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bioRxiv · 10.1101/2023.08.03.551682

Cross-pollination is more important than gibberellin application in the germination of the everlasting flowers of Janeirona carrasqueira (morphotype of Comanthera bisulcata)

de Azevedo, M. L.·Oliveira, M. N. S. d.·Rech, A. R.·Barbosa, J. C.·Gorgens, E. B.·Machado, E. L. M.·Pereira, I. M.
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Abstract

The "sempre-vivas" are plants known as "everlasting flowers" because they have inflorescences that retain the appearance of living structures even after being harvested and dried. Given their ornamental potential, some species are widely exploited commercially, and their production occurs almost exclusively through extractivism. However, data on their pollination, reproduction, and germination are limited. Extractivism is an activity of great importance for the residents of the Espinhaco Meridional municipalities, and research is essential for establishing plans and proposals for the management of these native species. Given this scenario, we studied the pollinators and the importance of cross- and autogamy for reproductive success of Janeirona carrasqueira (morphotype of Comanthera bisulcata (Korn) L.R. Parra & Giul), commercially collected in Diamantina, Minas Gerais. We also evaluated germination and the influence of the exogenous application of gibberellin (GA3) on seeds. Pollinators were observed during the flowering period in beds cultivated with this species in the native Campo Rupestre area of Diamantina, Minas Gerais. The inflorescences of the species were collected from two different environments: one isolated from pollinating insects (inside the greenhouse), and the other open in the presence of pollinators. The seeds were removed from the flower heads and subjected to exogenous application of gibberellin (0-control and 500 ppm). The flowers showed a generalist pollination strategy, including visitors who collected pollen and nectar as well as those who exclusively collected nectar. For germination, the most influential factor was cross-pollination and not gibberellin application. We conclude that the pollination system represents a determining mechanism and is a very important factor to be considered in management plans aimed at species conservation. Highlights- Comanthera bisulcata employs a generalist pollination strategy. - The pollination system is a crucial mechanism for germination. - Cross-pollination is more important than gibberellin application - Reproduction is a crucial aspect to be taken into account in the management plans of the species.

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de Azevedo, M. L., Oliveira, M. N. S. d., Rech, A. R., Barbosa, J. C., Gorgens, E. B., Machado, E. L. M., Pereira, I. M.. 2023-08-05. Cross-pollination is more important than gibberellin application in the germination of the everlasting flowers of Janeirona carrasqueira (morphotype of Comanthera bisulcata). https://doi.org/10.1101/2023.08.03.551682

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