Ontogenic development and structure of the embryo, seed, and fruit of Jatropha curcas L. (Euphorbiaceae)

- The results show that pollen grains have hexagonal and polygonal patterns.
- The pollen has a layer of exine with conspicuous verrucae.
- Formation of the early globular and cotyledonal embryo was observed 15 DPA.
- The ripening of the fruits started at 40 DPA.

Jatropha curcas L. is a species from the Euphorbiaceae family, native to Mexico and Central America. This species has been a focus of recent research because its seeds can be used as a source for biodiesel production. In this study, we evaluated the morphological characteristics of development from ovary to fruit, and from ovule to seed, as well as early stages of embryo development. The results show that pollen grains have hexagonal and polygonal patterns. At 15 days post-anthesis (DPA), the early globular and cotyledonal embryo was observed; likewise, the caruncle around the micropyle exhibited an increase of body oils in the first 15 DPA. Ripening of fruits started at 40 DPA, but the seeds' testa became hard at 35 DPA. We show in this research new insights into fruit and seed development of J. curcas, which could be useful for genetic improvement of the species in order to produce more and better oil for biodiesel production.