华中植物区系新资料

该文报道了产鄂西和湘西北的双子叶植物省级分布新记录1个属和8个种。湖北分布新记录有龙珠(Tubocapsicum anomalum)、直梗高山唐松草(Thalictrum alpinum var. elatum)、虫莲(Sanguisorba filiformis)、腺地榆(S. officinalis var. glandulosa)、平叶酸藤子(Embelia undulata)、广西地海椒(Physaliastrum chamaesarachoides)、东北薄荷(Mentha sachalinensis)、黄鼠狼花(Salvia tricuspis),其中龙珠对应的龙珠属(Tubocapsicum)是湖北新记录属;湖南分布新记录有宝兴藨寄生(Gleadovia mupinense)。根据IUCN标准,宝兴藨寄生属濒危(EN)物种。这些新记录的发现丰富了华中植物区系资料,在植物保护方面也有一定意义。     

POLYMORPHISM IN THE DESMID XANTHIDIUM REGULARE AND ITS TAXONOMIC IMPLICATIONS

This paper refers to a case of polymorphism in the desmid genus Xanthidium Ehr. It is based on material from Lake Dais Irmaios, the main body of water in the Zoological and Botanical Garden in Recife, Pernambuco, northeastern Brazil, collected at 4 different times of the year during 1967 and 1968. A detailed examination of almost 1300 specimens showed an enormous variety in form of Xanthidium regulare Nordst., X. fragile Borge, and X. pseudoregulare Borge, thus allowing the authors to draw the following conclusions: (1) the name X. regulare Nordst. should be retained until further and more detailed studies on form variation within the species are available; (2) the names X. regulare Nordst. var. asteptum Nordst. in Borge, X. regulare Nordst. var. sexangulare Grönbl., X. regulare Nordst. var. sexangulare Grönbl. f. robustior Grönbl., X. fragile Borge, X. fragile Borge forma, and X. fragile Borge var. depauperatum Borge should be considered synonymous, all referring to a single variety of X. regulare Nordst., var. asteptum Nordst. in Borge emend. C. Bic. & L. M. Carv.; (3) X. pseudoregulare Borge must be treated as a variety of X. regulare Nordst. and must be called X. regulare Nordst. var. pseudoregulare (Barge) C. Bic. & L. M. Carv. Finally, a key is given to the 3 varieties of X. regulare Nordst. proposed in the present paper.     

Chromosomal location of genes for novel glutenin subunits and gliadins in wild emmer wheat (<Emphasis Type="Italic">Triticum turgidum</Emphasis> L. var.<Emphasis Type="Italic"> dicoccoides</Emphasis>)

The glutenin and gliadin proteins of wild emmer wheat, Triticum turgidum L. var. dicoccoides, have potential for improvement of durum wheat (T. turgidum L. var. durum) quality. The objective of this study was to determine the chromosomes controlling the high molecular weight (HMW) glutenin subunits and gliadin proteins present in three T. turgidum var. dicoccoides accessions (Israel-A, PI-481521, and PI-478742), which were used as chromosome donors in Langdon durum- T. turgidum var. dicoccoides (LDN-DIC) chromosome substitution lines. The three T. turgidum var. dicoccoides accessions, their respective LDN-DIC substitution lines, and a number of controls with known HMW glutenin subunits were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), urea/SDS-PAGE, and acid polyacrylamide gel electrophoresis (A-PAGE). The results revealed that all three T. turgidum var. dicoccoides accessions possess Glu-A1 alleles that are the same as or similar to those reported previously. However, each T. turgidum var. dicoccoides accession had a unique Glu-B1 allele. PI-478742 had an unusual 1Bx subunit, which had mobility slightly slower than the 1Ax subunit in 12% SDS-PAGE gels. The subunits controlled by chromosome 1B of PI-481521 were slightly faster in mobility than the subunits of the Glu-B1n allele, and the 1By subunit was identified as band 8. The 1B subunits of Israel-A had similar mobility to subunits 14 and 16. The new Glu-B1 alleles were designated as Glu-B1be in Israel-A, Glu-B1bf in PI-481521, and Glu-B1bg in PI-478742. Results from A-PAGE revealed that PI-481521, PI-478742, and Israel-A had eight, 12, and nine unique gliadin bands, respectively, that were assigned to specific chromosomes. The identified glutenin subunits and gliadin proteins in the LDN-DIC substitution lines provide the basis for evaluating their effects on end-use quality, and they are also useful biochemical markers for identifying specific chromosomes or chromosome segments of T. turgidum var. dicoccoides.Communicated by B. Friebe     

Seven new species of Hieracium sect. Tridentata (Asteraceae) from Götaland,southern Sweden

Six new species of Hieracium sect. Tridentata, viz. H. piranhae, H. xanthochlorum, H. bertilssonii, H. erectiramum, H. rigescoides and H. subpardalinum are described from the Götaland region, southern Sweden and H. gothicum var. blekingense is raised to specific rank as H. blekingense.     

Phytosociological characteristics of perennial atriplex-dominated vegetation of Southeastern Utah

Summary Four plant associations of a salt desert area of southeastern Utah were identified by modified Zurich-Montpellier methodology. In this instance, the species of highest fidelity generally possessed the highest values for cover, frequency and constancy. These species and the respective associations to which their names are applied are (1)Atriplex confertifolia, (2)Atriplex nuttallii varnuttallii, (3)Atriplex nuttallii vargardneri and (4)Atriplex corrugata. These phytosociological subdivisions have been used in subsequent hydrological investigztions.

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Zusammenfassung Vier Pflanzengesellschaften eines Salzsteppen-gebietes in Südost-Utah wurden mit Hilfe einer modifizierten Zürich-Montpellier-Methode ermittelt. In diesem Falle besasz im allgemeinen die Art mit der h?chsten Gesellschaftstreue auch die h?chsten Werte für die Decke, die Dichte, und die Best?ndigkeit. Diese Arten und die nach ihnen benannten Gesellschaften sind. (1)Atriplex confertifolia, (2)A. nuttallii varnuttallii, (3)A. nuttallii vargardneri und (4)A. corrugata. Diese pflanzensoziologischen Unterteilungen wurden in anschlieszenden hydrologischen Untersuchunten benutzt.

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Approved by the Director of the Utah Agricultural Experiment Station as Journal Paper No. 1094. Financial support of the Bureau of Reclamation and Bureau of Land Management, U.S. Department of Interior, is gratefully acknowledged.     

秦巴山区三种人参属药用植物叶绿体基因组特征分析

为明确珠子参、羽叶三七和秀丽假人参3种药用植物叶绿体基因组特征与系统发育关系,该文以秦巴山区3种人参属药用植物为研究对象,运用生物信息学技术,分析其叶绿体基因组特征及密码子使用偏好性,并探讨三者之间的亲缘关系。结果表明:(1)3种人参属药用植物的叶绿体基因组为典型的四分体结构,序列全长为 156 071～156 104 bp,总 GC 含量为 38.10%,基因组大小相似度较高。(2)均注释到 133 个基因,包括 88 个蛋白编码基因、37 个tRNA基因和 8 个 rRNA 基因。(3)3种人参属药用植物叶绿体密码子使用偏好性相似,密码子第 3 位碱基以 A/U 结尾为主,密码子使用模式在受到突变影响的同时,主要受到自然选择的影响。(4)系统发育结果显示,3种人参属药用植物的亲缘关系较近,并且秀丽假人参同羽叶三七亲缘关系更近。综上认为,秀丽假人参与珠子参基源植物之间存在近缘关系,这项发现对于珠子参中药材的资源开发利用和分子鉴定,以及进一步研究人参属物种的分类、系统发育和进化机制提供了重要依据。     

Microbiota in Wheat Roots Evaluated by Cloning of ITS1/2 rDNA and Sequencing

Fungi (17 species), oomycetous organisms (four species of Pythium) and a plasmodiophorid (Polymyxa graminis) were recorded in wheat roots analysed by cloning of the total ITS1/2 rDNA and sequencing of representative clones. Roots of a fourth successive wheat crop were inhabited mostly by fungal pathogens including Gaeumannomyces graminis var. tritici, Monographella nivalis var. nivalis, Ophiosphaerella sp. and Helgardia anguioides. Roots of a first wheat crop were inhabited mostly by P. graminis and saprotrophic Pythium species. Results on fungal diversity and density were compared with those obtained by pure culture isolation and morphotyping. Only M. nivalis var. nivalis and H. anguioides were identifed in wheat roots by both the molecular and the pure culture isolation methods. New and additional evidence for the ecological roles of the species recorded is discussed.     

NUTRITIONAL REQUIREMENTS OF HAEMATOCOCCUS PLUVZALIS AND RELATED SPECIES1

All the described species and varieties of the genus Haematococcus were available. After isolation in pure culture they were used studying their nutritional requirements. H. buetschlii and H. droebakensis had already been shown by Droop to need vitamin B₁₂. H. capensis typ., H. capensis var. borealis, and H. zimbabwiensis were found to do so also. The 7 strains of H. pluvi-alis from various localities investigated showed slight physiological deviations, although morphologically they were so similar that they should not be described as varieties. A dilute inorganic nutrient solution with trace elements and iron kept in solution by EDTA was suitable either as such or supplemented with growth-promoting compounds. The growth was speeded by low concentrations of acetate and by enhancing photosynthesis. No strain of H. pluvialis absolutely required cobalamin, although it stimulated. Thiamine had a much more pronounced effect; for some strains it was indispensable. Although the response varies slightly from strain to strain, a luxuriant growth for all was obtained only with acetate and B₁, and usually enhanced by B₁₂. A peculiar feature of H. pluvialis is the catching up of cultures initially retarded by thiamine deficiency (probably due to slow B_l synthesis). When H. pluvialis multiplied fast its appearance differed from that considered typical: no red pigment and the cell wall not inflated. In nature it evidently lives under conditions unfavorable for good growth although suitable for survival in competition with other organisms.     

VALVE AND BAND MORPHOLOGY OF SOME FRESHWATER DIATOMS I. FRAGILARIA CAPUCINA VAR. MESOLEPTA1,2

Acid cleaned cells from clonal cultures of Fragilaria capucina var. mesolepta Rabh. were examined with light and scanning electron microscopy. Recently isolated cells are linear-lanceolate in shape with a median constriction. After several transfers over 25 mo, cells exhibit size diminution resulting in small elliptically shaped valves. Adjacent valves are united to one another by interlocking marginal spines. Every valve has an apical pore field at each apex. A single labiate process is present infrequtently, appearing underdeveloped most often in size-reduced cells. The girdle region consists of two cingula, each composed of a series of underlapping bands. Each pleura in the series is a discontinuous ring with a central ligula. A survey of past ultrastructure studies on the freshwater Fragilariaceae reveals that the occurrence of the apical pore field and labiate process are likely key characteristics for the family. The apical pore field of Diatoma, Asterionella and Tabellaria is positioned on the valve face, whereas the apical pore field of F. capucina var. mesolepta is located on the valve mantle, the girdle region of F. capucina var. mesolepta is basically similar to that of Gomphonema parvulum (Kütz.) Grun.     

基于低拷贝核基因GBBSI的禺毛茛复合体系统进化研究

禺毛茛多倍体复合体及其近缘种系统进化关系复杂,杂交与多倍化现象同时存在。该复合体内高倍性植物的形成及扩散过程仍需进一步研究。首次克隆了毛茛属植物低拷贝核基因颗粒结合型淀粉合成酶 I (GBBSI )基因,并利用其构建禺毛茛多倍体复合体及其近缘种的系统进化树和网状进化关系,进而证明其适合于研究毛茛属植物种下系统发育研究。结果表明：匍枝毛茛与多倍体复合体关系密切,参与了该多倍体复合体的起源和进化;禺毛茛起源于茴茴蒜和卷喙毛茛,扬子毛茛起源于茴茴蒜和匍枝毛茛;在该类群中茴茴蒜是个关键种,它在多倍体复合体中可能起着枢纽基因组的重要作用。     

南方红豆杉水浸提液对喜树种子发芽和幼苗生长的化感作用

化感作用是影响人工混交林种间关系的重要因素之一。已有研究表明：喜树南方红豆杉混交对喜树生长有明显促进作用,并从混交改善混交林地微气候角度解释了这种促进作用,但未从种间化感作用角度探讨这种作用。为了探究南方红豆杉是否对喜树具有潜在的化感促进作用,从而更全面了解喜树南方红豆杉混交林种间关系,考察了不同浓度（25、50 g/L和100 g/L）的南方红豆杉（Taxus chinensis var.mairei）鲜叶、凋落叶、枝和根水浸提液对喜树（Camptotheca acuminata）种子发芽和幼苗生长的影响。结果表明：（1）南方红豆杉凋落叶浸提液对喜树种子发芽和幼苗生长无显著影响（P>0.05）,而鲜叶、枝和根浸提液对喜树发芽和幼苗生长均具有不同程度的促进作用（P<0.05）,且作用强度大体与浓度呈正相关;（2）100 g/L的南方红豆杉鲜叶、枝和根浸提液浸泡的喜树种子,其发芽率比对照组分别提高8.1%、14.9%和25.6%;（3）南方红豆杉鲜叶浸提液只有在高浓度（100 g/L）时,对喜树幼苗基径生长具有促进作用（P<0.05）,而对其株高、全株干重和净光合速率无显著影响;南方红豆杉根和枝浸提液对喜树幼苗株高、基茎、干重和净光合速率均具有促进作用（P<0.05）,与对照组相比,100 g/L的根和枝浸提液浇灌喜树幼苗,可以使喜树幼苗株高分别提高14.2%和8.4%,基径分别提高19.0%和15.3%,干重分别提高23.1%和15.9%,净光合速率分别提高11.6%和6.1%。研究结果表明,在喜树南方红豆杉混交林中,南方红豆杉对喜树的正向化感作用可能是促进喜树生长的重要因素之一。     

Karyotypes,heterochromatin distribution and rDNA patterns in South American Grindelia (Asteraceae)

Grindelia is a genus with a complex evolutionary history with reticulate evolution. We studied the karyotype, fluorescent banding, and fluorescence in situ hybridization (FISH) using 18–5.8–26 S and 5 S ribosomal DNA probes to survey karyotypic diversity of South American Grindelia species. Chromosome basic numbers were x = 6 (with several ploidy levels: 2x, 4x, and 6x). All the Grindelia studied conserved the patterns of CG-rich heterochromatin and 18-5.8-26 S rDNA. The third m sat-chromosome pair was homeologous in Grindelia. Chromosome variation, although not always large, accompanied the evolutionary divergence of the taxa studied. The Grindelia studied formed two species groups: (1) G. globularifolia and G. pulchella var. pulchella, (2) G. buphthalmoides, G. cabrerae var. alatocarpa and var. cabrerae, G. chiloensis, G. orientalis, and G. prostrata. These groups do not show any morphological affinities and their phylogenetic relationships are not clearly resolved, suggesting that these groups have recently diverged.     

Evaluation of Brassica germplasm for field resistance against clubroot (Plasmodiophora brassicae Woron)

Of the 124 germplasm accession of oil seed Brassicas screened under field condition against clubroot disease (Plasmodiophora brassicae), 80% were susceptible and 17, 3, 1 and 1 of Brassica juncea, Brassica rapa var. toria, B.rapa var. yellow sarson and B. rapa, respectively, were resistant.     

Where do Sardinian orchids come from: a putative African origin for the insular population of Platanthera bifolia var. kuenkelei?

Because of the complex geoclimatic dynamics of the Mediterranean basin, resulting from a combination of Tertiary geological processes and Quaternary climatic oscillations, the current species composition of the main continental islands is a mosaic resulting from relative contribution of vicariance, geodispersal and long‐distance dispersal by seed. To help distinguish among the contributions of these different dispersal modes to the orchid species richness on the island of Sardinia, we investigated the genetic structure and phylogeographic relationship of the only Platanthera bifolia var. kuenkelei population on the island. By using plastid DNA sequence variation, we show that this recently discovered population is more closely related to the Tunisian P. bifolia var. kuenkelei than to the geographically closer P. bifolia populations from peninsular Italy. Results from haplotype network construction support the hypothesis that the current distribution of P. bifolia var. kuenkelei (Sardinia and Tunisia) is most likely explained by over‐sea dispersal. However, haplotype diversity and mismatch analysis of this unique Sardinian population suggest that, if a long‐distance dispersal event did occur, it was not recent. More likely, temporarily favourable climatic conditions generated a suitable habitat on the island (also in terms of suitable mycorrhizas and pollinators) and thus a transient opportunity for seedling growth and population establishment of P. bifolia var. kuenkelei from North Africa. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 167 , 466–475.     

Genomic constitution and taxonomy of the Chinese hexaploids Elymus cylindricus and E. breviaristatus (Poaceae: Triticeae)

Elymus cylindricus (2n = 6x = 42) and E. breviaristatus (2n = 6x = 42) are distributed in grasslands and deserts of northern and north‐western China. Their genomic constitution and taxonomic status are unclear. Elymus cylindricus was crossed with E. wawawaiensis J.R.Carlson & Barkworth ( StH ), Roegneria grandis Keng ( StY ) and Campeiostachys dahurica (Turcz. ex Griseb.) B.R.Baum, J.L. Y ang & C. Y en var. dahurica ( StYH ). Meiotic pairing in the hybrids E. cylindricus × E. wawawaiensis ( StH ), E. cylindricus × R. grandis ( StY ) and E. cylindricus × C. dahurica var. dahurica ( StYH ) showed on average 10.00, 11.30 and 20.92 bivalents per cell, respectively. Elymus breviaristatus was crossed with C. dahurica var. dahurica ( StYH ) and E. cylindricus. Chromosome pairing in the hybrids of E. breviaristatus × C. dahurica var. dahurica and E. breviaristatus × E. cylindricus showed on average 19.60 and 19.27 bivalents, respectively. Genomic in situ hybridization (GI SH ) revealed the presence of St , Y and H genomes in E. cylindricus and E. breviaristatus. An intergenomic rearrangement was observed in E. cylindricus using GI SH . Meiotic pairing data and GI SH indicated that both E. cylindricus and E. breviaristatus are allohexaploids containing the StYH genomes. Elymus cylindricus and E. breviaristatus should be treated as Campeiostachys dahurica var. cylindrica and Campeiostachys breviaristata, respectively.