METHOD: ELISA, grafting METHOD NARR: Resistance to PLRV by chc was tested by aphid inoculation and two forms of graft testing (i.e., as a healthy scion grafted on infected D. tatula and as a healthy stock receiving an infected potion). Virus could not be detected directly by ELISA, but infection was verified by graft backtests to D. tatula. RESULTS NARR: A high level of resistance to PLRV in chc 133124 was observed. AUTHOR EXPLANATION: It is noity to the virus exists, because of the ambiguity of the definition of immunity. Resistance was shown to be to the virus rather than to the vector by use of graft inoculations.