A dsRNA molecule comprising i) a first strand comprising a sequence identical to at least 18 contiguous nucleotides of a fungus or oomycete saccharopine dehydrogenase gene and ii) a second strand comprising a sequence substantially complementary to the first strand, wherein the fungus or oomycete gene is selected from the group consisting of: a) a polynucleotide comprising a sequence as set forth in SEQ ID N0: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43; b) a polynucleotide encoding a polypeptide having a sequence as set forth in SEQ ID N0: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 25, 28, 30, 32, 34, 36, 38, 40, 42, 44; c) a polynucleotide having at least 70% sequence identity, preferably at least 80%, more preferably at least 90%, even more preferably at least 95% to a polynucleotide having a sequence as set forth in SEQ ID N0: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43; d) a polynucleotide encoding a polypeptide having at least 70% sequence identity, preferably at least 80%, more preferably at least 90%, even more preferably at least 95%, to a polypeptide having a sequence as set forth in SEQ ID N0: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44; e) a polynucleotide hybridizing under stringent conditions to a polynucleotide having a sequence as set forth in SEQ ID N0: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43; and f) a polynucleotide hybridizing under stringent conditions to a polynucleotide encoding a polypeptide having at least 70% sequence identity to a polypeptide having a sequence as set forth in SEQ ID N0: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44. a) a polynucleotide comprising a sequence as set forth in SEQ ID N0: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43; b) a polynucleotide encoding a polypeptide having a sequence as set forth in SEQ ID N0: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 25, 28, 30, 32, 34, 36, 38, 40, 42, 44; c) a polynucleotide having at least 70% sequence identity, preferably at least 80%, more preferably at least 90%, even more preferably at least 95% to a polynucleotide having a sequence as set forth in SEQ ID N0: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43; d) a polynucleotide encoding a polypeptide having at least 70% sequence identity, preferably at least 80%, more preferably at least 90%, even more preferably at least 95%, to a polypeptide having a sequence as set forth in SEQ ID N0: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44; e) a polynucleotide hybridizing under stringent conditions to a polynucleotide having a sequence as set forth in SEQ ID N0: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43; and f) a polynucleotide hybridizing under stringent conditions to a polynucleotide encoding a polypeptide having at least 70% sequence identity to a polypeptide having a sequence as set forth in SEQ ID N0: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44.