An international team of scientists from several countries including India, the UK and the US examined the population structure of the Phytophthora infestans pathogen that caused the 2013–14 late blight epidemic in eastern and northeastern India. Their findings were published online recently in the journal Nature.The data provide new baseline information for populations of P. infestans in India. It was found that a migrant European 13_A2 genotype was responsible for the 2013–14 epidemic, replacing the existing populations. Mutations have generated substantial sub-clonal variation of which 19 were unique variants not yet reported elsewhere globally. The new A2 population is aggressive and has displaced the former populations. The pathogen is resistant to the fungicide metalaxyl, a commonly used fungicide.
The scientists say their data indicate the need for continuous surveillance to prevent the further introduction of aggressive lineages of P. infestans into the country. India has yet to begin contributions to pathogen surveillance systems, including the Asiablight program, which mirrors the objectives of the Euroblight program (http://euroblight.net/) and USAblight (http://USAblight.org). The scientists say the results of their study can now contribute to forming baseline microsatellite data for an Indiablight network or a larger Asiablight-based monitoring system in India.
The full paper can be found here, titled Large sub-clonal variation in Phytophthora infestans from recent severe late blight epidemics in India.