Ex-situ propagation of Anacamptis pyramidalis (L.) from an agroecological perspective

Abstract

The pyramidal orchid (Anacamptis pyramidalis) in Lebanon is facing random collection and potential extinction risks. To address this conservation concern, we conducted a study to investigate the impact of different agroecological treatments, including substrate type, mycorrhizal application, and mother bulb separation, on the growth and flowering characteristics of the orchid. The primary aim was to propose effective methods for ex-situ propagation of this endangered species. Various substrates were employed, including Own-soil, Pinebark, Pinebark-Peat (1/1 ratio), and Peat-Sand (1/1 ratio). Son bulbs were planted separately (SB) or combined with mother bulbs from the previous season (SB+MB), with or without mycorrhizal application (M: Yes and M: No). The selection of treatments was based on the natural requirements of the Pyramidal orchid in the wild state. The trial was conducted over a two-year period. The control treatment (Own-soil/SB+MB/M: No) yielded the highest plant length (37cm), width of the longest leaf (1.6cm), length of the longest leaf (17cm), width of the shortest leaf (1.4cm), dorsal sepal length (0.9cm), labellum length (0.9cm), petal length (0.9cm), and length of bulbs (3cm). Mother bulb separation resulted in enhanced growth for all indicators except bulb length and width. Mycorrhiza application improved all indicators, except the width of the shortest leaf and lateral sepal length. The combination of mycorrhizal treatment with mother bulb separation yielded the most significant improvements across all indicators compared to the control. Notably, in the Peat+Sand/SB/M: Yes treatment, there was a substantial increase in the width of the longest leaf (by 0.5cm) and the length of the longest leaf (by 3cm) compared to the control. Integrating the three studied factors provided a suitable ex-situ conditioning approach for the orchid, surpassing in-situ conditions. This study provides valuable insights into effective strategies for the conservation and ex-situ propagation of the pyramidal orchid in Lebanon.