BOTRYTIS CINEREA INFECTION IN PISTILLATE AND HERMAPHRODITE STRAWBERRY FLOWERS.
To investigate this hypothesis four families, which were segregating for flower type, were studied. Two secondary flowers were removed from 50 plants in each family. These were placed with their pedicels through holes in sheets of perforated polystyrene which were floating on water in plastic trays. The flowers were then sprayed with a suspension containing 105 conidia per ml. of B. cinerea. The trays were covered with glass sheets and placed in an incubator at 10°C.
Necrosis caused by B. cinerea infection was recorded over a period of 25 days using an arbitrary scale. Statistically significant differences were detected between the pistillate and hermaphrodite flowers after 5, 10, 15, 20 and 25 days; in each case the pistillate flowers had a lower mean score. The mean number of days before necrosis was observed in the receptacle was also greater for the pistillate flowers.
Examinations revealed that infection occurred on anthers, when present, and also stigmas. Subsequently necrosis spread from the anther, down the filament, and into the base of the receptacle via the sepal. With stigmatic infection the disease spread into the style but did not enter the receptacle via this route.