Chromosomes of Temnocephala minor,an ectosymbiotic turbellarian on Australian crayfish found in Kagoshima Prefecture,with karyological notes on exotic turbellarians found in Japan

Records of exotic turbellarian species found in Japan are reviewed from taxonomic and karyological viewpoints. Temnocephala minor Haswell, 1888, an ectocommensal on a freshwater crayfish of Australia, was found from culture ponds of Cherax tenuimanus (introduced from W. Australia) in Kagoshima Prefecture. T. minor had the chromosome number of 2x = 18 (2sm + 2m + 2m + 2sm + 2m + 2m + 2m + 2sm + 2m). The following 3 species of exotic freshwater triclads were recorded from tanks and ponds used for tropical fish culture: Dugesia austroasiatica Kawakatsu, 1985 (2x = 16), Dugesia tigrina (Girard, 1850) (2x = 16) and Rhodax? sp. (3x = 24; 3x = 24 &; 3x + 1LB + 1SB = 25 + 1SB). The following 3 species of exotic terrestrial triclads were recorded: Bipalium nobile Kawakatsu et Makino, 1982 (2x = 10), Bipalium kewense Moseley, 1878 (2x = 18), and Platydemus manokwari de Beauchamp, 1962 (n = 6, 2x = 12). An extensive occurrence of P. manokwari in the Southwest Islands of Japan may be due to an unexpected introduction of the animal in very recent years.     

风毛菊属5种植物的核型分析

采用常规压片法,对风毛菊属(Saussurea)5种植物的染色体数目和核型类型进行分析。结果表明:大耳叶风毛菊(S.macrota)核型公式为2n=2x=26=10m+12sm+4st,属2A型;长梗风毛菊(S.dolichopoda)核型公式为2n=2x=26=14m+8sm+4st,属2A型;川陕风毛菊(S.licentiana)核型公式为2n=2x=28=12m+16sm,属2B型;杨叶风毛菊(S.populifolia)核型公式为2n=2x=28=6m+18sm+4st,属2B型;尾叶风毛菊(S.caudata)核型公式为2n=2x=30=14m+14sm+2st,属2A型。这5种风毛菊属植物中,除大耳叶风毛菊染色体数目和核型类型与前人报道的一致外,其余4种植物的染色体数目和核型类型均为首次报道,并在川陕风毛菊中发现1对B染色体。     

风毛菊属6种植物的核型分析

采用常规压片技术对分布于横断山区菊科(Compositae)风毛菊属(Saussurea DC.)的6种植物进行染色体数目和核型分析。结果表明:尖苞雪莲（S.polycolea var.acutisquama）核型公式为:2n=2x=32=20m+12sm,属2B型;球花雪莲核（S.globosa）型公式为:2n=2x=34=16m+18sm,属2B型;重齿风毛菊(S.katochaete)核型公式为:2n=2x=32=8m+18sm+6st,属3B型;柱茎风毛菊(S.columnaris)核型公式为:2n=2x=32=24m+8sm,属2B型;禾叶风毛菊(S.graminea)核型公式为:2n=2x=28=8m+18sm+2st,属3B型;长毛风毛菊(S.hieracioides)核型公式为:2n=2x=32=12m+16sm+4st,属2B型。6个种染色体中均未发现随体。其中尖苞雪莲和柱茎风毛菊染色体为首次报道。     

角堇与大花三色堇染色体核型分析

以2份角堇与4份大花三色堇自交系为试验材料,采用染色体常规压片方法,观察和分析了它们的细胞染色体数目、相对长度、平均臂比等核型指标,以明确两种植物细胞学特点,为分类以及育种提供理论依据。结果表明:(1)2份角堇自交系染色体数目均为2n=2x=26,染色体基数为x=13,染色体核型公式分别为2n=2x=26=8m+12sm+6st、2n=2x=26=4m+16sm+6st,核型不对称系数为67.20%~70.10%,核型分类均属于3B。(2)4份大花三色堇自交系均为四倍体,其中2份(EYO-1-2-1-4、DSRFY-1-1-2)染色体数目为44,核型公式为2n=4x=44=4m+16sm+6st、2n=4x=44=16m+24sm+4st;2份(G10-1-3-1-4、XXL-YB-1-1-1-1)染色体数目为48,核型公式分别为2n=4x=48=8m+20sm+20st、2n=4x=48=4m+36sm+8st,核型不对称系数为66.74%~71.77%,核型分类属于2B、3B。     

Comparative karyomorphology and interrelationships ofSelaginella in Japan

Karyomorphological comparisons were made of 16 native and cultivated species ofSelaginella in Japan. The somatic chromosome numbers are 2n=16 inS. boninensis; 2n=18 inS. doederleinii, S. helvetica, S. limbata, S. lutchuensis, S. nipponica, S. selaginoides, S. tama-montana, andS. uncinata; 2n=20 inS. biformis, S. involvens, S. moellendorffii, S. remotifolia, andS. tamariscina; 2n=30 inS. rossii; and 2n=32 inS. heterostachys. The interphase nuclei of all species examined are uniformly assigned to the simple chromocenter type. The metaphase karyotype of 2n=16 (x=8) is 8 m (=median centromeric chromosomes)+8(st+t)(=subterminal and terminal). The group of the species having 2n=18 (x=9) is heterogeneous karyomorphologically: The karyotype ofS. nipponica is 2n=18=6 m+12(st+t),S. tama-montana 10 m+2 sm(=submedian)+6(st+t), andS. uncinata 6 m+7 sm+5(st+t). Although the remaining five species have the common karyotype 8 m+4 sm+6(st+t), the values of mean chromosome length are variable. Another group of the specles having 2n=20 (x=10) is homogeneous, since all species have the same karyotypes 8 m+4 sm+8(st+t) and have similar chromosome size. The karyotype of 2n=30 is 12 m+6 sm+12(st+t) and is suggested to be a triploid of x=10, and 2n=32=16m+16(st+t), a tetraploid of x=8. Thus, three kinds of basic chromosome numbers, x=8, 9, 10 are present in JapaneseSelaginella examined, and their karyomorphological relationships are discussed.     

Karyomorphological studies onWoodwardia sensu lato of Japan

Karyomorphological comparisons were made of five species of JapaneseWoodwardia. There were no marked differences at interphase and prophase among the five species.Woodwardia japonica, W. prolifera, andW. unigemmata were diploid with 2n=68 and the formulas of their metaphase karyotypes uniformly 4m(median centromeric chromosomes)+12sm(submedian)+52(st+t)(subterminal and terminal).Woodwardia orientalis was tetraploid with 2n=136 and 8m+24sm+104(st+t), and the ratio of each chromosomal type to total complement was identical to that of three diploid species. These four species had several characteristics in common:x=34, the longest chromosome of sm, and a mean chromosome length over 3.0 μm. AlthoughWoodwardia orientalis showed some similarity toW. prolifera, it seems to be an allotetraploid which originated by chromosome doubling of a hybrid ofW. prolifera and a diploid species as yet karyomorphologically unknown.Woodwardia kempii was tetraploid with 2n=124 and 8m+24sm+92(st+t), and differed from the others in havingx=31, the longest chromosomes of t, and a mean chromosome length under 3.0 μm. This species has been classified as an independent genus,Chieniopteris, and our karyomorphological study supports this treatment.     

6种野生草莓的核型分析

以五叶草莓等6种野生草莓为试材,采用常规压片法对其进行了核型分析。结果表明,6种野生草莓的核型公式分别为:五叶草莓2n=2x=14=12m+2sm、黄毛草莓2n=2x=14=8m+6sm、绿色草莓2n=2x=14=10m+2sm+2st、东北草莓2n=2x=14=8m+6sm、森林草莓2n=2x=14=6m+8sm、西南草莓2n=4x=28=16m+12sm,6种野生草莓的核型类型均为"2A"型。供试6种野生草莓的进化顺序可能为:五叶草莓、绿色草莓、东北草莓、黄毛草莓、西南草莓、森林草莓。     

武汉地区野豌豆属3种植物的染色体研究

本文报道了武汉地区野豌豆属3种植物的染色体数目及核型,结果如下:窄叶野豌豆为2n=2x=12=2sm+2st(SAT)+8st;小巢菜为2n=2x=14=10m+2sm(SAT)+2st;四籽野豌豆为2n=2x=14=4m+2sm(SAT)+8sm。本文还对野豌豆属染色体进化的有关问题进行了讨论。     

两种羽叶菊属植物(菊科:千里光族)的细胞学研究及其系统学意义

该研究首次报道了滇羽叶菊和台湾刘寄奴的染色体数据。结果表明:两者的染色体数量都为48,核型公式均为2n=2x=36m+10sm+2st,与前人报道的刻裂羽叶菊的核型稍有不同。两者的染色体形态均由大到小逐渐变化,核型二型性不明显,但前者染色体明显比后者大。这说明羽叶菊属染色体基数确实应为x=24,且染色体大小在种间有较大差异。细胞学证据表明,该属与蒲儿根属中染色体基数为x=24的类群以及狗舌草属确实近缘。     

六种犁头尖属植物(天南星科)的核型研究

报道了 6种 8个居群犁头尖属 ( Typhonium Schott)植物的核型 ,其结果如下 :( 1 )独角莲 ( T.gigan-teum)北京居群 2 n=4 x=5 2 =4 4m+ 7sm+ 1 st;( 2 )鞭檐犁头尖 ( T.flagelliforme)金平居群 2 n=3x=2 4 =3m+ 9sm( 4 SAT) + 1 2 st,河内居群 2 n=4 x=32 =7m+ 2 0 st+ 4sm+ 1 t;( 3)单籽犁头尖 ( T. calcicolum)西畴居群2 n=4 x=5 2 =2 1 sm+ 2 3m( 5 SAT) + 8st;( 4 )犁头尖 ( T.blumei)重庆居群 2 n=4 x=5 2 =4 0 m( 1 SAT) + 1 2 sm( 3SAT) ;( 5 )马蹄犁头尖 ( T.trilobatum)西双版纳居群 2 n=2 x=1 8=4 sm( 2 SAT) + 1 2 m+ 2 st,河内居群 2 n=2 x=1 8=2 st+ 9m+ 7sm;( 6 )金慈菇 ( T. roxburgii)个旧居群 2 n=2 x=1 8=8sm+ 1 0 m( 2 SAT)。其中鞭檐犁头尖 2 n=2 4、32 ,金慈菇 2 n=1 8均为首次报道 ,同时分析讨论了本属植物染色体基数和倍性的多样性及其可能的原始基数     

五种苏铁属植物的核形态

报道了苏铁属（Cycas L.)5种植物的染色体数目和核型,除多歧苏铁外,其他种均为首次报道。5个种的体细胞中期染色体核型公式分别为：滇南苏铁C.diannanensis K(2n)=2x=22=2m 4sm 4st 12T;潭清苏铁C.tanqingii K(2n)=2x=22=2m 8sm 2st 10T;多歧苏的Cmultipinnata K(2n)=2x=22=4m 8st 2st 8T;巴兰萨苏铁C.balansae K(2n)=2x=xx=2m 4sm 6st 10T。石山苏铁C.miquelii K(2n)=22=2m 6sm(1SAT) 4st 10T;核型均属于3B型。本研究结果支持苏铁属植物的核型从不对称进化的观点;同时,支持将巴兰萨苏铁和石山苏铁归入攀枝花苏铁组的台湾苏铁亚组的观点。     

凤仙花近缘种间核型分析与叶表皮微形态研究

为探究凤仙花近缘种植物的细胞学和微形态学方面的亲缘关系,该文选取荔波凤仙花(Impatiens liboensis)及近缘种赤水凤仙花(I.chishuiensis)和管茎凤仙花(I.tubulosa)的根尖和叶表皮为实验材料,采用体细胞染色体常规压片法和叶表皮光学显微镜观察法对凤仙花近缘种植物进行染色体及叶表皮特征研...     

Karyomorphological study of the Spiraea japonica complex (Rosaceae)

Reported in this paper is a karyomorphological study on one natural population of each of eight varieties in theSpiraea japonica complex. The interphase and mitotic prophase can be classified into the simple chromocenter type and the proximal type, respectively. The metaphase karyotypes of the eight varieties were formulated as follows:S. japonica var.japonica: 2n=18=14m+2sm+2st;S. japonica var.acuta: 2n=18=11m+4sm+3st;S. japonica var.incisa: 2n=18=12m+4sm+2st;S. japonica var.stellaris: 2n=18=15m+1sm+2st;S. japonica var.acuminata: 2n=18=14m+2sm+2st;S. japonica var.ovalifolia: 2n=18=10m+2sm+2st+4t;S. japonica var.glabra: 2n=18=10m+4sm+4st;S. japonica var.fortunei: 2n=36=17m+16sm+3st. Karyomorphological study reveals that the chromosome numbers within the complex are stable, and that karyomorphological divergence between the varieties lies mainly in chromosome size and organization. Based on the karyomorphological data and geographical distribution of the complex, the differentiation pattern as well as evolutionary mechanism of the complex is evaluated.     

Cytogenetics,biogeography and biology of Santolina ageratifolia Barnades ex Asso (Asteraceae: Anthemideae)

Santolina ageratifolia Barnades ex Asso is a natural autohexaploid (2n = 6x = 54, 54 + 1B), endemic to Teruel Province, Spain and inhabits a substrate derived from sandstone, red limolite and quartzite. Three chromosome formulae are found: 30m + 12sm + 12st, present in 52% of the descendants (52 metaphase), 24m + 5m‐1sm + 18sm + 6st in 39% of the descendants (39 metaphase) and 24m + 5m‐1sm + 18sm + 6st + 1B in 9% of the descendants (9 metaphase). Chiasmata are mostly interstitial rather than terminal, giving rise to the formation of cruciform structures. The predominance of bivalent configurations in the meiosis and the exclusively bivalent formation in four individuals indicate that this species has a strong tendency towards diploidization. Secondary association of bivalents is observed in the number of 2, 4–6 chromosomes associated, the average being 4.21 ± 1.20 chromosomes. The variation in the chromosomal characteristics suggests chromosome translocation and/or inversions. This species is partially sterile, with a mean pollen fertility of 40.56% and a mean fructification of 34.24%. The frequencies of multivalents and pollen fertility have a strongly significant effect on fructification percentage. Phenotypic variation in habits is not correlated with karyotype characteristics. The cytogeography of the polyploid taxa of the Santolina rosmarinifolia aggregate is discussed. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 797–807.     

中国西南地区6种植物的核型研究及其系统学意义

采用植物细胞学研究方法对主要采自中国西南地区横断山的6种植物:扁核木(Prinsepia utilis)、小叶金露梅(Potentilla parvifolia)、峨眉繁缕(Stellaria omeiensis)、金铁锁(Psammosilene tunicoides)、山卷耳(Cerastium pusillum)和独尾草(Eremurus chinensis)进行染色体数目和核型研究。研究表明:(1)6个种的核型公式和不对称性如下:扁核木2n=2x=30=1M+20m+9sm,2A;小叶金露梅2n=2x=28=21m+7sm,2B;峨眉繁缕2n=8x=72=1M+71m,1B;金铁锁在同居群下有倍性变化,2n=2x=14=14m,1A和2n=4x=28=28m,1A;山卷耳2n=2x=24=24m(2sat),1A;独尾草2n=2x=14=2m+2sm+8st+2t,4B。(2)讨论了染色体资料在这些物种分类和系统上的意义,支持扁核木为李亚科下的扁核木属;位于委陵菜属木本系的小叶金露梅主要以二倍体和四倍体为主,而草本系的委陵菜属植物多为多倍体。(3)该研究首次报道峨眉繁缕为八倍体,是繁缕属发现的最高倍性的物种;对比金铁锁属与蝇子草属的染色体研究发现,金铁锁属可能是由它们的共同祖先通过非整倍化产生;该研究首次发现山卷耳存在染色体数目2n=24的情况,且有1对随体;独尾草的研究进一步证明该物种可能为二型核。     

我国入侵植物薇甘菊(菊科)的细胞学研究

为了解入侵植物薇甘菊(Mikania micrantha)的细胞学特性,研究了薇甘菊在我国广东东南部4居群和台湾2居群的染色体数目和染色体形态。结果表明,所有居群的薇甘菊染色体数目均为2n=36,第一对染色体为近中部着丝粒染色体,其长臂中部具有次缢痕,显著大于其余染色体。广东深圳大学和深圳水库居群的核型公式为2n=20m+14sm+2st;广东汕头、阳江和台湾屏东居群为2n=22m+12sm+2st;台湾宜兰居群为2n=18m+16sm+2st。此前有报道薇甘菊深圳大学居群的染色体数目为2n=38,推断为制片过程中第一对染色体从次缢痕处断裂而导致的计数错误。因此,薇甘菊虽存在非整倍性和多倍性变化,但在广东东南部和台湾的入侵居群中目前仅发现基于x=18的二倍体(2n=36),该种在这些地区的成功入侵与多倍性无关。     

东北蒿属艾组12种植物核型研究

报道东北蒿属艾组12种植物的染色体数及核型资料,结果如下：宽叶山蒿（Artemisia stolonifera (Maixm.)Komar.)2n=4x=36=28m 4sm(4SAT) 4st(4SAT);野艾蒿（A.lavandulaefolia DC)2n=2x=50=40m 4sm 6st(6SAT); 矮蒿（A.lancea Van.)2n=2x=16=10m 4sm 2st;蒙古蒿（A.mongolica (fisch.ex Bess.)Nakai]2n=2x=16=14m 2st;红足蒿（A.rubripes Nakai)2n=2x=16=14m 2st;歧茎蒿（A.igniaria Maixm.)2n=2x=34=28m 2sm 4st(4SAT);柳叶蒿（A.integrifolia Linn.)2n=4x=36=20m 12sm 4st;线叶蒿（A.subula 4st(4SAT);柳叶蒿（A.integrifolia Linn.)2n＝4x=36=20m 12sm 4st;线叶蒿（A.subulata Nakai)2n=2x=16=14m 2st;高岭蒿（A.brachyphylla Kitam.)2n=2x=18=14m 2sm 2st;林文稿[A.uiridissima(Komar.)Pamp.]2n=2x=18=14m 4sm;奄癌（A.keiskeana Miq.)2n=2x=18=16m 2sm;阴地蒿（A.sylvatica Maxim.)2n=2x=16=14m 2sm,核型对称性野艾蒿（A.lavandulaefolia)为2B型,其余均为2A型,依据核型资料对个别种的演化 分类进行了初步探讨。     

Karyomorphology of the genusLycopodium sensu stricto and relationships among species

Karyomorphological comparisons were made of six species of JapaneseLycopodium sensu stricto. There were no marked differences at interphase and prophase among the six species.Lycopodium annotinum had 2n=68 and the formula of its metaphase karyotype was 18m(median centromeric chromosomes)+12sm(submedian)+12st(subterminal)+26t(terminal).Lycopodium casuarinoides had 2n=68=16m+10sm+18st+24t,L. clavatum 2n=68=22m+12sm+18st+16t, andL. obscurum 2n=68=10m+22sm+20st+16t. Each of these species, which belong to different sections, displayed several karyomorphological differences. Among themL. casuarinoides differs largely from the others in its mean chromosome length, ratio of the longest chromosome to the shortest, and frequency of m+sm chromosomes. BothLycopodium complanatum andL. nikoense, belonging to sectionComplanata, had a common karyotype 2n=46=10m+12sm+18st+6t. This section displayed a low differentiation in its karyotype. In the wholeLycopodium s.s., the ratios of m+sm in a complement varied from 38 to 50%, being higher among pteridophytes.     

国产8种蜘蛛抱蛋属植物的核型研究

首次报道了8种蜘蛛抱蛋属植物的核型,其中6种的染色体数目为首次报道。结果如下：峨边蜘蛛抱蛋A．ebianensis,2n=2x=36=18m+2sm(2sat)十16st;盈江蜘蛛抱蛋A．yingjiangensis,2n=2x=36=14m+6sm(2sat)十16st;海南蜘蛛抱蛋A．hainanensis,2n=2x=36=20m(2sat)十14st十2t;石山蜘蛛抱蛋A．saxicola,2n=2x=36=16m十4sm(2sat)十16st;糙果蜘蛛抱蛋A．muricata,2n=2x=36=18m+2sm(2sat)十16st;啮边蜘蛛抱蛋A．marginella,2n=2x=38=22m+4sm(2sat)十12st;西林蜘蛛抱蛋A．xilin-ensis,2n=4x=76=48m(4sat)十2sm+26st;十字蜘蛛抱蛋A．cruciformis,2n=4x=76=46m(4sat)十12sm十18st。核型类型都为2C型。首次在中国发现了A．cruciformis和A．xilinensis的野生四倍体。根据外部形态性状及已有的38种植物的核型资料分析,认为该属染色体的原始基数可能为x=18,核型向对称性增强的方向演化,其主要表现在中部着丝粒染色体数目的增多,这种演化趋势似与其花部结构的进化密切相关。关键词 蜘蛛抱蛋属;染色体数目;核型;进化     

Saussurea pseudograminea sp. nov. (Asteraceae) from the Qinghai–Tibetan plateau,China

Morphological characteristics, as well as ultrastructure of pollen grains, chromosome numbers and karyotype analysis have been used to establish a new species of Saussurea from the Qinghai–Tibetan plateau. The new species, Saussurea pseudograminea Y. F. Wang, G. Z. Du et Y. S. Lian is easily distinguished from the similar S. graminea Dunn by having 2–3 capitula, involucre 0.7–1.2 cm in diameter, smaller pollen grains, pollen surface with larger and denser spines, achenes 4.0–5.5 mm long, 32 chromosomes, and a karyotype formula 2n = 2x = 32 = 18m + 10sm + 4st, whereas S. graminea has solitary capitula, involucre 1.2–2.0 cm in diameter, larger pollen grains, pollen surface with smaller and sparser spines, achenes 3–4 mm long, 28 chromosomes and a karyotype formula 2n = 2x = 28 = 6m + 20sm + 2st. The new species is distributed in Dianzhangou, Awanchang, and Gamaliang mountain regions of Maqu county in Gansu province.