Using upland cotton GhCLA1 as marker gene, tobacco rattle virus induced genes silencing(TRV-VIGS) was established in cotton. A gene fragment of TRV subgenomic RNA2 was amplified by reverse transcription-polymerase chain reaction(RT-PCR) in root, stem and leaf of cotton, demonstrating the virus can spread into various organs. The TRV induced silencing of CLA1 gene was further tested in 34 different cotton varieties(lines) originated from several ecological regions of China. The results showed that CLA1 could...