兰州百合的核型分析

报道了兰州百合的染色体核型,其核型公式为2n=2X=24=2m(2SAT) 2sm 6st 14t,属于3A型,核型不对称性系数(As.K%)为81.37%。其中第一对染色体的短臂上具有居间随体。     

贵州三种臭蛙的核型,C-带,银带比较

比较了贵州产绿臭蛙(Odorrana margartae),云南臭蛙(O.andersonii),花臭蛙(O.schmackeri)三种臭蛙的核型,C-带,银带,讨论了三种臭蛙的核型,C-带,银带的异同与形态差异的关系。在核型特征和C-带带型特征上,绿臭蛙与花臭蛙之间的差异最大,绿臭蛙与云南臭蛙的差异次之,云南臭蛙与花臭蛙之间的差异较小;在银带带型特征上,绿臭蛙的标准Ag-NORs位于第9号染色体长臂;云南臭蛙与花臭蛙的标准Ag-NORs位于第10号染色体长臂。     

甘肃中华蟾蜍和中国林蛙核型的初步研究

经酵母汁、秋水仙素对甘肃中华蟾蜍(Bufo gargarizans cantor)和中国林蛙(Rana chensinensis)处理后,取骨髓细胞制作染色体标本,对其核型分别进行了初步研究分析。结果表明,中华蟾蜍的二倍体染色体数目为2n=22,由6对大型染色体和5对小型染色体组成,染色体简式为:2n=9m 2sm;中国林蛙的二倍体染色体数目为2n=24,由5对大型染色体和7对小型染色体组成,染色体简式为:2n=5m 5sm 1st 1t。这可用于不同地域同类物种的鉴定和分类。     

万寿竹六个居群的核型研究

本文研究了在云南境内的万寿竹Disporum cantoniense (Lour．)Merr．从滇东南经滇中到滇西 北不同居群间的核型变异。该种的染色体数目较为稳定，2n=14，没有观察到不同数目的变异。六个 居群的不对称性均属于3B型，但各个居群的核型结构表现出一定的差异，核型间随体位置和数目的不 同以及同源染色体的杂合性是居群间变异的主要特征，这种种内不同居群间核型的变异或许与该种的地理分布及生境有一定的相关性。     

两种亚洲百合的核型分析

利用染色体常规压片法,对亚洲百合杂种系的两种百合进行了核型分析,结果表明:克得利亚(Cordelia)的染色体核型公式2n=2X=24=2m+4sm(4SAT)+10st(2SAT)+8t(2SAT),核型不对称系数(As.K%)为76.33%.黑美人(Negro)的染色体核型公式2n=2X=24=2m+4sm(2SAT)+8st(2SAT)+10t,核型不对称系数(As.K%)为79.60%.核型类型都属于3B型.     

云南四倍体多星韭二倍体化的细胞学研究

采用常规制片技术,对苍山、鸡足山华严寺和昆明长虫山3个四倍体多星韭种群进行了减数分裂观察和核型分析.结果表明：核型分析反映出云南西北部地区的苍山、鸡足山四倍体多星韭的核型对称性比中部地区昆明长虫山种群高;减数分裂观察表明四倍体多星韭的28条染色体在减数分裂前期I时,两两联会成为14个二价体,后期I配对的染色体分离比较同步,没有观察到提前或延后分离以及染色体桥或染色体片段;对四倍体减数分裂过程的观察支持核型分析将28条染色体成2地配成14组,而不是成4地配成7组的结果,为四倍体多星韭的二倍体化提供了直接的细胞学证据.     

滇蜀豹子花核型及其变异研究

本文详细报道了滇蜀豹子花的核型，发现居群中存在两种细胞型，即A型和B型。A型参考核型为2n = 24＝2m(2SAT)+2sm+8st(4SAT)+12t(2SAT)，其第3号两条同源染色体长臂均无居间随体：B型参考核型为2n=24＝2m(2SAT)+2sm+8st(2SAT)+12t(3SAT)+0—1b，其第3号一条同源染色体长臂紧靠着丝点处有一大而明显的居间随体，而另一条同源染色体则无，构成明显的3号染色体的结构杂合性。统计表明，居群中二者的比例近似为1A；2B。研究还发现了大量的体细胞染色体结构变异核型，表明滇蜀豹子花核型尚未趋于稳定，还处于强烈分化之中，高频率的体细胞染色体结构变异是其种内分化不可忽视的一种进化要素。     

鄱阳湖三角帆蚌(Hyriopsis cumingii)核型研究

运用PHA(8μg/g体重)和秋水仙素(1-2μg/g体重)腹腔内注射,空气干燥法,以鳃组织和性腺组织为材料,对采自鄱阳湖的三角帆蚌的染色体核型进行分析研究.结果表明,三角帆蚌的二倍体数目为2n=38,核型为5m+5sm+5st+4t.     

斯氏按蚊的有丝分裂染色体核型、G带的初步研究

采用加热干燥涂片法对斯氏按蚊的有丝分裂染色体核型、G带进行了研究．结果表明：斯氏按蚊染色体数目为2n=6，属XY型，全部为中着丝粒染色体；Y染色体存在中着丝粒和端着丝粒染色体两种形态：在G带中，两对常染色体在着丝粒附近颜色较深，性染色体X、Y的一条臂全部深染，另一臂分别呈现4条和3条带；雄蚊共有21条带．研究中还观察到了染色体多态现象．     

四川及其邻近地区一些植物的细胞学研究(一)

From standpoint of floristic division,  Sichuan is located in the middle part of Eastern Asiatic Region (Takhtajan 1978) or is the area where Sino-Himalayan Forest Subkingdom and Sino-Japan Forest Subkingdom meet (wu 1979).  Here exist many so- called Arcto-Tertiary elements and newly originated species or races.  In order to bring the light the origin and differentiation of Eastern Asiatic elements,  cytological investi- gation on plants of this region are very significant.  The materials of the following 5 species were collected on Mt.  Emei in Sichuan Province.  Voucher specimens are kept in CDBI.       1.  Toricellia angulata  Oliver var. intermedia (Harms) Hu       PMC meiotic examination revealed n = 12 at diakinesis (Pl. I fig. 9)       Toricellia,  consisting of 2 spp.,  is endemic to Eastern Asiatic Region.  Based on our result along with the report of Toricellia tiliifolia (Wall.) DC. (2n=24) by Kuro- sawa (1977),  we argue that the basic chromosome number of Toricellia is 12.  Many authors,  such as Airy-Shaw (1973),  Dahlgren (1975,  1977),  Takhtajan (1969,  1980), Thorne (1983),  have adopted Hu’s (1934) treatment erecting it as a monotypic family Toricelliaceae.  Its systematic position,  whether closer to Cornaceae than to Araliaceae or vice versa,  has been in dispute.  Cytologically it seems closer to Araliaceae,  as shown anatomically (Lodriguez 1971),  because the basic chromosome number of Cornaceae s. 1. is x=11,  9,  8 (Kurosawa 1977),  whereas that of Araliaceae is 12 (Raven 1975).       2.  Cardiocrinum giganteum  (Wall.) Makino       Somatic chromosome number,  2n=24 was determined from root-tip cells (Ph. I. fig. 8).       Cardiocrinum (Endl.) Lindl.,  consisting of 3 spp.,  is endemic to Eastern Asiatic Region.  C. giganteum (Wall.) Makino is distributed from Himalayan region to S. W. China.  The present report is in accord with the number reported by Kurosawa (1966) who got the material from Darjeeling of India.  However the karyotype of the present plant is slightly different from that given by Kurosawa.  In the present material,  the satellites of the 1st. pair of chromosomes and the short arms of llst.  pair of chromoso- mes are visibly longer than those of Kurosawa’s drawing (fig. 1,  2) The plants from Yunnan,  Sichuan and Hubei Provinces,  named as C. giganteum var. yunnanense (Leit- chtlin ex Elwes) Stearn,  differ slightly from those of Himalayan region also in outer morphological characters.  The taxon needs both cytological and taxonomical further studies.       3.  Disporum cantoniense  (Lour.) Merr.       PMC meiotic examination revealed n=8 at diakinesis (Pl. I. fig. 6)       This species is widely distributed from Himalayan region through Indo-China to our Taiwan Province and Indonesia. Three cytotypes (2n=14,  16,  30) were reported for the taxon including its variety,  var. parviflorum (Wall) Hara,  by various authors (Ha- segawa 1932,  Mehra and Pathamia 1960,  Kurosawa 1966,  1971 Mehra and Sachdeva 1976a).  Some authors consider D. pullum Salisb. and D. calcaratum D. Don as synonyms of D. cantoniense. So D. cantoniense may be a species aggregate with different extreme races.  Sen (1973a,  b.) reports that the somatic chromosome numbers of D. pullum and D. calcaratum from Eastern Himalayan region are 14,  16,  28,  30,  32.  He also discovered that chromosome alterations in species of Disporum involve not only the num- ber but the structure as well.  He found that in species of Liliaceae where the reproduc- tion is mainly vegetative,  polysomaty often occurs.  In China we have not only D. can- toniense and D. calcaratum but also D. brachystomon Wang et Tang which is similar to D. cantoniense var. parviflorum (Wall.) Hara.  These taxa need further critical studies.      4.  Paris fargesii Franch.      PMC meiotic examination revealed n=5+2B (Voucher no. 112) or n=5 (Voucher no. 62) at MI and AI (Pl. I. fig. 1. 4. 5.).  This is the first report for the species.  A bridge and a fragment were also observed at AI.      Paris polyphylla Smith is extraordinarily polymorphic species.  Hara (1969) re- gards all chinese extreme forms,  such as P. fargesii Franch.,  P. violacea Lévl.,  P. pube- scens (Hand. -Mzt.) Wang et Tang,  etc. as infraspecific taxa of P. polyphylla.  Need- less to say,  the various races of P. polyphylla Smith in China need further critical stu- dies and are good material for further study to understand the speciation.      5.  Reineckia carnea(Andr.) Kunth       Reineckia is a monotypic genus endemic to Eastern Asiatic Region.  In the present material somatic chromosome number in root-tip cells is determined as 2n=38 (Pl. I. fig. 7).  According to the terminology defined by Levan et al.,  the karyotype formula is 2n=28 m+10 sm.  The length of chromosomes varies from 14.28 μ to 5.5 μ. The idiogram given here (fig. 3) is nearly the same as that presented by Hsu et Li (1984). The same number has been previously reported by several authors,  Noguchi (1936),  Satô (1942), Therman (1956).  The karyotype is relatively symmetrical (2B,  accorling to the classi-fication of stebbins 1971) in accord with the opinion of Therman (1956).