The mode of seed formation in Allium senescens and two Korean Allium species

The genus Allium includes several important vegetable and ornamental species, and is an economically important crop. The objective of this study was to determine the mode of reproduction in A. senescens L. (2n=6x= 48) and two Allium species collected in Korea. Chromosome numbers of embryo sac mother cells (EMCs) at diplotene of meiosis were 2n = 48 and unreduced in A. senescens. However, normal sexual reproduction was observed at diplotene in both A. senescens var. minor (2n = 2x= 16) and A. nutans L. (2n=4x= 32). Parthenogenetic embryogenesis also occurred in A. senescens at high frequencies among the three Allium species. Antipodal embryos in A. nutans were formed in unpollinated flowers. Normal seeds were not formed in flowers of A. senescens that had been emasculated and kept in sealed conditions. However, normal seeds were formed in the flowers that were pollinated 2 days after anthesis. In conclusion, diplospory, parthenogenesis, and pseudogamy occur in A. senescens.