stiga receptivity test

[dx-zhang]

Dear lister,
I used the benzidine and H2O2 methods (Dafni, 1992) to test the stigma receptivity but failed. In a Bauhinia species with wet stigmas, the solution didn't give any reaction with the stigmas in any of the stages, while in several Magnoliaceae genera, they gave strong reaction to stigmas from bud to withering flowers. Besides the artificial cross-pollination method, do you have any other suggestions?
Thank you in advance.

Dianxiang Zhang