Phenotypic and Genotypic Analysis of the Population of Phytophthora infestans in Bangladesh Between 2014 and 2019

Abstract In Bangladesh, the third largest producer of potatoes in Asia, late blight, caused by Phytophthora infestans , is major constraint to production. Nevertheless, there a lack published information on pathogen population. A collection 69 isolates obtained from samples infected potato foliage collected 2018–2019 varied significantly their aggressiveness detached leaflets and tuber slices cv. Diamant. On leaflets, most were highly aggressive, colonizing more than half surface 7 days. slices, while some those 2019 less so. There was significant effect locations which both but not correlated. All A2 mating type either intermediate (38%) or resistant (62%) sensitivity fungicide metalaxyl . subset 24 all had mitochondrial DNA haplotype Ia. Samples P. (124) Bangladesh (2014–2019) genotyped 12-plex SSR. The vast majority (95%) assigned EU_13_A2, present every year collected. Numerous EU_13_A2 variants identified, many specific Bangladesh. Six (from 2017 2019) genotypes distinct with no close match known European lineages. It concluded that current population dominated aggressive lineage also dominant India Pakistan. implications this for control blight are discussed.