boundary layer air results in the increase in bioaerosol concentration and relatively higher atmospheric humidity during the winter months. Fungal crop diseases also seem to increase with increasing temperatures, but this warrants further studies, the researchers added. Micro-organisms, often spread as suspended particles in the air, are called bioaerosols or aerobes.
While diseases and ecosystem damages, caused by aerosol-borne bacteria, and viruses are widely studied, the effect of aerosolised fungal spread on human and ecosystem health is less understood. The researchers at IIT-Madras studied the spread of fungi as aerosols and resultant crop diseases in India.
Speaking about this research, Sachin S Gunthe, associate professor, department of civil engineering, IIT-Madras, said, “Not all air-borne fungi cause diseases and eco-damage but fungal pathogens are just as prevalent and serious as bacteria and virus.”
In fact, the threat to plant species by fungal aerobes is not a new phenomenon. In the past, it has resulted in the Irish potato famine that led to starvation, economic ruin and the downfall of English government in the 19th century. Periodic fungal epidemics across life forms are being reported all over the world, with lasting impacts on health, economy and ecology.
Stressing on the importance of understanding the origin and spread of Emerging Fungal Diseases (EFD) in India, Gunthe added, “Air-borne fungi such as Magnaporthe oryzae affects paddy and Puccinia graminis affects wheat, which could have serious implications for an agrarian-based country such as India.”
“Based on the date of the alerts against crop affected, species of fungi reported, concerned states, and economic implications, we see that fungi pose a serious threat to the agricultural output in the country,” Gunthe pointed out.
We strongly believe that future increase in temperature and changes in key climate variables, including extreme weather events, will be responsible for changing patterns of fungal phenology, which would, in turn, result in damaging interaction between fungal species and crops, the report added.