HISTOCHEMICAL TEST FOR PRESENCE OR ABSENCE OF CHALCONES IN ANTHERS FROM BULBS OF TULIP CV. APELDOORN PRECOOLED AT 5 °C OR KEPT AT 17 °C
Using this simple histochemical test, we found that chalcones were not present in anthers from bulbs stored at 5 °C for 12 weeks, if storage began before September 22. However, when storage began on October 3rd-5th, chalcones were detected in 4–6 weeks. Moreover, chalcones were always detected in anthers from bulbs cooled at 5 °C for 12 weeks and subsequently kept at 17 °C for one week (transport simulation). Chalcones were also first detected in anthers from bulbs kept at 17 °C (controls) after 2–8 weeks, depending on the date storage began. The earlier storage began, the later was the positive reaction.
A negative result could be used to indicate uninterrupted cooling but only for special precooled bulbs cv. Apeldoorn for which cold treatment ended during the first two weeks of December.