免费文献传递   相关文献

Cytotaxonomical Studies on Liliaceae (s.l.): (2) Report on Chromosome Numbers and Karyotypes of 8 Species of 8 Genera from Zhejiang, China

百合科细胞分类学研究——(2)浙江产8属8种的染色体数目和核型报道


Eight species in eight genera of Liliaceae from Zhejiang were cytotaxo-
nomically studied in this work. The karyotypes of Chinese materials of these species
are mostly reported for the first time. The results are shown as follows (see Table
2-4 for chromosome parameters of them):
1. Disporum sessile D. Don Sixteen chromosomes are counted at metaphase of root-
tip cells.The Karyotype formula is 2n=16=2lm+2sm+4st+2sm+3sm+ 1sm(SAT)+2st
(Plate 1: 2-3, see Fig. 1:1 for its idiogram). The Karyotype belongs to 3B in
Stebbins’ (1971) karyotype classification, and consists of four pairs of larger chro-
mosomes (1-4) and four pairs of smaller chromosomes (5-8). One SAT-chromo-
some is situated at the sixth pair. The chromosomes range between 4.85-16.63μm.
The karyotypic constitution is similar to that of Japanese material reported by
Noguchi (1974). Chang and Hsu (1974) reported 2n=14=13st+1sm and 2n=
16=2m + 13st + 1sm for the material from Taiwan under the name of D. shimadai
Hay. (=D. sessile D. Don). Compared with our result of D. sessile, the differences
are obvious.
2. Polygonatum odoratum (Mill.) Druce PMCs diakinesis shows eleven biva-
lents, n = 11, 5 large and 6 small (Plate 2:5). The meiosis is normal. The ma-
jority of reports of this species are 2n=20, with a few 2n=22 and 30 (see Table
1). The materials from southen Siberia and the Far East in USSR are all of 2n=
20. Our result is the same as recorded by Jinno (1966) in the Japanese material
and by Li (1980) from Beijing. Ge (1987) reported 2n=20 in the culti-
vated individuals of Shandong, China, showing that both 2n=20 and 22 exist in
China.
3. Scilla scilloides (Lindl.) Druce This species has the somatic chromosome
number 2n=18 (Plate 1: 4-6, see Fig. 1:2 for its idiogram), of which two
groups of chromosomes can be recognized, i.e. the 1 st -5 th pairs of large and
the 6 th-9th pairs of small chromosomes. A distinct character of the karyotype is that
two satellites are attached to the short arms of the 1st pair of chromosomes. The degree
of asymmetry is of 3C. The karyotype formula is 2n = 18 = 2sm (SAT) + 6st + 2t+
6m + 2sm. The chromosomes range from 2.02 to 11.93 μm. The Previous counts on
the species are 2n = 16, 18, 26, 34, 35, 36 and 43 (see Table 1). The present in-
vestigation confirms Noda’s and Haga’s results. The species is considered to be of
two genomes, namely A(x = 8) and B(x = 9). Our result shows a genome compo-
sition of BB, having a pair of large SAT-chromosomes. Chang and Hsu (1974)
reported 2n = 34 from a population of Taiwan, an amphidiploid (AABB), Karyotypes
of other Chinese populations are worth further researches.
4. Tricyrtis macropoda Miq. The chromosome number of somatic cells is
2n= 26, and PMCs MII shows 13 bivalents (n= 13) (Plate 3:1-3, see Fig. 1:3
for its idiogram). The karyotype formula is 2n= 26= 6m + 10sm + 6st + 4st (or
t), which is composed of chromosomes: 4L + 22S in size. The degree of asymmetry
is of 3B. No centromeres of the 12th and 13th pairs of chromosomes were observed
at metaphase, and the chromosomes may be of st or t. Nakamura (1968) reported
2n= 26(4L+ 22S)= 2sm+ 2sm-st+ 14st-sm+ 8st for T. macropoda Miq.
and 2n= 26(4L+ 22S)= 8m+ 2sm+2sm-st+ 2st-sm+ 12st for its ssp.
affinis, both from Japan. It is clear that the major character of their karyotypes,
i. e. 4L + 22S, is consistent with that reported here. Based on the previous and
present reports, all Tricyrtis species studied are remarkably uniform in the basic
karyotype, i. e. 4L + 22S.
5. Allium macrostemon Bunge. The present observation on the root-tip cells
of the species shows 2n = 32 (Plate 3: 4-5, see Fig. 1:4 for its idiogram). The
karyotype formula is 2n (4x)= 32= 26m + 6sm, which belongs to 2B, being of
high symmetry. Except the 6th, 10th and 13th pairs of chromosomes all the
are metacentric. Chromosomes of this species are large, ranging from 5.94 to 18.06
μm. Our result agrees with Kawano’s (1975) report under the name of A. grayi
Regel ( = A. macrostemon, Wang and Tang 1980).
6. Asparagus cochinchinensis (Lour.) Merr. Ten bivalents were observed in
PMCs MI, n=10 (Plate 1: 1). The present result confirms the number of a popu-
lation of Taiwan recorded by Hsu (1971).
7. Ophiopogon japonicus (L. f.) Ker-Gawl. The species from Mt. Taogui,
Hangzhou, is found to have 2n (2x)=36=22m + 14sm (Plate 2: 1,5, see Fig.
1:5 for its idiogram) which belongs to 2B. The karyotype is composed of 2
medium-sized chromosomes with metacentric centromeres and 34 small chromosomes,
ranging from 1.34 to 4.92 μm. The populations from Mt. Tianzhu and Mt. Yuling,
Zhejiang, are found to be aneuploids at tetraploid level (2n=64-70). It is interes-
ting that Nagamatsu (1971) found the karyotypes of Japanese materials to be 2n=
67 and 68, also showing unsteady 4x karyotypes of this species. In the previous.
reports (see Table 1), the chromosome numbers of this species are mainly 2n = 72,
besides 2n = 36 recorded by Sato (1942) from Japan.
8. Liriope platyphylla Wang et Tang The somatic complement of the species
collected from Mt. Tianzhu, Hangzhou, is 2n = 36 (Plate 2: 3-4, see Fig. 1:6
for its idiogram). The karyotype is 2n(2x) = 36 = 16m + 20sm, belonging to 2B
type. The chromosomes are small except the medium-sized, 1st pair and the
range is from 1.27 to 5.19μm. The material from Mt. Yuling, Zhejiang, is found
to have a variety of chromosome numbers (2n= 60-71), as observed in Ophiopogon
japonicus. Hasegawa (1968) reported the karyotype of 2n = 72 (4x) from Japan
The 2x karyotype is first recorded.
This genus is closely related to Ophiopogon. Based on the Hasegawa’s and pre-
sent studies, all the species in these two genera are remarkably uniform in karyo-
type. Therefore, the taxonomy of the two genera is worth further researches.


全 文 :