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

本文对浙江产的Disporum sessile， Tricyrtis macropodo，  Scilla rcilloides，Ophiopogon japoni-   cus,Liriope platyphylla和Allium macrostemon的核型作了分析，并报道了Polygonatum odoratum   和Asparagus cochinchinensis 的单倍体染色体数目。其中绝大多数为国产材料的首次记载。

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

 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.