作 者 ：Fu Cheng-Xin, Liu Ming-Yuan
期 刊 ：植物分类学报 1987年 3期
Keywords:Adenopora, Chromosomal number, Karyotype, Heilongjiang,
Abstract:
This paper is a cytological part of biosystematic studies on Adenophora Fisch. in
Heilongjiang, China. Chromosomal numbers and karyotypes of 10 spp. and 1 var. are reported.
The results are summarized in Table 1. The chromosomal numbers and karyotypes of 6 spp.
and 1 var. are first reported, including tetraploid species (2n=68) (A. pereskiifolia var. alterni-
folia, A. amurica and A. gmelinii). The basic number of chromosomes in the genus is mainly
17 (x=17), but that of A. trachelioides and A. remotiflora (2n=36) is 18 (x=18), an unique
one in the genus. The karyotypes of all the species examined are relatively uniform, which
means that they are derived from a common ancestral type. The chromosomes are smaller,
varying between 2-4 μm. The majority of chromosomes are m and sm ones. And a pair
of sat-chromosomes and a pair of st chromosomes are always present. The centromeric terminali-
zation value of chromosomes is 57.5-61.9%, showing higher symmetry of karyotypes in the
genus. The karyotype of A. tetraphylla (2n=34) is the most symmetrical among these species.
Based on its morphological characters and distribution, the species may be considered as a re-
latively primitive member of the genus.
The results show two revolutionary trends in karyotypes of the genus: number variation
(including polyploidy and aneuploidy) and structural variation. The polyploidy is one of
the principal patterns of speciation in the genus. Combined with the other characters, these spe-
cies are taxonomically discussed, and two new taxa (A. amurica Fu et Liu and A. pereskiifolia
ssp. alternifolia (Fuh ex Y. Z. Zhao) Fu et Liu) are confirmed. A. trachelioides and A. re-
motiflora (both 2n=36) with obvious petioles seems more advanced than the other species (2n
34).