Clonal architectures and diversity spatial pattern of different ploidies
for Clintonia udensis in the Hualongshan Mountains
Abstract
Clintonia udensis is a perennial herb possessing two cytotypes diploid
(2n=14) and tetraploid (4n=28). In the Hualongshan Mountains, the
diploid of C. udensis primarily grows in 2450 m areas on the south
slopes, while the tetraploid grows mainly in 1900 m areas on the north
slopes. So, this intra-polyploidy is regarded as an excellent material
to study the origination, evolution and adaption of plant polyploidy.
Through field investigations and molecular genotyping, we initially
analyzed the bud bank spatial characteristics, clonal growth, and
spatial genetic structure populations between the different ploidy of C.
udensis. It found that the rhizome knot styles of C. udensis had zigzag,
C, V, and Y models between the two cytotypes. There was no dominated
clone present in the diploid or tetraploid. The clone architectures of
two ploidies were both phalanxes. However, the number of rhizome knots,
the number of buds of each rhizome knot, the ratio of rhizome branches,
and average tetraploid clones were higher than that of the diploid. The
diversity indices of the tetraploid, such as clone diversity index,
genetic distribution uniformity, and genetic diversity index, were also
slightly higher than that of the diploid. Thus, clonal reproduction
differentiation and significant genetic variations occurred between the
diploid and tetraploid of C. udensis. These two cytotypes, through seed
reproduction and clonal growth, became a facultative clonal species and
maintained its survival stability and reproduction. During the
evolutionary process, the tetraploid of C. udensis with higher clonal
diversity and genetic diversity responded and adapted to new
surroundings that different from the ancestral diploid in the
Hualongshan Mountains.