Summary - The reproduction of Radopholus similis isolates from different
origins and hosts was compared in carrot disk cultures at different
temperatures. At 15°C, only the isolates collected from ornamental plants in
Europe reproduced. The greatest fecundity was observed at 25°C. The
reproduction factor (final population/initial population: Pf/Pi) ranked the
isolates in similar order for four of the temperatures studied (15, 20, 25
and 30°C). When carrot discs at 28°C were inoculated with single females of
isolates selected from those with different reproductive factors, this
ranking was confirmed. This suggests that reproduction is controlled by
intrinsic isolate characteristics which are not influenced by temperature.
Isolates with most reproduction had a greater percentage of reproductive
females than isolates with less reproduction, associated with a high ratio
of females : males and a high proportion of females in the total production.
The mean offspring per productive female was similar for high and low