Somatic embryogenesis and plant regeneration of maize/Tripsacum hybrids
Furini, A.; Jewell, C.
Maydica 40(2): 205-210
Hybrids from five intergeneric crosses between 5 maize inbreds and Tripsacum dactyloides (clone 65-1234) were evaluated for their ability to form long-term embryogenic and regenerable callus cultures. Embryogenic cultures and plant regeneration were obtained from all five crosses tested. Maize inbred lines CML135 and Tzil8, that in a previous study were classified as non-embryogenic, originated embryogenic and regenerable calli from the immature hybrid embryos, suggesting that the embryogenic capacity may be improved by crossing recalcitrant maize genotypes with the wild relatives. The frequency of embryogenic callus production ranged from 14.3% to 66.6% and dicamba appeared to be more suitable than 2,4-D in stimulating embryogenic callus formation, although differences in morphology were not observed between calli growing on medium supplemented with 2,4-D or dicamba. The 97 regenerated hybrid plants resembled the Tripsacum parent in vegetative morphology, and were male-sterile and tillered extensively. Mitotic analysis showed that all regenerated plants had 46 chromosomes (10 Zm + 36 Td) and C-banding of these plants showed the absence of chromosome rearrangements and of large chromosome deficiencies.