Abstract Apomixis has been suggested to result from the asynchronous gene expression of duplicated genes governing plant reproduction. The similarity of embryological stages and gene expression patterns observed during sexual and apomictic processes, and appearance of apomictic stages (e.g., aposporous initials) at different stages of ovule development support this hypothesis. We evaluated this hypothesis by assessing temporal variation during microsporogenesis, microgametogenesis, megasporogenesis and megagametogenesis in Cenchrus ciliaris L. This study was conducted using individuals of C. ciliaris with two distinct modes of reproduction viz., facultative apomictic or sexual. Inflorescences were classified into five stages based on morphological indicators. Variation in the configuration and developmental timing of gametophytes of facultative sexual and apomictic plants was studied at these five stages using the high-throughput technique of whole-mount confocal microscopy. Asynchrony in development of early reproductive stages in apomictic plants, as observed by presence of greater number of embryological stages in florets of the same inflorescence, is prominent in comparison to sexual plants. Such inconsistency was greater in female than in male gametophyte development. Stages like 3-nucleated sexual embryo sac and aposporous proembryo could also be observed. This supports the hypothesis that apomixis could be the result of de-regulated sexual reproductive pathway.
Journal articles from the Grassland Society of Southern Africa (GSSA) African Journal of Range and Forage Science as well as related articles and reports from throughout the southern African region.