Abstract
—Calli were induced from anthers of
Populus simonii
×
P. nigra.
Haploid plants were then regenerated
from the callus and multiplied efficiently by culturing leaf explants. The presence of both haploid and diploid
cells in the same plant revealed spontaneous chromosome doubling in haploid cells. The haploid plants
were transformed with the
nptII
gene by
Agrobacterium
-mediated method using leaf explants, and five independent
kanamycin-resistant lines were obtained, with a transformation frequency more than 6%. Further PCR
test indicated that the exogenous
betA
gene was transferred into these kanamycin-resistant lines, which were
still haploid. Thus, the efficient tissue culture system and transformation of haploid poplar plants were achieved.
Our study will contribute to forest improvement via the haploid culture and transgenic technology.