# Polyembryonic or Apomictic Seeds Enable Fig Trees to Establish New Populations Without Their Pollinating Wasps, a Case Observation in Ficus gasparriniana

## TL;DR

Fig trees like Ficus gasparriniana can reproduce without their pollinating wasps by using apomixis, a process that creates seeds without fertilization.

## Contribution

This study provides the first direct evidence of apomictic reproduction in Ficus gasparriniana, revealing how fig trees can sustain populations without pollinators.

## Key findings

- Unpollinated Ficus gasparriniana seeds are formed from adventitious embryos in nucellar tissues via sporophytic apomixis.
- Apomixis in F. gasparriniana is closely linked to polyploidy, with sexual reproduction occurring at the diploid level.
- Apomixis produces enough seeds to meet the reproductive needs of F. gasparriniana.

## Abstract

Fig–wasp coevolution has been extensively studied as a fascinating case of extreme plant–insect codiversification, yet little is known about how fig trees reproduce without pollinating fig wasps. This study provides direct evidence that fig trees sustain their populations by producing polyploid and polyembryonic seeds through apomixis without fig wasp pollination. We report herein that the seeds of unpollinated Ficus gasparriniana are derived from adventitious embryos formed in the nucellar tissues and show sporophytic apomixis. Apomixis is an important reproductive mode of F. gasparriniana, which has diverse pedigree sources. Flow cytometry combined with chromosome counting and short tandem repeat typing results showed that apomixis in F. gasparriniana was closely related to polyploidy, suggesting that sexual reproduction occurred at the diploid level and apomixis occurred at the polyploid level. Thus, other polyploid Ficus species may also exhibit apomictic reproduction. This study provides essential data for advancing research on apomixis in Ficus and its role in the coevolution of fig–wasp mutualism.

Development of apomictic adventitious embry o in Ficus gasparriniana. Apomixis is a key reproductive strategy for F. gasparriniana, especially when pollination by fig wasps is limited. In the absence of pollination, F. gasparriniana produces seeds through adventitious embryos formed within the nucellar tissue, which is accompanied by polyploidization. The number of seeds produced by apomixis is sufficient to meet the reproductive needs of F. gasparriniana. This study provides the first case for understanding apomictic reproduction in Ficus.