Using callus derived from immature embryos, regeneration of viable plants was obtained in soybean (Glycine max (L.) Merr.). Depending on the composition of the medium, regeneration occurred via embryogenesis or via organogenesis. Embryogenesis resulted when embryos were plated on Murashige and Skoog (MS) medium containing 43 μM α-naphthaleneacetic acid. In work with the cultivar Williams 82, the addition of 5.0 μM thiamine HCl increased embryogenesis from 33% to 58% of the embryos plated. Addition of 30 μM nicotinic acid to the MS medium enhanced embryogenesis further to 76%. Organogenesis was obtained when medium containing 13.3 μM 6-benzylaminopurine, 0.2 μM and α-naphthaleneacetic acid and four times the normal concentration of MS minor salts was used. Histological studies of these cultures confirmed the organogenic and embryogenic nature of the cultures, by demonstrating the formation of shoot buds and somatic embryos, respectively. Similar responses were obtained in all 54 genotypes tested in this manner. The cultures retained the ability to regenerate complete plants for at least 12 months and 12-15 subcultures. Seeds have been obtained from several regenerated plants and when grown in the field these produced normal-appearing fertile plants.

Suspension cultures of soybean were initiated from hypocotyl or cotyledon callus tissue of several soybean genotypes. When these were grown on L2 medium with 0.4 mg/liter 2,4-D several genotypes produced numerous embryoids while others produced only a few such structures. Due to internal anatomy, no embryoid developed into a complete plant. A genotype's propensity to form normal appearing embryoids was correlated with the ability to proliferate shoots at the cotyledonary node on a medium with benzylaminopurine as determined in previous testing.

Two clones of natural hybrids Acer × freemanii were propagated as scions and cuttings from trees 55-60 years old. Shoot tips from propagules were disinfected and cultured on a modified Linsmeier-Skoog (LS) medium in vitro. Elongation of shoots, rooting, and callus formation at the shoot base were dependent on the concentration of growth regulator used. The lower well-developed nodes of the typical cultured shoots could be separated and cultured individually to obtain a slow increase in propagules. When shoot tips were transferred to a medium with 0.01-0.05 μM N-phenyl-N'-l,2,3-thiadiazol-5-ylurea (thidiazuron), shoot proliferation was initiated, which could be separated into 3-10 new shoots at 6-week intervals for further proliferation or rooting. Rooted shoots were transferred to the greenhouse for further growth and subsequent transfer to the field.