Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

First report of Pantoea ananatis causing fruitlet blight of Nagpur mandarin (Citrus reticulata) in India.

Abstract

Since April 2016, new symptoms have been observed on fruitlets of Nagpur mandarin orange (Citrus reticulata) in commercial groves in the Nagpur and Amravati districts of the Vidarbha region of Maharashtra state in India. The disease was observed in crops which had blossomed in January-February. Affected tissue first had an irregular water-soaked appearance that quickly turned dark brown or black and became sunken. Over time, the blackened fruitlet became dry, wrinkled and often dropped off. Symptoms did not advance into the shoots. Nearly 30% of the trees were affected with over 20% of fruitlets (12-20 mm in diameter) on those trees blighted. The causal pathogen was isolated and identified as Pantoea ananatis based on morphological, biochemical, molecular (rDNA gene sequence) and pathogenicity analyses. This is thought to be the first report of P. ananatis causing fruitlet blight of Nagpur mandarin in India. This disease may threaten the Nagpur mandarin production system if effective management strategies are not implemented.