Fecha de publicación: 17/08/2016 Fuente: WIPO "tobacco agriculture" The invention discloses a method for determining phytophthora nicotianae virulence through in-vitro shoots. The method comprises the following steps of 1 preparing phytophthora nicotianae sclertium; 2, preparing in-vitro shoots; 3, performing inoculation; 4, determining and evaluating the virulence. The method is simple, convenient and easy to implement, the phytophthora nicotianae virulence is expressed stably, the repeatability is good, results are reliable, and the phytophthora nicotianae virulence and virulence intensity can be accurately reflected; in actual operation, determination can be performed in batches, the method has the advantages of being small in occupied space, saving the labor cost, and shortening the experimental period, and therefore the method is suitable for being applied and popularized.