Apm. Rodriguez et Hy. Wetzstein, THE EFFECT OF AUXIN TYPE AND CONCENTRATION ON PECAN (CARYA-ILLINOINENSIS) SOMATIC EMBRYO MORPHOLOGY AND SUBSEQUENT CONVERSION INTO PLANTS, Plant cell reports, 13(11), 1994, pp. 607-611
Embryogenic cultures were initiated from immature pecan zygotic embryo
s. Explants were induced for one week on Woody Plant Medium with eithe
r alpha-naphthaleneacetic acid or 2,4-dichlorophenoxyacetic acid at 2,
6 or 12 mg/l, then subcultured monthly to fresh basal medium. Observa
tions were made on callus production, embryo formation, and embryo mor
phology. Somatic embryo morphology and overall callus proliferation we
re affected by auxin type. Callus proliferation was less extensive and
more somatic embryos resembling zygotic embryos were obtained from cu
ltures initiated with alpha-naphthaleneacetic acid than with 2,4-dichl
orophenoxyacetic acid. Repetitive somatic embryogenesis was obtained i
n all auxin treatments. Conversion into plantlets was affected by soma
tic embryo morphology in that embryos with poorly developed apices exh
ibited lower percentages of conversion than those with well developed
single or multiple apices, Consequently although more embryos were obt
ained with 2,4-dichlorophenoxyacetic acid, naphthaleneacetic acid was
the superior auxin for production of somatic embryos more likely to co
nvert into plants.