Abstract: A full-length cDNA of FaNBS20 was isolated by homologous cloning and RT-PCR from
Fragaria × ananassa Duch.‘Jiuxiang’. Sequence analysis indicated that FaNBS20 holds a 3 573 bp open
reading frame encoding 1 190 amino acids with an estimated molecular mass of 134.5861 kD.
Bioinformatics analysis revealed that FaNBS20 contains typical domains of TIR，NB-ARC，and LRR type. FaNBS20 shares a 99% sequence similarity with the TMV resistance protein（GenBank accession No.
NC_020492）from Fragaria vesca subsp. vesca. Expression of FaNBS20 was obviously changed by the
inoculation of Colletotrichum gloeosporioides，a causal agent of strawberry anthracnose. Opposite changes
were observed in two cultivars with different susceptibility to anthracnose. In both the resistant variety
‘Sweet Charlie’and the susceptible‘Jiuxiang’，resistance to C. gloeosporioides infection was clearly
improved by spraying salicylic acid and this enhancement lasted for more than 10 d. Following the
combined treatment of SA and C. gloeosporioides，expression of FaNBS20 showed a 38-fold and 7.2-fold
increase in‘Sweet Charlie’and‘Jiuxiang’，respectively. These results indicate that the expression of
FaNBS20 may be positively correlated to strawberry resistance，and external SA can increase strawberry
resistance to anthracnose，probably，through a signaling network with FaNBS20 as an important
component.

Key words: Fragaria ×, ananassa；salicylic acid；Colletotrichum gloeosporioides；cloning；expression analysis