中国西南六种广义拂子茅属( 禾本科) 植物的染色体数目

广义拂子茅属( Calamagrostis) 是一个世界温带广布的大属, 有些作者又分为拂子茅属和野青茅属, 但近期的研究表明处理为一个属较为合适。中国共有37 种广义拂子茅属植物, 但至今没有任何染色体的研究。本文报道了其中产于中国西南6 种野青茅的染色体数目, 其中Deyeuxia petelotii 4 个居群, D1 diffusa, D1 moupinensis, D1 nivicola 和D1f lavens 各一个居群都是四倍体( 2n= 4x= 28) , D1 neglecta 为六倍体( 2n= 6x= 42) 。根据广义拂子茅属植物染色体倍性特征, 该属植物中至今未发现二倍体, 四倍体是该属中倍性最低和最普遍的, 广义拂子茅属的演化很可能是在四倍体的水平上进行的。由于以上几个四倍体种均是狭域分布的类群, 所以可能是由四倍体的祖先隔离分化形成的。     

禾本科广义拂子茅属的叶表皮形态研究

禾本科广义拂子茅属Calamagrostis Adans. s.l.是广布于全球温带和热带亚热带高山的一个大属, 常分为拂子茅属Calamagrostis Adans. s.s.和野青茅属Deyeuxia Beauv.。对国产5种拂子茅属和26种、1变种野青茅属植物在光镜下进行了叶表皮特征的观察。发现广义拂子茅属植物的叶表皮特征为典型的狐茅型, 很多结构在种间有丰富的变异式样, 如脉间长细胞形状、大小和细胞壁的厚度与弯曲程度, 短细胞形状和分布式样, 硅质体形状和分布式样, 气孔形状和分布式样, 以及刺毛形态和分布式样等。在国产种类中首次发现微乳突结构, 在很多种类中发现刺毛硅质化现象。用UPGMA对15个叶表皮性状进行分析, 结果分为两大支: 具加厚的长细胞、密集分布的短细胞和(或)刺毛以及刺毛硅质化的种类聚为一支; 具薄壁的长细胞、较稀疏的短细胞和(或)刺毛以及刺毛不发生硅质化的种类聚为另一支。这种分异与广义拂子茅属的属下系统相关性不大, 但与种的海拔分布有关。前一支的种类大多生长于高海拔(2600 m以上)地区, 而后一支的种类则大多生长在低海拔(2600 m以下)地区。     

中国野青茅属(禾本科)一些种类的修订(Ⅱ)

在标本室研究和野外考察的基础上,对中国野青茅属Deyeuxia的一些种类进行了修订.归并了2个名称,即将Deyeuxia sikangensis Keng并入D. scabrescens (Griseb.) Munro ex Duthie作为异名; 将D. levipes Keng并入D. nivicola Hook. f. 作为异名.确认了D. dispar L. Liou和D. agrostioides L. Liou是两个未合格发表的名称,将前者归并于D. scabrescens,后者归并于D. diffusa Keng.     

中国野青茅属(禾本科)一些种类的修订

在标本室研究和野外考察的基础上,对中国野青茅属的一些种类进行了修订。首次归并了5个类群,即将Deyeuxia pulchella var． laxa P．C．Kuo et S．L. Lu,D．gyirongensis P．C. Kuo et S．L．Lu,Calamagrostis megalantha Keng ex Keng f.并入 D. pulchella (Griseb.)Hook．f.作为异名;将D．venusta Keng,Calamagrostis longiflora Keng ex Keng f．并入D.flavens Keng作为异名;并确认D. compacta Munro ex Hook．f.与D.holciformis (Jaub．et Spach．)Bor是同一种。     

中国野青茅属(禾本科)一些种类的修订(II)(英文)

在标本室研究和野外考察的基础上,对中国野青茅属Deyeuxia的一些种类进行了修订。归并了2个名称,即将Deyeuxia sikangensis Keng并入D. scabrescens (Griseb.) Munro ex Duthie作为异名; 将D.levipes Keng并入D. nivicola Hook. f. 作为异名。确认了D. dispar L. Liou和D. agrostioides L. Liou是两个未合格发表的名称,将前者归并于D. scabrescens,后者归并于D. diffusa Keng。     

六种中国苔类植物的染色体数目

报道了6种中国苔类植物配子体茎尖分生组织有丝分裂中期的染色体数目(1)皱叶耳叶苔,n=9;(2)双齿异萼苔,n=9;(3)卵叶羽苔,n=9;(4)丛生光萼苔日本变种,n=8;(5)密叶光萼苔,n=8;(6)格氏合叶苔,n=9。其中丛生光萼苔日本变种的染色体数目为首次报道,双齿异萼苔的染色体数目为国内首次报道。     

五种中国秋海棠属植物的染色体数目

对 5种中国秋海棠属 (BegoniaL .)植物的体细胞染色体数目进行了报道 ,分别为 :小叶秋海棠B parvulaL啨ｖｌ.etVant .2n =2 8;石生秋海棠B lithophilaC .Y .Wu 2n =2 4 ;木里秋海棠B muliensisY櫣 2n =2 4 ;蕺叶秋海棠B limprichtiiIrmsch .2n =2 2 ;以及二室组sectionPlatycentrum的一个未知种B sp . 2n =2 0。     

中国部分木兰科植物染色体数目

作者观察了我国木兰科7属30种植物的染色体数目,其中23种为首次报道．     

Taxonomic significance of leaf anatomy of Aniselytron (Poaceae) as an evidence to support its generic validity against Calamagrostis s. l.

A comparative study of leaf anatomy on Aniselytron Merr. and Calamagrostis Adans. s. l. was conducted to review the systematic status of Aniselytron Merr. Calamagrostis s. l. exhibits wide variation in many features, but basic leaf structures of the genus remain constant: absence of a midrib-keel; median and large vascular bundles are central, with double sheaths, accompanied by girders both adaxially and abaxially; prickles have a bulbous base and are not sunken; the abaxial epidermal cells are short and wide and relatively thick-walled. Aniselytron differs from Calamagrostis s. l. in: midrib-keel is present, consisting of a large central bundle with small ones on either side; all vascular bundles are abaxially situated, with abaxial girders only, parenchyma takes the place of the adaxial sclerenchyma; the bases of the prickles are sunken and are not bulbous; the abaxial epidermal cells are tall and thin-walled. These distinct anatomical features, in combination with the differences in spikelet structure and habitat, suggest that Aniselytron should be generically separated from and not merged with Calamagrostis s. l. Due to the adaxial parenchyma in the midrib which has never been found in Pooideae, Aniselytron might have a relationship with some other subfamily.     

The Chromosome Numbers of 10 Species in the Genus Campylotropis (Fabaceae)

This paper reports chromosome numbers of ten species and one variety of the genus Campylotropis from China (Table 1, Plate 1 ). They are C. argentea Schindl., C. bonatiana( pamp: ) Schindl., C. henryi Schindl., C. hirtella (Franch.)Schindl., C. macrocarpa(Bunge )Rehd., C. diversifolia( Hemsl. )Schindl., C. polyantha (Franch.) Schindl., C. polyantha( Franch. )Schindl. var. leiocarpa ( Pamp. ) Pet. -Stib., c. prainii ( Coll. et Hemal. ) Schindl., C. pinetorum (kurz)Schindl. ssp. velutina (Dunn)Schindl., c. trigonoclada(Franch. ) Schindl. The chromosome numbers of these ten species are all 2n= 22 or n= 11, but a few individuals in C. polyantha(Franch. )Schindl. var. leiocarpa(Pamp. )Pet. -Stib., were found aneuploid with 2n=23. The chromosome numbers of c. polyantha and C. macrocarpa have been reported by Maw-shing (1986)andLee(1972), while those of all the other species are first reported.     

Chromosome counts inCephalotus (Cephalotaceae)

Cephalotus follicularis is uniformly n = 10 in all populations surveyed.     

Taxonomic notes on some species of Deyeuxia (Poaceae) from China (II)

Based on both herbarium and field observations, Deyeuxia sikangensis Keng is reduced to the synonymy of D. scabrescens (Griseb.) Munro ex Duthie, and D. levipes Keng to the synonymy of D. nivicola Hook. f. The identity of two names invalidly published, D. dispar L. Liou and D. agrostioides L. Liou, has also been determined, with the former to D. scabrescens, and the latter to D. diffusa Keng, respectively.     

国产香茶菜属十三个分类群的细胞学研究

对国产11种2变种共16个居群的香茶菜属植物的染色体数目进行了研究。除线纹香茶菜细花变种以外,其它种类的染色体数目均为首次报道。研究结果表明,有12个物种为二倍体,其染色体数目均为2n=24,推测该属植物的染色体基数为x=12。而细锥香茶菜既有染色体数目为2n=24的居群,也存在2n=48的居群,表明该种为二倍体或四倍体,同时2n=48的染色体数目也是香茶菜属内的首次报道。     

Calamagrostis hakonensis (Poaceae): Distribution and differentiation of cytotypes

Chromosome counts were made for a total of 540 collections ofCalamagrostis hakonensis from 66 localities ranging from Kyushu to Hokkaido. Distribution and habitat preferences of the cytotypes involved are described. Sympatric occurrence of tetraploids (=semidiploids, 2n=28) and higher polyploids, as well as that of septaploids and plants at hexaploid and/or octoploid levels, was confirmed in several localities, and mixtures of hexaploids and octoploids within a population were frequently observed. Plants at hexaploid and octoploid levels were the most abundant and widespread. An examination of pollen of the voucher specimens showed that tetraploids (amphimictic) had good pollen, while higher polyploids (apomictic) were generally devoid of pollen and very rarely produced moderately good pollen, the grains of higher polyploids being larger than those of tetraploids. Distributions of tetraploids and higher polyploids were more precisely delineated through an examination of pollen of many herbarium specimens. In relation to the processes by which the complicated internal structure ofC. hakonensis has been established, the following subjects are discussed: infraspecific hybridization between ecotypically differentiated populations, enrichment of variability through occasional sexual reproduction expected in plants with more than 2n=42, persistence of the variants by apomictic reproduction, and probable roles of some extinct taxa.