Bc. Li et Dj. Wolyn, TEMPERATURE AND GENOTYPE AFFECT ASPARAGUS SOMATIC EMBRYOGENESIS, In vitro cellular & developmental biology. Plant, 32(3), 1996, pp. 136-139
Calluses from five asparagus genotypes, G14, G32, G171, G203, and G447
and hybrid Jersey Giant (JG) were incubated at three-temperature regi
mes (24, 27, and 30 degrees C) on embryo induction medium to assess so
matic embryo development and conversion to plantlets. The calluses fro
m three genotypes (G14, G32, and G171) were not responsive, failing to
produce somatic embryos at any temperature regime. For three responsi
ve genotypes (G203, G447, and JG), both incubation temperature and gen
otype significantly affected the numbers of somatic embryos produced.
The calluses produced the most and the least numbers of total, bipolar
, and globular embryos when incubated at 27 degrees C and 24 degrees C
, respectively. When incubated at 27 degrees C, G203 produced the high
est numbers of total and globular embryos, 178 g(-1) callus and 142 g(
-1) callus, respectively, while G447 produced the highest number of bi
polar embryos, 77 g(-1) callus. Incubation temperature but not genotyp
e significantly affected the conversion of somatic embryos to plantlet
s. The somatic embryos recovered from the three responsive genotypes i
ncubated at 27 degrees C also converted to plantlets at the highest fr
equencies, 60-63% of the bipolar embryos and 42-43% of the globular em
bryos converted to plantlets, while the somatic embryos recovered from
the calluses incubated at 24 degrees C converted to plantlets at the
lowest frequencies.