款冬属的核形态（菊科：千里光族）

了款冬属的核形态。染色体间期为简单型与复杂型的过渡型;前期染色体为近基型的过渡型。染色体较小,核型不对称,具明显的二型性;数目与核型公式为２ｎ＝６０＝４２ｍ＋１０ｓｍ＿６ｓｔ＋２ｔ。比较发现款冬的核型不同于千里光族中已有的核型记载,其核型特征似乎与它独特的形态特征相联系,具有重要的系统学意义。     

款冬属的核形态(菊科:千里光族)

研究了款冬属的核形态。染色体间期为简单型与复杂型的过渡型;前期染色体为近基型与中间型的过渡型。染色体较小,核型不对称,具明显的二型性;数目与核型公式为2n=60=42m+10sm+6st+2t。比较发现款冬的核型明显不同于千里光族中已有的核型记载,其核型特征似乎与它独特的形态特征相联系,具有重要的系统学意义。     

菊科千里光簇未冬亚族的花粉超薄结构及其系统学意义

研究了国产菊科千里光族款冬亚族及其相关类群１１属１５种植物的花粉超薄结构。研究类群的花粉超薄结构可分为２类：“千里光型”和“向日葵型”。多榔菊属、大吴风草属和毛冠菊属为“向日葵型”,其余种类均为“千里光型”。根据花粉超薄结构类型,结合其它有关方面的研究,认为大吴风草属与橐吾属并不近缘,而毛冠菊属可能接近于紫菀族。     

新疆千里光族花粉形态研究

在光学显微镜和扫描电镜下,对分布于新疆的菊科千里光族４属２６种植物的花粉进行了观察。根据萌发沟长短和外壁纹饰待征将各属分成二种类型：（１）具长萌发沟：有橐吾属、千里光属和多榔菊属。（２）具短萌发沟：仅有款冬属。由此可看出,款冬是较独立的一类,与其余各属在亲缘关系上相距较远。花粉形态特征为多榔菊属分类地位的探讨提供了资料。同时也为橐吾属两新种的成立提供了孢粉学证据。     

假橐吾属(菊科：千里光族)的核形态研究

首次发表假橐吾属Ligulariopsis Y．L．Chen的核形态研究结果。染色体间期为复杂型,前期染色体为中间型。染色体长度从2．70μm到4．70μm,平均长度为3．62μm,无明显的二型性;核型公式为2n=58=34m+18am(2sat)+6st,核型类型属于2A 。假橐吾属的核型和蟹甲草属与橐吾属相似,但假橐吾属具有较多的亚中部、中部着丝点染色体。     

大吴风草属、假橐吾属花粉表面纹饰及其分类学意义

观察了千里光族款冬亚族中大吴风草属,假橐吾属及其相关类群5属共8种植物在扫描电镜下的花粉性状,所有种类的花粉外壁均为刺状纹饰,但在刺的长短,刺部是否膨大、刺基膨大上的纹饰以及刺基之间的纹饰等方面存在差别,大吴风草的花粉外壁性状不同于橐吾属,从而不支持它与后者有较近亲缘关系的观点它与花粉超薄结构同为“向日葵型”的多榔菊属的花粉外壁性状也不相同,假橐吾属不同于橐吾属和垂头菊属的花粉外壁性状,研究结果支持本单种属的成立。     

菊科千里光族款冬亚族的花粉超薄结构及其系统学意义

研究了国产菊科千里光族款冬亚族及其相关类群 1 1属 1 5种植物的花粉超薄结构。研究类群的花粉超薄结构可分为 2类 :“千里光型”和“向日葵型”。多榔菊属、大吴风草属和毛冠菊属为“向日葵型”,其余种类均为“千里光型”。根据花粉超薄结构类型 ,结合其它有关方面的研究 ,认为大吴风草属与橐吾属并不近缘 ,而毛冠菊属可能接近于紫菀族。     

两种大吴风草的耐荫特性研究

本文通过田间试验和叶绿素分析对上海地区两个品种大吴风草的耐荫性进行初步研究,结果表明大吴风草是喜半荫,耐荫的植物。大吴风草在遮光率达86.4%环境中生长良好,因此在完全郁闭度的树林或灌木丛下作地被具有良好的景观效果。     

稻城千里光(菊科-千里光族)的名实订正

通过标本(包括模式标本)检查,发现稻城千里光(Senecio daochengensis Y. L. Chen)与黑褐千里光(S. atrofuscus Grierson)属于同一种植物,故将前者处理为后者的异名。提供了黑褐千里光的地理分布图及其与近缘种的检索表。     

东亚千里光族款冬亚族的花部微观性状及其系统与分类学意义

所研究的东亚款冬亚族及其相关类群的花部微观性状主要包括：花药顶端不育组织、花药药室内壁、花药基部、花药领、花柱分枝顶端、花柱毛被、花柱分枝内表面构型和果柄细胞列数等。此外,根据所获证据,讲座了款冬亚族花部微观性状的演化趋势。花部微观性状研究表明,毛冠菊属似乎应作为紫菀族中的一个孤立属、狗舌草亚族与千里光亚族和款冬亚族相比,似乎是一过渡类群;东亚款冬亚族１３个属似可划分为６个自然属群。     

Karyomorphology of Ligulariopsis Y. L. Chen (Asteraceae: Senecioneae)

Investigated in the present work was the karyomorphology of Ligulariopsis Y. L. Chen. The interphase nuclei were categorized to be the complex chromocenter type, and the mitotic prophase chromosomes were categorized to be the interstitial type. The metaphase chromosomes ranged from 2.70 μm to 4.70μm with the average 3.62 μm in length. The karyotype was formulated as 2n = 58 = 34m + 18sm(2sat) + 6st and belonged to 2A type. The karyomorphological characteristics of Ligulariopsis are very similar to those of Ligularia and Parasenecio, but there are moresubmedian-centromeric and median-centromeric chromosomes in Ligulariopsis.     

Analysis on Pollen Flow in a Hybridizing Population between Farfugium hiberniflorum and F. japonicum (Asteraceae: Senecioneae): Derivation of an Empirical Formula Describing Frequency of Hybridization as a Function of Interspecific Plant Distance

Abstract The frequency of hybrids was monitored using progenies grown from seeds collected from open-pollinated plants in mixed populations of Farfugium hiberniflorium and F. japonicum . The results showed that hybrids are more frequently derived from F. japonicum than from F. hiberniflorum . This directionality of hybridization and extraordinarily high frequency of hybrids among progenies grown from seeds from open-pollinated plants of F. japonicum enabled us to derive an empirical equation describing the frequency of hybridization as a decreasing exponential function of interspecific plant distance. The relationship between these two variables fitted a function describing pollen flow from a particular plant. This finding suggests that interspecific pollen exchange can be viewed simply as a process dependent of interspecific plant distance, and the actual rate of hybridization is determined by the level of cross-compatibility of a particular species.     

华蟹甲草属和蟹甲草属4种植物的核型

４种植物的染色体间期均为复杂型,前期染色体为中间型。华蟹甲草两居群的染色体数目及核型为２ｎ＝６０＝４４ｍ＋１６ｓｍ（４ＳＡＴ）和２ｎ＝６０＝４２ｍ＋１８ｓｍ（２ＳＡＴ）。蟹甲草属３种：阔柄蟹甲草为２ｎ＝６０＝５０ｍ＋１０ｓｍ;蛛毛蟹甲草为２ｎ＝６０＝５０ｍ＋１０ｓｍ（２ＳＡＴ）;三角叶蟹甲草两居群分别为２ｎ＝６０＝４４ｍ＋１６ｓｍ（２ＳＡＴ）和２ｎ＝６０＝４４ｍ＋１６ｓｍ。核型均为２Ａ型,尽管华蟹     

Karyomorphology of Turkish species in Centaurea sections Centaurea and Phalolepis (Asteraceae) and implications for taxonomy

In this paper, 31 mostly endemic and locally distributed Turkish Centaurea taxa belonging to Centaurea and Phalolepis sections were examined in terms of their karyomorphology. The basic chromosome number for all of the studied species was concurringly determined as 9(x = 9) for both sections, excluding C. hierapolitana. We also determined tetraploid and hexaploid species in spite of many species having diploid chromosome numbers. Twelve chromosome counts are reported for the first time and most of the karyotyping analyses are described for the first time via the KAMERAM program. The karyotypes had a predominance of metacentric (m) chromosomes. However, in the karyotyping of six taxa, submetacentric (sm) chromosomes were dominant. Five quantitative asymmetric indices were used to evaluate karyological features of the species. A meaningful dendrogram was carried out to assess the karyotype-symmetry conditions and describe the karyotyping relationships between different taxa.     

Development of the echinate pollen wall inFarfugium japonicum (Compositae: Senecioneae)

Development of the echinate pollen grains inFarfugium (Compositae: Senecioneae) has been studied by a combination of transmission electron microscopy and field emission scanning electron microscopy with a freeze fractured method. The inner surface of the callose wall surrounding each microspore does not possess an echinate pattern before primexine deposition begins. The primexine formation coincides with the initiation of spines. The freeze fractured primexine shows probacula which form transverse rods. The developing exine has an inner spongy substructure. The endexine is formed by the accumulation of the electron dense lamellae with white lines after the dissolution of the callose wall. In the present study, it is confirmed that the developmental process of pollen formation revealed in the field emission scanning electron microscope is consistent with the results obtained using the transmission electron microscope.     

Development and characterisation of microsatellite loci in Farfugium japonicum (Asteraceae)

Eight microsatellite loci for the perennial herb Farfugium japonicum, including the rheophytic variety luchuense endemic to riparian areas of the Ryukyu Islands, Japan, were isolated and characterised. The number of alleles ranged from 5 to 14. The expected (H _E) and observed (H _O) heterozygosities were 0.344–0.885 and 0.121–0.754, respectively, from 69 individuals in one population. Six loci exhibited significantly fewer heterozygotes than expected under Hardy–Weinberg equilibrium (P < 0.05). The primers amplifying microsatellite sequences in F. japonicum may provide a population genetics tool useful in the establishment of a conservation strategy.     

Leaf morphology of a facultative rheophyte,Farfugium japonicum var.luchuense (Compositae)

The gross morphology and anatomy of leaves in a facultative rheophyte,Farfugium japonicum var.luchuense, were examined in order to clarify how the two characters are correlated with one another and how the facultative rheophyte differs from obligate rheophytes in leaf morphology and anatomy. Most rheophytes of the variety have narrowly cuneate leaf base, while most inland plants usually have truncate to cordate one, although the habitat-morphology correlation is not so clear. The leaf shape or the divergence angle of leaf base is strongly correlated with the number of primary veins and intervein-distance dependent on the number of cells intervening between veins. This makes a marked contrast to many reported cases of obligate rheophytes in which the leaf shape is strongly correlated with cell size. There is a rough tendency that narrower leaves of rheophytes have a thicker cuticular layer. However, the cell size and the volume (area) of intercellular space differ only slightly with the leaf shape.     

Selecting Single-Copy Nuclear Genes for Plant Phylogenetics: A Preliminary Analysis for the Senecioneae (Asteraceae)

Compared to organelle genomes, the nuclear genome comprises a vast reservoir of genes that potentially harbor phylogenetic signal. Despite the valuable data that sequencing projects of model systems offer, relatively few single-copy nuclear genes are being used in systematics. In part this is due to the challenges inherent in generating orthologous sequences, a problem that is ameliorated when the gene family in question has been characterized in related organisms. Here we illustrate the utility of diverse sequence databases within the Asteraceae as a framework for developing single-copy nuclear genes useful for inferring phylogenies in the tribe Senecioneae. We highlight the process of searching for informative genes by using data from Helianthus annuus, Lactuca sativa, Stevia rebaudiana, Zinnia elegans, and Gerbera cultivar. Emerging from this process were several candidate genes; two of these were used for a phylogenetic assessment of the Senecioneae and were compared to other genes previously used in Asteraceae phylogenies. Based on the preliminary sampling used, one of the genes selected during the searching process was more useful than the two previously used in Asteraceae. The search strategy described is valid for any group of plants but its efficiency is dependent on the phylogenetic proximity of the study group to the species represented in sequence databases. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.