Abstract

                                Powdery mildew of grapes is one of the most criticalwidespread and destructive diseases worldwide, and it causes yield reduction upto 65-80 percent. In the present study, the survey was conducted in different districts of Tamil Nadu and percent disease index wasassessed. The preliminary identification of the pathogen was madethrough phase contrast microscopic observation such as color, shape,and size of the conidia were measured as well as scanning electron microscopy was also used to study the morphometric characters of E.necator. Further,the isolates were confirmed through PCR analysis which yielded an amplicon size of 470 bp while using the specific primers (cyt b forward and cyt b reverse) targeting the E.necator.

Key words : Grapes; Powdery mildew;Erysiphenecator[Schw.Burr]; Survey; Morphology; Molecular characterization