Reproductive biology of Butia capitata (Arecaceae) under cultivation - indicators for the domestication of a threatened fruit tree

• Published in: Scientia horticulturae 2022-10, Vol.304, p.111297, Article 111297
• Main Authors: Dias, Wlly Polliana Antunes, Lopes, Paulo Sergio Nascimento, Fonseca, Rúbia Santos, Ribeiro, Leonardo Monteiro, Gonçalves, Armando Pego, Ribeiro, Bruno Alencar Pestana
• Format: Article
• Language: English
• Subjects: Palms; Pollen; Pollination; Reproductive phenology; Reproductive system; Xenogamy
• ISSN: 0304-4238; 1879-1018
• DOI: 10.1016/j.scienta.2022.111297

•Cultivation allow the production of butia capitata fruits in the natural off-season.•Protandria (sterile period from one to six days) helps to prevent self-pollination.•Cross- and open-pollination are the most efficient reproductive systems.•Refrigeration and freezing preserve pollen viability for 180 days.•Artificial pollination is promising for improving the productivity of orchards. Butia capitata is a netropical palm that has ecological and economic importance but is threatened by deforestation. The domestication of the species would contribute to its conservation and to income generation. However, there are gaps in knowledge about the phenology, floral biology and pollination of B. capitata and information on these topics is crucial to support breeding programs. We describe here the phenology and reproductive biology of B. capitata under cultivation and evaluated the storage potential of its pollen. Phenological and morphological evaluations of inflorescence and fruit development were carried out during both the rainy and dry seasons, the dynamics of anthesis and stigmatic receptivity were monitored and the reproductive system was experimentally evaluated. Pollen grain storage under different conditions was investigated for six months. Inflorescence emission were more rapid in the rainy season, with greater numbers of infructescences as well as fruit weight. Cross-pollination was predominant due to protandry, with a sterile period from one to six days. Cross- and open- pollination are the most efficient reproductive systems (46 and 47% fruting, respectively). Fruit fixation does not occur under spontaneous self-pollination or apomixis, while artificial self-pollination induces only a small fruiting rate. Pollen grain viability was maintained for 180 days under both refrigeration (4 °C) and freezing (-20 °C) conditions, but was less than 30 days under natural environmental conditions. The cultivation allows the production in the off-season of natural populations and pollen grain storage and artificial cross-pollination are promising possibilities for increasing the productivity of B. capitata orchards.