The aim of this study is to determine the endogenous hormone activities of Gibberellic acid (GA) in compatible (Intraspecific = ISP) and incompatible pollination (Intergeneric = IGP). The study was designed using Himantoglossum robertianum for ISP experiments and both Himantoglossum robertianum and Orchis italica for IGP experiments. To conduct the IGP experiments, pollinia from O. italica were applied to the flower stigmas of H. robertianum using needles. Ovaries with stigma from both types of pollination were collected over a period of 10 days, and quantitative hormone analyses were performed using LC-MS/MS.
The results showed that GA was not detected in the ISP experiments. Similarly, GA was absent in the IGP tests from days 1 to 6, but it was found on days 7, 8, 9, and 10, with values increasing each day. This study is the first to determine the endogenous ovary-stigma GA levels in the post-pollination process of orchid IGP, and its significance was discussed. According to statistical analysis, there is a significant difference between nearly all values. It is understood that additional histological and embryological studies are needed to understand the reason for the very high activity, particularly on days 9 and 10.
Aybeke, Mehmet. (2025). Gibberellic Acid is Active Only in Orchid Cross-Pollination. Osmaniye Korkut Ata Üniversitesi Fen Bilimleri Enstitüsü Dergisi. 8. 533-542. 10.47495/okufbed.1452135.
Source: Research Gate