Biosystematic study ofSedum L. SubgenusAizoon (Crassulaceae)

Variation in chromosome number and morphological characters ofSedum aizoon L. var.floribundum Nakai were investigated to analyze, correlations between them. Geographical variation in chromosome number was also examined. Chromosome numbers of 189 individuals from 55 localities were counted as 2n=32, 33, 34, 48, 61, 64, 78, 80, 84, 85, 88, 93, 94, 95, 96, 97 and 102. InSedum subgenusAizoon, which has the basic number of X=8, var.floribundum of the speciesaizoon showed a polyploid series from tetraploid to dodecaploid. Tetraploids were found most frequently in this variety. More than two chromosome numbers were found in all the populations with 2n=61 or more. Tetraploids were mainly distributed in the eastern part of Japan, and higher polyploids (higher than hexaploid level except octaploids) were distributed in the western part of Japan. Thirteen morphological characters were examined in 119 individuals belonging to 30 populations. The principal component analysis and the cluster analysis of these characters indicated that populations with similar chromosome numbers were not always morphologically similar. Ten morphotypes can be recognized based on the combination of chromosome number and morphological characters. ThusS. aizoon var.floribundum can be regarded as a polyploid-aneuploid complex.     

The allopolyploid origin ofSedum rupestre subsp.rupestre (Crassulaceae)

InSedum rupestre L. a polyploid series (x = 16) occurs in which aneuploid chromosome numbers and odd levels of ploidy prevail. The most common and widely distributed cytotype,S. rupestre subsp.rupestre, is 2n = 112. Plants resemblingS. rupestre subsp.rupestre can be obtained by hybridizing the tetraploid cytotypes ofS. forsterianum Sm. (2n = 48) andS. rupestre subsp.erectum 't Hart (2n = 64). Comparison of these artificial hybrids with their parents and a large number of plants ofS. rupestre subsp.rupestre (2n = 112) from nature showed thatS. rupestre subsp.rupestre and the artificial hybrids are morphologically indistinguishable, and intermediate betweenS. forsterianum andS. rupestre subsp.erectum. MorphologicallyS. rupestre subsp.rupestre is closer to subsp.erectum than toS. forsterianum. Chloroplast DNA restriction patterns ofS. rupestre subsp.rupestre, however, resembleS. forsterianum more closely. The combined results of the hybridization experiments, the analysis of the cpDNA restriction patterns, and the morphological variation indicate the allopolyploid origin ofS. rupestre subsp.rupestre. Natural hybrids inSedum (Crassulaceae) 4.     

Evolution ofSedum seriesRupestria (Crassulaceae): Evidence from chloroplast DNA and biosystematic data

Evolutionary relationships within the compariumSedum seriesRupestria (Crassulaceae) were investigated by phylogenetic analyses of restriction site variation of the chloroplast genome and morphological variation. DNAs were digested with 21 restriction enzymes and hybridized withS. album cpDNA probes covering the entire genome. A total of 141 ingroup variable restriction sites was identified. Morphological variation was observed in a total of 66 characters. Both datasets were analysed using parsimony methods and compared with evidence from cytology, artificial hybridization and biogeography to infer evolutionary relationships. The results 1) indicate a relatively high level of nucleotide sequence divergence withinS. ser.Rupestria; 2) indicate three main lines of plastome differentiation, which are in agreement with morphology, basic chromosome numbers, and centres of diversity; 3) do not provide a compelling solution for basal relationships; 4) support an earlier hypothesis on reticulation and provide evidence for a third case of allopolyploidy in the series; 5) suggest that interspecific gene flow inS. ser.Rupestria is funnelled through the presumably allopolyploidS. rupestre subsp.erectum.     

Biosystematic studies on the genusIsoetes in Japan I. Variations of the somatic chromosome numbers

The somatic chromosome number of three Japanese species ofIsoetes, I. asiatica, I. japonica andI. sinensis, was determined in 199 individuals from 49 populations. The chromosome number ofI. asiatica was 2n=22, confirming previous reports. However,I. japonica andI. sinensis displayed a diversity in chromosome number. Six cytotypes, 2n=66, 67, 77, 87, 88 and 89, were found inI. japonica; 2n=67, 87, 88 and 89 are new counts in the genusIsoetes. The plants with 2n=66 were the most frequent (72% of total individuals examined) and were distributed throughout Honshu and Shikoku. The plants with 2n=88 occurred in western Honshu and a limited region in northeastern Honshu where the plants with 2n=77 were also found. In contrast, four cytotypes, 2n=44, 65, 66 and 68, were found inI. sinensis. The chromosome numbers ofI. sinensis were reported here for the first time. The plants with 2n=44 occurred only in Kyushu, while the plants with 2n=66 were found throughout a large area of western Japan.     

Alkaloids of theSedum acre-group (Crassulaceae)

The 16 species of theSedum acre-group were investigated for the presence of alkaloids. They areS. acre ofS. ser.Acria, S. alpestre, S. annuum, S. apoleipon, S. borissovae, S. euxinum, S. grisebachii, S. laconicum, S. multiceps, S. sexangulare, S. tuberiferum, S. tuberosum, S. ursi, andS. urvillei ofS. ser.Alpestria, S. samium ofS. ser.Samia, andS. litoreum ofS. ser.Litorea. S. acre differs significantly from the other species. It contains sedamine, hydroxy sedamine, and a number of 2,6-disubstituted piperidine alkaloids. The leafy parts of the species ofS. ser.Alpestria, S. ser.Samia, andS. ser.Litorea contain 4 piperidine alkaloids which also occur inS. acre, and in addition 4 pyrrolidine alkaloids not present inS. acre. The composition of the alkaloid fraction agrees with the infrageneric classification (series) based on the hybridization patterns of the species (comparia).     

Biosystematic studies inTulipa sect.Eriostemones (Liliaceae)

Evolutionary relationships and infra- and interspecific variability within the species ofTulipa sect.Eriostemones Boissier were studied. Measurements of 35 morphological characters were used for principal component and canonical variate analyses. Crossing experiments and chromosome counts were carried out. Two axes of morphological variation were encountered within the principal component plot. Variation of subsect.Biflores was traced along one axis, the species of subsect.Australes as well asSaxatiles were found along the other axis. The nomenclature of names of subsect.Biflores was considered on the basis of their geography, specific morphological characteristics and polyploidy. Conspecificity of names of all species was tested based on both morphology and crossability.     

Biosystematic studies in European species ofGladiolus (Iridaceae)

Representative specimens of the EuropeanGladiolus species (excl.G. palustris) were used to study variability and relationships. 25 characters were measured for cluster, principal component and Wells hybrid analyses (Figs. 1–3). Three (with PCA) respective five (cluster analysis) main groups are revealed. Bulb characteristics appear to be very useful for indentification. The subspecific status ofG. communis subsp.byzantinus is confirmed. Hybrids of four different parental combinations were detected in our collection. Most species include polyploid series. Partly 3x, 4x, 6x, 8x, 12x and aneuploid cytotypes but no diploids were found. Polyploids as pioneers and hybridization of sympatric species are apparently linked to migrations during the glacial periods.     

Sedum surculosum andS. jaccardianum (Crassulaceae) share a unique 70 bp deletion in the chloroplast DNA trnL (UAA)-trnF (GAA) intergenic spacer

TrnL (UAA)-trnF (GAA) chloroplast DNA spacer sequences of three species ofMonanthes, Sedum surculosum (=Monanthes atlanticum) andS. jaccardianum were compared.S. surculosum, the systematic position of which has been disputed ever since its discovery, shares a phylogenetically highly significant 70 bp deletion withS. jaccardianum. In addition to this large deletion the two Moroccan species ofS. ser.Monanthoidea differ in three more indels as well as in four nucleotide substitutions from the species ofMonanthes. These data render strong support for the monophyly ofS. ser.Monanthoidea andMonanthes. Spacer length in seven species and one subspecies ofMonanthes is relatively uniform.     

Biosystematic study ofRoegneria tenuispica, R. ciliaris andR. pendulina (Poaceae:Triticeae)

Morphological and cytological studies of three tetraploidRoegneria species,R. tenuispica, R. pendulina andR. ciliaris, and their artificial hybrids were carried out.Roegneria tenuispica was morphologically similar toR. pendulina. The general appearance of the interspecific hybrids was intermediate between the parents. The hybrids showed comparatively high chromosome pairing at meiosis, but were completely or almost completely sterile. The results indicate that the three independent species share two basic genomes (S_tY) and thatR. tenuispica is more closely related toR. pendulina than toR. ciliaris. The genomes ofR. tenuispica could be designated as S _t ^t Y^t.     

披碱草属3组植物叶片解剖特征及其系统关系

采用石蜡切片法对披碱草属中小颖组、宽颖组和长颖组主要代表种的叶片横切面形态学特征进行观察。结果显示:(1)披碱草属3个组植物的叶片均为等面叶,由表皮、叶肉和维管束三部分构成,表现为典型的狐茅型,即表皮细胞形状、大小和排列不均,叶肉无栅栏组织和海绵组织之分,具有双层维管束鞘,周围叶肉细胞呈不规则排列,厚壁组织与表皮相接;但3个组植物在上表皮细胞形状、大小、沟的深浅,以及大型导管数目等叶片横切面特征上存在明显差异。(2)根据3个组植物叶片横切面性状的演化趋势,对各组的演化关系和系统位置分析表明,小颖组最原始,宽颖组较进化,长颖组最高级;小颖组可能直接派生了较进化的宽颖组,并在宽颖组的基础上进而产生了最高级的长颖组;小颖组、宽颖组和长颖组的这一系统关系与利用外部形态特征所获得的演化趋势基本一致。     

Plant regeneration from cotyledonary protoplasts of cauliflower (Brassica oleracea L. var.botrytis L.)

Summary Protoplasts isolated enzymatically from precultured cotyledonary leaves ofB. oleracea var.botrytis and cultured in KM8p medium (Kao andMichayluk 1975) underwent sustained divisions in about 0.1% population to eventually produce callus, whereas mesophyll protoplasts from either field grown orin vitro raised plants failed to divide. The callus readily differentiated on Murashige-Skoog medium as modified for shoot culture (Binding 1974) to give rise to shoot and roots.     

Recycling of CO2 via Crassulacean acid metabolism in the rock outcrop succulent Sedum pulchellum Michx. (Crassulaceae)

Under well-watered conditions in the laboratory, Sedum pulchellum assimilated CO₂ only during the day, yet exhibited small nocturnal increases in tissue acid content followed by deacidification in the light (CAM-cycling). When drought-stressed, little CO₂ was fixed in the day and none at night, yet even greater acid fluctuations were observed (CAM-idling). Calculations indicate that water savings associated with CAM-cycling when water is available are small. Water saving is more likely to be significant during CAM-idling when water supply is limited and stomata are closed day and night. Thus, in this species, CAM-idling may be of greater benefit to the plant, relative to CAM-cycling, in surviving habitats prone to frequent drought stress.Abbreviations A CO₂ exchange rate - CAM Crassulacean acid metabolism - c_i shoot internal CO₂ concentration - g_c shoot conductance to CO₂ - PPFD photosynthetic photon flux density - WUE water-use efficiency Supported by National Science Foundation Grant No. DMB 8506093.     

Ornamentation of the testa inSedum (Crassulaceae)

A SEM investigation of the seeds of 40 European and 5 Asiatic species ofSedum revealed three fundamentally different types of ornamentation of the testa. The most prominent difference in the ontogeny of the seeds differing in ornamentation is the ovular envelope, which is a mucous membrane enclosing the ovules and young seeds and occurring only in plants whose seeds have a simple type of ornamentation. The ornamentation of the testa was found to be a very constant character. Because the ornamentation is highly correlated with the hybridization pattern of the species it is considered to be an important character in the infrageneric classification ofSedum.     

Efficient callus induction and plant regeneration from anther of Chinese narcissus (Narcissus tazetta L. var. chinensis Roem)

Callus culture has, to date, been reported only in a few species of Narcissus. We used anthers of Chinese narcissus (Narcissus tazetta L. var. chinensis Roem) as explants for callus induction and plant regeneration. A high percentage of anthers at the early- to mid-uninucleate microspore stage were responsive on the basal MS medium supplemented with 0.5–1 mg l^–1 2,4-dichlorophenoxyacetic acid and 0.5–2 mg l^–1 6-benzyladenine under dark conditions. Calli were initiated from anther connective tissue or anther wall tissue, and no division of microspores occurred during callus formation, as determined by histological observation. Using 20 random amplified polymorphic DNA primers, we verified the genetic integrity of the anther-derived plants of Chinese narcissus with respect to the donor plants. These results suggest that anther culture in vitro can provide an efficient new micropropagation technique for Chinese narcissus as well as a new strategy for in vitro mass propagation of other daffodils.     

Biosystematic investigations on the lady fern(Athyrium filix-femina)

In EuropeAthyrium filix-femina has a constant chromosome number (2n = 80) and is sexual. The normal type of reproduction is intergametophytic crossing. In the gametophyte phase there is a hormone system which induces dark germination of spores and antheridium formation. Sporophytes originating from single prothalli show that a genetic load is present in all population examined. It appears not to be a simple allelic load but a complicated balanced system. Morphological variability can be interpreted as the expression of the genetic heterogeneity of populations. There are no crossing barriers, not even between insular populations hundreds of kilometers apart.     

Hybridization and evolution inCardamine (Brassicaceae) at Urnerboden, Central Switzerland: Biosystematic and molecular evidence

Hybridization between two diploid (2n = 2x = 16) species ofBrassicaceae, Cardamine rivularis andC. amara, at Urnerboden, Central Switzerland, resulted in the rather unusual triploid hybridC. insueta (2n = 3x = 24), and later on in the amphiploidC. schulzii (2n = 6x = 48). The hybrid and the neopolyploid species colonized successfully some man-made biotopes. Plants ofC. insueta are mostly functional females with non-dehiscent anthers, but true hermaphrodite individuals with partly sterile pollen grains also occur within the population. Analyses of cpDNA and nuclear DNA permitted to establish the parentage of the hybrid: the maternal parent which contributed unreduced egg cells proved to beC. rivularis whereas the normally reduced pollen originated fromC. amara. The pronounced genetic variability inC. insueta revealed by isozyme and RAPD analyses, at variance with the polarized segregation, heterogamy and strong vegetative reproduction of the hybrid, is possibly influenced by recurrent formation ofC. insueta which party results from backcrosses betweenC. insueta andC. rivularis but may also proceed by other pathways. The amphiploidCardamine schulzii has normally developed anthers but its pollen is sometimes highly sterile. The surprisingly uniform genetic make-up of the new amphiploid species might be related to its possible monotopic origin and/or young phylogenetic age but should be further assessed. Site management seems to be very important to a further development of hybridogenous populations and their parent species. In conclusion, the evolution at Urnerboden is discussed in the context of the traditional concept of multiple plant origins.     

Reproduction and development of the endangered Sedum integrifolium ssp. leedyi (Crassulaceae)

Information on reproduction and life history is important for the conservation of endangered plants. We investigated rates of flowering, seed set, and germination in populations of the endangered perennial plant Sedum integrifolium ssp. leedyi. Germination and flowering rates differed significantly among populations, but seed set rate did not. We assayed 26 plant clusters (81 stems) from four of the five known populations for evidence of clonal reproduction using 28 randomly amplified polymorphic DNA (RAPD) markers. Of the 81 stems, 75 had unique genotypes and three pairs had identical genotypes, suggesting that clonal reproduction is infrequent. Flowering, seed set, and germination rates were correlated with our estimates of ratios of effective to actual population sizes (Ne/N), but not with Ne. The single formally protected population may be experiencing inbreeding depression. We grew plants from seed to maturity in a greenhouse, with a germination rate of 77% and survival of 98% of the germinants at 6 mo, suggesting that this will be a viable means of ex situ propagation. Plants flowered 4-6 mo after germination and produced mature fruits 1-2 mo later, suggesting that they have the potential to sexually reproduce in their first or second season of growth.     

Electrophoretic variation in esterases and peroxidases of native greek diploidAegilops species(Ae. caudata andAe. comosa,Poaceae)

The esterase and peroxidase patterns in five varieties ofAegilops caudata (genome type C) andAe. comosa (genome type M) were studied in order to elucidate the phylogenetic relationships within and between the two groups. The electrostarch gel electrophoresis technique was applied to extracts of shoot and root of 4-day-old seedlings, and the electropherograms were evaluated by gel densitometer traces. Inspite of considerable isozyme polymorphism, closer relationships in the banding patterns were found between different varieties of a single species than between varieties of the two different species. Esterase and peroxidase patterns of the twoAe. caudata varieties (caudata andpolyathera) are very similar and prove their close phylogenetic relationship. The isozyme affinities withinAe. comosa varieties are illustrated by the seriessubventricosa—biaristata—thessalica. The latter endemic variety has quite a number of characteristic bands and is relatively isolated. Altogether, the electrophoretic data agree well with morphological and cytological similarities (Zhukovsky 1928,Eig 1929,Karataglis 1973, 1975b).     

广西景天科景天属植物小志

该文基于文献考证、馆藏标本鉴定及野外调查，对广西景天属(Sedum L.)植物进行了系统的梳理，对景天属植物物种多样性进行概述，确定目前分布有17种，其中有6个新记录种。该文概述了广西景天属植物物种多样性，订正了藓状景天(S.polytrichoides Hemsl.),简述了6个新记录种，即钝萼景天(S.leblancae Hamet.)、黎平景天(S.lipingense R. B. Zhang, D. Tan&R. X. Wei)、龙泉景天(S.lungtsuanense S. H. Fu)、圆叶景天(S.makinoi Maxim.)、细小景天(S.subtile Miq.)、土佐景天(S.tosaense Makino),并提供其形态特征集要与彩色照片。该文还对广西景天属植物的多样性以及资源潜在利用价值等进行了讨论，并附有分种检索表和各个分类群在广西的分布情况，为该属后续的研究与利用提供了本底资料。