Abstract: Using fingered citron（Citrus medica L. var. sarcodactylis Swingle）and Hongkong kumquat（Fortunella hindsii Swingle）leaves from the Rutaceae family as materials，the role of CRC genes in fruit development were investigated. To achieve this，the tobacco rattle virus（TRV）to create a virus-induced gene silencing（VIGS）technology system were employed，which provided a simple and effective method for studying gene function. The silencing vector targeting the CRC gene was injected twice into the top leaves of fingered citron and Hongkong kumquat，with a time interval of 15–30 days. Between 25 and 115 days after the injections，a significant down-regulation of CmsCRC expression was observed in the neonatal leaves，neonatal flowers，and fruits of Fingered citron. The silenced plants exhibited clustered fruit shapes and an increased number of fruit fingers. The silencing effect of the CRC gene in fingered citron lasted for 25–115 days，while in Hongkong kumquat，it lasted for 25–105 days.

Key words: VIGS, fingered citron, Hongkong kumquat, CRC, fruit shape