Asparagus (Asparagus officinalis L.) anthers from flowers of field-grown plants
were cultured for five genotypes, four incubation temperatures, and three sampling dates.
Treatments were evaluated for total and embryogenic callus production. Incubating
anthers at 35C was optimal for initiating embryogenic callus for three genotypes. Another
line performed best and equally well at 29 and 32C, while one was recalcitrant to
embryogenic callus formation at the temperatures evaluated. For all genotypes, almost
half of the anthers produced callus for at least one temperature treatment, hut the
percentage of these calli that was embryogenic ranged from 0% to 50%. Sampling date
affected response only for specific genotype-temperature combinations. Embryo recovery
ranged from six to 14 per callus. For the four responsive genotypes, 77% to 100% of
plantlets was haploid. Culturing anthers at several temperatures ranging from 29 to 35C,
with repeated samplings of flowers from the field, likely will allow recovery of haploid
embryos from many selections. This result will expand the germplasm base to develop
all-male asparagus hybrids.