We made interspecific crosses to facilitate the introgression of desirable traits of Allium roylei into the Alliumcepa genome. After hand-pollination, 906 interspecific F1Allium cepa × A. roylei plants were obtained by in vitro culture via embryo rescue. Nuclear DNA analysis showed that 97.6% of the regenerants were interspecific F1Allium cepa × A. roylei hybrids. Genomic in situ hybridization (GISH) showed that each hybrid had 16 chromosomes, eight of which were identified as A. cepa and eight as A. roylei chromosomes.
We used artificial hybridization to study the crossability of the noble fir (Abies procera) with Manchurian fir (A. holophylla) and Caucasian fir (A. nordmanniana), and found compatibility between A. procera of North American origin and the Asian species A. holophylla as evidenced by the 14% fraction of filled seeds obtained in A. procera × A. holophylla crossing. Crossing of A. procera with the Mediterranean species A. nordmanniana failed completely, producing only empty seeds.