One of the things we are troubleshooting in the lab right now is pollen tube trafficking through the style. We would like to know how many pollen tubes make their way into the ovary. Ravi Palanivelu at the University of Arizona suggested we try a semi-in vitro system. Here is the experiment: we pollinated pistils with pollen containing a genetic marker that turns pollen blue (LAT52:GUS). After 1 hour, we cut the pistil at the carpal shoulders, and laid it on an agar plate. We then incubated the plate overnight, and stained the tubes blue (for protocols, see here).
Counting the number of pollen tubes is going to take a bit more