M. Peng et Dj. Wolyn, Improved callus formation and plant regeneration for shed microspore culture in asparagus (Asparagus officinalis L.), PL CELL REP, 18(11), 1999, pp. 954-958
To establish an efficient asparagus microspore culture system, experiments
were conducted to investigate the effects of medium components period of co
ld pretreatment for flower buds, and period of anther co-culture on culture
response. All factors affected the frequency of asparagus microspore divis
ion and the yields of microspore-derived calli. The best results were obtai
ned by pretreating genotype G459 newer buds at 4 degrees C for 7-9 days, co
-culturing anthers with shed microspores for 14 days and including 6% sucro
se, 2 mg l(-1) alpha-naphthaleneacetic acid and 1 mg l(-1) N-6-benzylaminop
urine in the culture medium. After 4 days of culture, most shed microspores
contained starch-like bodies and died. The 2% of shed microspores lacking
these structures divided to produce microcalli. For the best treatments in
the different experiments, about 140 calli per 100 anthers were recovered.
Cultured on four different regeneration media, 19.6-21% and 3.9-8.0% of mic
rospore-derived calli produced shoots and embryos, respectively, and ultima
tely plantlets, among which 49% were haploid, 34% diploid, 4% triploid and
11% tetraploid.