Methods and nucleic acids to detect and predict fungal infection of lettuce plants

An isolated nucleic acid (I), and its fragments, complements, homologs and variants are new. New isolated nucleic acid (I) is: (A) Seq. (1) of 1547 nt, or especially its fragments Seq. (2)-(132), all reproduced, and their complements; (B) sequences that hybridize to (a) under stringent conditions; (C) sequences sufficiently homologous with (a) or (b) to be their functional analogs; (D) sequences that are equivalent to (a)-(c) within the degeneracy of the genetic code; and (E) sequences of (a)-(d) modified by deletion, addition, substitution, translocation, inversion and/or insertion, provided that they remain functionally equivalent, also fragments of such sequences. Independent claims are also included for the following: (1) primers that consist of fragments of Seq. (2)-(132), for use as forward primer, or their complements, for use as reverse primer; and (2) fungal detection kit, especially for 'salad blight', that contains at least one primer of (1) and optionally instructions.