云南竹亚科梨藤竹属的修订

梨藤作为中国新分布种发表时所引证的标本为另外的竹种,经研究本种在中国无分布,而原发表的新种流苏梨藤竹（M．fimbriatus）为其变种,本文将其作为1个新等级,并对其花部特征进行了补充描述,从而确定云南分布梨藤竹属竹子有2种,1变种,并编制了分种检索表。     

云南竹亚科一些属种的增订

报道了云南竹亚科新名称１个,新组合１个,新异名１个,发现１个不合格名称,１个属在云南分布的新记录和１个种在我国分布的新记录。同时讨论了单枝竹属和空竹属的地理分布。     

Phylogenetic studies of a large data set. I. Bambusoideae,An-dropogonodae,and Pooideae (Gramineae)

The online version of the original article can be found at     

Chromosome relationships between Lolium and Festuca (Gramineae)

With a view to eclucidating chromosome relationships between Lolium perenne (Lp), L. multiflorum (Lm) and Festuca pratensis (Fp), chromosome pairing in different diploid (2n=14), auto-allotriploid (2n=3x=21), trispecific (2n=3x=21), amphidiploid (2n=4x=28) and auto-allohexaploid (2n=6x=42) hybrids between them was analysed. At all these levels of ploidy there was very good chiasmate pairing between the chromosomes of the three species and, on the whole, there was little evidence of preferential pairing of the chromosomes of a particular species in the triploid, tetraploid and hexaploid hybrids. A critical test for this also came from the synaptic ability of the chromosomes of the single genome with those of the duplicated genome in the auto-allotriploids which formed predominantly trivalents with 2, 3 or even 4 chiasmata. Moreover, the homology between the Lp and Lm chromosomes seems strong enough to pass the discrimination limits of the B-chromosomes which do not suppress homoeologous pairing in the Lp LmLm triploid and LpLm diploid hybrids. — The triploids having two genomes of a Lolium species and one of F. pratensis had some male and female fertility which suggested genetic compatibility of the parental chromosomes resulting, presumably, in compensation at the gametic level. Also, the occurrence of comparable chiasma frequencies in the auto-allotriploids and trispecific hybrids showed that they were not markedly affected whether two doses of one genome and one of the other or all the three different genomes from the three species were present. From the trend of chromosome pairing in all these hybrids it is concluded that there is little structural differentiation between the chromosomes of the three species, no effective isolation barrier to gene-flow between them, and that they are closely related phylogenetically, having possibly evolved from a common progenitor. Taxonomic revision of the two Lolium species is suggested.     

Phytogeographical studies ofCalamagrostis sachalinensis (Gramineae)

Chromosome numbers were determined on 223 collections ofCalamagrostis sachalinensis from 18 localities in Japan. The plants were found to be tetraploid (2n=28), hexaploid (2n=42) or octoploid (2n=56). A few collections were found to include one or two B-chromosomes. The tetraploid collections were made from central Honshu and Mt. Apoi in Hokkaido, while the hexaploids and the octoploids were detected in many localities. Pollen examination of these collections showed that the tetraploids with but one exception have good pollen and the hexaploids and the octoploids have no pollen or have bad pollen with stainability less than 10%. With the help of pollen examination of a number of herbarium specimens, the distribution of the tetraploids and that of the assemblage of the hexaploids and octoploids were delineated. Morphological studies indicated that the tetraploid, hexaploid and octoploid plants can not be separated in gross and spikelet morphology and that the tetraploids in central Honshu and those in Mt. Apoi are significantly different in leaf features. It was concluded thatC. sachalinensis represents an apo-amphimictic complex, which includes the following four races: 1) tetraploid, amphimictic, having thin leaf blades 5–10 mm broad and growing on the subalpine conifer forest belt and the conifer forest-alpine ecotone in the mountains of central Honshu; 2) tetraploid, amphimictic, having hard leaf blades 2–6 mm broad and growing on the stony, arid and exposed alpine belt on Mt. Apoi in Hokkaido; 3) hexaploid, mainly apomictic, the most variable ecologically, widely distributed; 4) octoploid, mainly apomictic, frequent in the upper montane to alpine belts, probably widely distributed.     

安徽刚竹属新植物

描述了产于安徽境内的竹亚科刚竹属4个新种,即:糙竹、燥壳竹、广德芽竹、谷雨竹,并讨论了与近缘类群的区别,提供了显示鉴别特征的活植物及模式标本图片.新种的主模式标本均保存于安徽农业大学树木标本馆.     

西藏特有竹子Arundinaria macclureana的名实辨正

Arundinaria macclureana是在现代植物学中根据在西藏采集的标本描述的第一个竹子。其模式标本是1938年采集的,但只有花枝,没有地下茎、秆箨等重要特征。尽管如此,该种还成为了新属Borinda的模式种。在研究了其模式标本后,使本文第一作者联想起1991年在藏东南采集的西藏箭竹（Fargesia setosa）。西藏箭竹的模式标本采集于1977年,但只有营养体,没有花枝。在对比研究两个名称的模式后,确认二者实为同种。经与共同作者一起讨论,认为其正确学名为Fargesia macclureana,但该种所在的筱竹属群的关系还有待进一步的研究。     

Experimental studies of evolution inAnthoxanthum (Gramineae)

Hybridization reveals the close affinity ofAnthoxanthum odoratum and the Mediterranean annualA. ovatum. A. alpinum is genetically somewhat more isolated; occasional sterile hybrids withA. ovatum can be obtained.Morphology reveals an affinity betweenA. odoratum andA. ovatum. There are nodiagnostic characters linkingA. odoratum toA. alpinum.The perennial nature of the generality ofA. odoratum, plus phenotypic flexibility and an ability to behave as an annual in particular habitats, suggest an affinity both toA. alpinum (winter-hardy perennial) andA. ovatum (variable annual or occasional biennial).The artificial allotetraploid based on the sterile hybrid betweenA. alpinum andA. ovatum simulatesA. odoratum, more closely than do either of the diploids.Experimental observations suggest a very reasonable possibility that a similar sequence of events perhaps occurring on several occasions under natural conditions could have given rise to the tetraploid speciesA. odoratum.     

云南德宏傣族景颇族自治州竹亚科(禾本科)植物区系地理研究

云南南部和西南部是中国竹类资源最为丰富的地区 ,与其邻近地区一起构成了世界木本竹类的多样性中心。德宏正处于这个中心位置 ,竹子种类丰富 ,有 16属 5 6种及变种 ,其中中国特有种 2 1种 (云南特有 15种 ) ,占其竹亚科全部区系成分 (45种 )的 4 6 6 7%。热带亚洲分布类型占绝对优势 ,本地区的竹亚科区系与热带亚洲特别是缅甸 (有 18种共有种 )及云南南部和东南部有非常密切的联系     

Schizostachyum yalyense sp. nov. and S. ninhthuanense sp. nov. (Gramineae: Bambusoideae) from Vietnam

Two new species of Schizostachyum Nees (Poaceae: Bambusoideae): S. yalyense N. H. Xia, V. T. Tran et H. N. Nguyen and Schizostachyum ninhthuanense N. H. Xia, V. T. Tran et H. N. Nguyen (Poaceae: Bambusoideae) are described and illustrated from Vietnam. Schizostachyum yalyense is similar to S. lima (Blanco) Merrill, but differs by culm sheaths with a concave apex 4–5 cm wide and 1.0–1.5 cm deep, pseudospikelets clustered on the wholly leafless flowering branches, possession of 2 bracts and lodicules. Schizostachyum ninhthuanense is related to S. hainanense Merrill ex McClure, but differs by culm sheaths covered with white hairs and having white–brown hairs at the apex, ligule margin densely pale‐ciliate, pseudospikelets clustered on wholly leafless flowering branches, presence of 3 lodicules, two stigmas apically on the style and the third stigma branching off from one of the two other stigmas.     

Nucellar degeneration inCortaderia (Gramineae)

Summary Vigorous degradation of nucellar tissue in the apomictic grassCortaderia jubata is associated with early degeneration of the megaspore mother cell and the subsequent enlargement of several cells to form somatic embryo sacs. Nucellar degeneration is recognised by the separation of the nuclear membranes, at first along only small sectors of the nucleus, and the appearance within the enlarging perinuclear space of vesicles formed by blebbing of both the inner and outer membranes of the nuclear envelope. Invaginations of the bounding membrane of the dilating RER are responsible for many single-membrane-bound vesicles lying in cisternae throughout the cytoplasm. Eventually the nucleus, enclosed mainly in the inner nuclear membrane, and the cytoplasm, are subject to extensive vesicularization. An electron opaque substance is present in the perinuclear space, in the ER, in vacuoles, and outside the plasmalemma adjacent to the degenerating cell wall, and is similar to a substance which appears on the inner and outer membrane surfaces of mitochondria during later stages of cell degeneration. It is suggested that the genesis and growth of embryo sacs inC. jubata are linked with a programmed nucellar cell autolysis.     

DNA values in the genus Phalaris (Gramineae)

In the genus Phalaris diploid species with 2n=12 have approximately twice the DNA content per cell found in species with 2n=14; i. e. the first group has chromosomes about twice the size of the other group. DNA content per unit length suggests that the difference is reflected more in the diameter of the metaphase chromosome than in the lengths. The trend in evolution seems to be towards increase in DNA content.     

甘蔗亚族的地理分布

对甘蔗亚族植物在世界的分布状况和在中国的分布特点进行了讨论,通过分析甘蔗亚族各属种的分布区类型,认为亚洲东南部为甘蔗亚族的分布中心和多样性中心,同时对甘蔗亚族起源作了推测。     

Apomixis in Eremopogon foveolatus (Gramineae)

The investigation deals with the reproductive behaviour in Eremopogon foveolatus (Del.) Stapf, a member of the tribe Andropogoneae. The magaspore mother cell or the products of its meiotic division degenerate in a majority of ovules and four–nucleate unreduced embryo sacs are formed from the surrounding cells of the nucellus. Eight–nucleate reduced embryo sacs are also formed in some ovules but the percentage of such ovules is very low. The unreduced egg develops parthenogenetically but fertilization of the polar nucleus appears to be essential for the formation of endosperm.     

The cytology of the genus Alopecurus (Gramineae)

For a study of hybridization in Alopecurus , chromosome numbers, karyotypes, meiotic chromosome behaviour and breeding systems have been investigated in six species. In addition to confirming many previous chromosome numbers, new triploid and tetraploid counts have been found in A. bulbosus , which have not previously been reported. The karyotypes of all species have a very similar morphology but there are differences in chromosome size which can be related to differences in nuclear DNA content. At meiosis the diploid species form bivalents, but one population of A. aequalis contains plants that regularly form a single quadrivalent which would appear to be interchange heterozygotes. The meiotic behaviour of the tetraploids suggests that A. pratensis is an allotetraploid and A. geniculatus an autotetraploid. All species appear to be allogamous, although some, such as A. myosuroides are obligate outbreeders resulting from the presence of a self-incompatibility system, outbreeding is promoted in others by differences in the time of maturity of stigmas and anthers.