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Four newly developed cotton mutants (M-111, M-7662, M-358 and M-218) were compared for their resistance against Cotton leaf curl virus (CLCuV) together with commercial resistant (CIM-443, CIM-482, CIM-473, FH-900 and FH-901) and susceptible (S-12) varieties by artificial inoculation through grafting and under natural field conditions. Infectivity and success of grafting were 100% in all cases. None of the grafted plants were found immune or asymptomatic. All the grafted mutants and most of their single plant progeny rows (SPPRs) showed highly resistant responses as the symptoms displayed by these mutants were milder than the commercial cultivars. Grafted mutants also had delayed disease reactions as they took more time (25-30 days) to produce disease symptoms, as compared with resistant commercial varieties that produced disease 18-22 days after inoculation. Growth of the grafted SPPRs of tested mutants was normal, which is an indication that there will be no production losses. Observations under natural infestation of whitefly showed that two SPPRs of M-11/CE and M-7662-1/2 and one resistant variety CIM-443 exhibited slight incidence of disease, while one SPPR of M-11/59 and S-12 were moderately susceptible and highly susceptible with 21% and 97.1% disease incidence, respectively. This study also showed that plants displaying more disease symptoms through grafting were easily infected under natural conditions. These results suggest that preference should be given to those plants that exhibited highly resistant responses after artificial inoculation.


Four newly developed cotton mutants (M-111, M-7662, M-358 and M-218) were compared for their resistance against Cotton leaf curl virus (CLCuV) together with commercial resistant (CIM-443, CIM-482, CIM-473, FH-900 and FH-901) and susceptible (S-12) varieties by artificial inoculation through grafting and under natural field conditions. Infectivity and success of grafting were 100% in all cases. None of the grafted plants were found immune or asymptomatic. All the grafted mutants and most of their single plant progeny rows (SPPRs) showed highly resistant responses as the symptoms displayed by these mutants were milder than the commercial cultivars. Grafted mutants also had delayed disease reactions as they took more time (25-30 days) to produce disease symptoms, as compared with resistant commercial varieties that produced disease 18-22 days after inoculation. Growth of the grafted SPPRs of tested mutants was normal, which is an indication that there will be no production losses. Observations under natural infestation of whitefly showed that two SPPRs of M-11/CE and M-7662-1/2 and one resistant variety CIM-443 exhibited slight incidence of disease, while one SPPR of M-11/59 and S-12 were moderately susceptible and highly susceptible with 21% and 97.1% disease incidence, respectively. This study also showed that plants displaying more disease symptoms through grafting were easily infected under natural conditions. These results suggest that preference should be given to those plants that exhibited highly resistant responses after artificial inoculation.