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

In a series of alien monosomic addition lines (AMALs; FF+1A- FF+8A) of Japa nese bunching onion (Allium fistulosum L.) with extra chromosomes from shal lot (A. cepa L. Aggregatum group), seed and pollen fertility were assessed to reveal the effect of the alien chromosomes on the fertility of the recip ient species. Data for seed fertility which were derived from three styles of pollination (open pollination, selfing, and backcrossing with A. fistulo sum) yielded considerable variations among types of the AMALs. FF+8A had hi gh seed fertility, whereas FF+3A had very low one. Pollen grains with norma l number and shape of nuclei were observed in all types of the AMALs, but p ollen fertility varied among the types. Particularly, PF+4A had high pollen fertility (approx. 80 %), whereas FF+1A expressed very low pollen fertilit y (approx. 31 %). These results indicate that alien chromosomes remarkably influence both seed and pollen fertility of the recipient species. A regres sion analysis revealed that there was no correlation between seed and polle n fertility in the AMALs. This indicates that genes related to the destinie s of seed and pollen in the AMALs are located respectively on different chr omosome of A. cepa Aggregatum group.