LAUSR

A devastating complex pathological condition involving a blend of symptoms such as profuse gum exudation from the stem and slow vine decline; sudden and complete death of vines; and foliar spots progressing into blight in bottle gourd fields was observed for the first time during the year Kharif 2013–14 in Indian Punjab. Over the last five years, this problem has become widespread to emerge as one of the major limitations for bottle gourd cultivation. Through systematic studies, the pathogenesis of three simultaneously occurring syndromes in bottle gourd viz. stem gummosis and slow vine decline; quick wilting and leaf blight were deciphered and their primary etiological causes were established. Pathogenicity tests were conducted to prove Koch postulates and identification of organisms was done through morphological as well as molecular studies. The causal organism of stem gummosis and slow vine decline was established as Fusarium verticillioides (Sacc.) Nirenberg. The pathogen associated with quick wilting was identified as Fusarium oxysporum Schltdl. and the pathogen associated with leaf blight was identified as Lasiodiplodia theobromae (Pat.) Griffon & Maubl. This is the first study to decipher three different diseases caused by three distinct pathogens leading to wilt or blight type symptoms.