Fertility of alien monosomic addition lines of Japanese bunching onion (Allium fistulosum L.) with extra chromosomes from shallot (A. cepa L. aggregatum group)

Abstract

In a series of alien monosomic addition lines (AMALs; FF+1A-FF+8A) of Japanese bunching onion (Allium fistulosum L.) with extra chromosomes from shallot (A. cepa L. Aggregatum group), seed and pollen fertility were assessed to reveal the effect of the alien chromosomes on the fertility of the recipient species. Data for seed fertility which were derived from three styles of pollination (open pollination, selling, and backcrossing with A. fistulosum) yielded considerable variations among types of the AMALs. FF+8A had high seed fertility, whereas FF+3A had very low one. Pollen grains with normal number and shape of nuclei were observed in all types of the AMALs, but pollen fertility varied among the types. Particularly, FF+4A had high pollen fertility (approx. 80 %), whereas FF+1A expressed very low pollen fertility (approx. 31%). These results indicate that alien chromosomes remarkably influence both seed and pollen fertility of the recipient species. A regression analysis revealed that there was no correlation between seed and pollen fertility in the AMALs. This indicates that genes related to the destinies of seed and pollen in the AMALs are located respectively on different chromosome of A. cepa Aggregatum group.