Paratingia wudensis sp. nov., a whole noeggerathialean plant preserved in an earliest Permian air fall tuff in Inner Mongolia, China

Noeggerathiales are a little known group of Carboniferous and Permian plants of uncertain systematic position that have been variously considered to be ferns, sphenopsids, progymnosperms, or a separate group. These heterosporous plants carry adaxial sporangia on leaf-like or disk-shaped sporophylls that form cones. Leaves are pinnate with a rather stiff appearance, and pinnules can be attached in either two or four rows. In the present report, we present the top of a noeggerathialean plant with leaves and strobili attached, Paratingia wudensis Wang, Pfefferkorn et Bek sp. nov., from an earliest Permian volcanic ash fall tuff in Inner Mongolia. The excellent preservation allows the reconstruction of the whole plant, the complex three-dimensional leaves with anisophyllous pinnules, the heterosporous strobili, and the spores in situ. The homology of leaves and strobili can be elucidated and contributes to an understanding of the debated taxonomic position of Noeggerathiales. The "anisophyllous" leaves carry pinnules arranged in four rows. The strobili are bisporangiate and have disk-shaped sporophylls, each with one ring of 10-14 adaxial sporangia around the strobilus axis. Megaspores have an equatorial bulge. This new species expands the known diversity of Noeggerathiales. It grew in a peat-forming forest, thus changing earlier interpretations of the growth of noeggerathialean plants with anisophyllous pinnules.     

MEIOSIS IN VITRO: SPOROGENESIS IN CULTURED FERN PLANTS

Sporangia containing mature, functional spores can be induced to form on pinnae of Todea barbara sporophytes maintained in nutrient culture. Meiosis is initiated in the sporogenous cells and proceeds to completion in vitro with the formation of viable spores. Sporangial development, meiosis and the production of spores occur in plants which exhibit signs of senescence. Fertile leaves are characterized by a reduction in chlorophyll concentration and total cellular nitrogen when compared to sterile leaves. The data suggest that the process of sporogenesis may be correlated with a reduction in metabolic activity of the leaf.     

A New Morphological Interpretation of the Female Reproductive Organs in Ginkgo biloba L., with a Phylogenetic Consideration on Gymnosperms

The ovuliferous structure of Ginkgo biloba L. has been variously interpreted morphologically. As a result the systematic position and the relationship with other gymnosperms of this ancestral gymnosperm have long been under dispute. In the present paper, a brief survey of the main views as to the nature of the ovuliferous structure is givcn. Based on morphological and teratological data previously reported, a new interpretation is proposed. The essential points are summarized as follows: 1. In morphological essence, a fertile dwarf shoot with some ovuliferous structures in Ginkgo biloba L. might as a whole be nothing but a megasporophyll strobilus (female cone), which is shared actually by all the conifers in the gymnosperms. The fertile dwarf shoot has appearance extremely similar to that of the vegetative dwarf shoot, suggesting that in Ginkgo biloba L. the vegetative organs and the reproductive organs have not been yet well differentiated, and thus its megasporophyll strobilus might represent one of the most primitive compound strobilus types. 2. In Ginkgo biloba, the ovuliferous structure borne in the axil of a scale leaf (sometimes a normal leaf) on the dwarf shoot, together with the scale leaf itself, might be the homogenous organ corresponding to the bract-scale and seed-scale complex of the compound female strobilus of the typical conifers. The complex is a relatively isolated reproductive unit on the strobilus. The normal leaves and the scale leaves on the dwarf shoot might be equivalent to the bract-scales in the typical cones, though the normal leaves still retain the vegetative nature as the foliage leaves on the vegetative shoot. The stalk hearing ovules at its top might be equivalent to a seed-scale of the typical cones. 3. The megasporophyll strobilus in Ginkgo biloba, namely a whole fertile dwarf shoot as mentioned above, seems to show much more primitive characteristics than those of typical conifers. In this plant it is very difficult to distinguish the fertile dwarf shoot from the common vegetative dwarf shoot before reproduction time. Moreover, its megasporophyll strobilus often exhibits more atavistic abnormalities than those of other conifers. All the evidence indicates that the primitive ancestor of conifers might have had the fertile organs which might be of basically identical morphology as vegetative shoots, except that in the fertile organs there might exist numerous fertile leaves bearing one or many ovules. 4. The longer stalk of the ovuliferous structure in Ginkgo biloba might have come from mainly a secondary elongation growth of the seed scale, and only a little part of it might be the remains of the original shoot. The fork structure bearing ovules at the top of the stalk might be the rudementary part of the petioles of the only two extremely reduced megasporophylls. The collar around the base of the ovule might be a secondary protective structure. 5. A correct morphological interpretation of the female strobilus in Ginkgo biloba is doubtless of important significance for our better understanding of the evolution of the female reproductive organs in conifers. According to our interpretation mentioned above, together with the concept of the bractscale and seed-scale complex proposed in the present paper, which is mainly based on the concept of the seed-scale complex propose by Florin, here we put forward an evolutionary theory of the bract-scale and seed-scale complex. According to this theory, the female reproductive organs of the ancestral conifers should be very similar, as mentioned above, to the sterile foliage shoot except that the former might have some fertile leaves which could produce ovules at reproduction time. This ancestral female reproductive organ type might have had evolved towards two directions and thus formed two main evolutionary lines. One is represented by the genus Cycas and we may call it the Cycas Evolutionary Line (C-line), in which the megasporophyll strobilus is monopodial, with the fertile leaves and sterile bracts occurring directly on the main axis. The Cycadaceae is the only living gymnosperm member along this evolutionary line. The second line is represented by all the conifers including Ginkgo, which all have the structure of the bract-scale and seed-scale complex, and thus we called it the "Bract-scale and Seed-scale Complex Evolutionary Line" (BS-line). The members along this line have multipodial female strobilus, i.e. compound strobilus. On the main axis occur some sterile vegetative bracts. In the axils of some or most of the bracts occur the seed-scales. The seed-scales are actually the remains of the extremely, or smetimes completely reduced fertile shoots. Each part of the bractt-scale and seed-scale complex and the main axis of the strobilus could have undergone independent or correlated changes, and thus have had formed various types of strobilus which are found in the living conifers. 6. Our theory on the evolution of the bract-scale and seed-scale complex seems to support the division of all the gymnosperms into two major groups as proposed by Chamberlain, and is also in favour of the placement of Ginkgo biloba into the conifers as the most primitive member along BS-line. 7. Based on their similar morphological characters, it can be considered that Ginkgo biloba might have close relationships with the Nageiaceae, Ephedraceae, Welwitschiaceae and Araucariaceae. All these groups have multinerved leaves without costa. These living gymnosperms might have a more direct relationship withthe ancestral cordaites.     

Lycophytes from the Middle Triassic (Anisian) locality Kühwiesenkopf (Monte Prà della Vacca) in the Dolomites (northern Italy)

Abstract: Generally, lycophytes are not well represented in Anisian floras. Nonetheless, four different genera, each with one species, have been distinguished in the Anisian flora from Kühwiesenkopf (Monte Prà della Vacca), Italy. They were well preserved and yielded leaf cuticles in all four taxa and in situ spores in two of them. Lycopia dezanchei gen. et sp. nov. is the most common form; it is characterized by a dichotomising creeping prostrate rhizome (representing the primary shoot axis) from which arise aerial axes, apically bifurcated and covered with bundles of long leaves. This taxon cannot be attributed to any of the lycophyte orders, but most resembles Lycopodiales. Two representatives of the Isoetales have been found, of which Isoetites brandneri sp. nov. is abundant. This species is characterized by a short stem, which is unusual for this genus. In situ immature microspores and megaspores were found in some specimens. Lepacyclotes bechstaedtii sp. nov. has a quadrilobe corm with fertile scales inserted in whorls or slightly helicoidally. Short sterile leaves arise distally from the corm in some specimens. Selaginellales are very rare in the flora; Selaginellites leonardii sp. nov. is represented by a strobilus that yielded both micro‐ and megaspores. Some sterile fragments have been found associated, but never in organic connection.     

The influence of deer browsing on the reproductive biology of Canada yew (Taxus canadensis marsh.)

Summary Browsed Canada yew (Taxus canadensis) populations have a higher proportion of males and a lower proportion of monoecious plants than unbrowsed yew populations. The proportion of monoecious plants increases with time following protection from browsing suggesting that deer browsing causes male-biased sex expression in Canada yew. In contrast, results from comparing browsed and unbrowsed populations, exclosure studies, and browse simulation experiments indicate that strobilus ratios and phenotypic gender of browsed yews may be female-biased. In part, these results correspond to the influence of size on sex expression in Canada yew; small yews tend to be male, but if monoecious, have female-biased strobilus ratios. Large yews are monoecious, but have male-biased strobilus ratios. There is, however, no consistent relationship between size and gender in Canada yew, suggesting that in some circumstances, yews shift allocation to female function in response to browsing.     

Ontogeny of strobili, sporangia development and sporogenesis in Equisetum giganteum (Equisetaceae) from the Colombian Andes

Studies on the ontogeny of the strobilus, sporangium and reproductive biology of this group of ferns are scarce. Here we describe the ontogeny of the strobilus and sporangia, and the process of sporogenesis using specimens of E. giganteum from Colombia collected along the Rio Frio, Distrito de Sevilla, Piedecuesta, Santander, at 2200m altitude. The strobili in different stages of development were fixed, dehydrated, embedded in paraffin, sectioned using a rotatory microtome and stained with the safranin O and fast green technique. Observations were made using differential interference contrast microscopy (DIC) or Nomarski microscopy, an optical microscopy illumination technique that enhances the contrast in unstained, transparent. Strobili arise and begin to develop in the apical meristems of the main axis and lateral branches, with no significant differences in the ontogeny of strobili of one or other axis. Successive processes of cell division and differentiation lead to the growth of the strobilus and the formation of sporangiophores. These are formed by the scutellum, the manubrium or pedicel-like, basal part of the sporangiophore, and initial cells of sporangium, which differentiate to form the sporangium wall, the sporocytes and the tapetum. There is not formation of a characteristic arquesporium, as sporocytes quickly undergo meiosis originating tetrads of spores. The tapetum retains its histological integrity, but subsequently the cell walls break down and form a plasmodium that invades the sporangial cavity, partially surrounding the tetrads, and then the spores. Towards the end of the sporogenesis the tapetum disintegrates leaving spores with elaters free within the sporangial cavity. Two layers finally form the sporangium wall: the sporangium wall itself, with thickened, lignified cell walls and an underlying pyknotic layer. The mature spores are chlorofilous, morphologically similar and have exospore, a thin perispore and two elaters. This study of the ontogeny of the spore-producing structures and spores is the first contribution of this type for a tropical species of the genus. Fluorescence microscopy indicates that elaters and the wall of the sporangium are autofluorescent, while other structures induced fluorescence emitted by the fluorescent dye safranin O. The results were also discussed in relation to what is known so far for other species of Equisetum, suggesting that ontogenetic processes and structure of characters sporoderm are relatively constant in Equisetum, which implies important diagnostic value in the taxonomy of the group.     

VARIATION IN SEX EXPRESSION IN CANADA YEW (TAXUS CANADENSIS)

Sex expression was measured in several Canada yew (Taxus canadensis Marsh.) populations of the Apostle Islands of Wisconsin and southeastern Minnesota to determine the extent of variation within and among populations. Sex expression was recorded qualitatively (monoecious, male, or female) and quantitatively (by male to female strobilus ratios or standardized phenotypic gender). No discernible trends in differences in sex expression among populations or habitats were recorded. Trends in sex expression of individuals within populations were complex. Small yews tended to be male or, if monoecious, had female-biased strobilus ratios. Large yews were monoecious but had male-biased strobilus ratios. Phenotypic gender, recorded as relative maleness, however, was negatively, but weakly, correlated with plant size. Gender distribution in four of five populations was bimodal, suggesting that cosexual populations consist of male and female morphs. Strobilus ratios of individuals in Apostle Island populations showed significant annual variation, but gender for these same plants was significantly correlated from year to year. Annual adjustments in gender were most pronounced in small yews. The results indicate that relative investment in male and female reproductive structures by Canada yew individuals is responsive to environmental variation, but sex expression also has a proximate genetic component.     

枸杞花粉发育进程中花蕾和叶片物质代谢与育性的关系

以宁夏枸杞主栽品种'宁杞1号'的雄性不育株和可育株为研究材料,通过测定它们枝条生长速率,花粉不同发育时期花蕾和叶片的叶绿素、可溶性糖和脯氨酸含量以及硝酸还原酶活性,比较不育株与可育株在发育进程中物质代谢的差异.结果表明:在枸杞花粉发育进程中,不育株枝条生长速率快,花蕾和叶片的叶绿素含量高,而脯氨酸严重缺乏,可溶性糖含量和硝酸还原酶活性低,且各个发育阶段不育株和可育株均存在明显差异.可见,'宁杞1号'不育株物质代谢水平低,缺乏生理活性物质积累,使花粉发育有关基因的表达受到抑制,最终影响了其育性的正常表达.     

The Ogura sterility-inducing protein forms a large complex without interfering with the oxidative phosphorylation components in rapeseed mitochondria

The Ogura cytoplasmic male sterility causing protein, ORF138, was found to be part of a complex with an apparent size of over 750 kDa in the inner membrane of mitochondria of sterile plants. ORF138 did not colocalize with any of the oxidative phosphorylation complexes, nor did its presence modify their apparent size or amount, compared to samples from fertile isogenic plants. We attempted to detect potential proteins or nucleic acids that could be involved in the large ORF138 complex by 2D PAGE, immunoprecipitation and nuclease treatments of native extracts. All our results suggest that the ORF138 protein is the main, if not only, component of this large complex. The capacities of complexes I, II, IV, and ATP synthase were identical in samples from sterile and fertile plants. Isolated mitochondria from sterile plants showed a higher oxygen consumption than those from fertile plants. In vivo respiration measurements suggest that the difference in O₂ consumption measured at the organelle level is compensated at the cell/tissue level, completely in leaves, but only partially in male reproductive organs.     

基因工程雄性不育烟草及其温度敏感性

将含有抗溴苯腈基因bxn和雄性不育基因的重组载体pTA29-Barnase/bxn导入农杆菌(Agrobacterium tumefaciens)后转化烟草(Nicotiana tabacum L.),得到33个转基因植株。在27℃/23℃培养的16株中,有7株表现部分不育,另9株全部可育。而在20℃/15℃培养的17株中,12株表现不育,5株表现部分不育。部分不育的植株上同时开放可育花朵和不育花朵,不过其中的不育花朵中的花粉萌发活力很低。将在20℃/15℃条件下表现不育的12个不育株从20℃/15℃温室移至27℃/23℃温室后30d左右,其中9株表现程度不同的育性恢复现象:5株表现部分可育,另4株表现完全可育;但仍有3株表现雄性不育。雄性不育花朵的花丝变短,花药皱瘪,不散粉。细胞学观察证明,转基因植株的花药绒毡层降解提早于四分体时期,至单核小孢子时期降解殆尽。     

Phenology of 16 species of ferns in a subtropical forest of northeastern Taiwan

A knowledge of fern phenology promotes understanding of the biology and ecology of ferns. In this study, the phenology of 16 fern species in a subtropical broadleaf forest (N24°46′, E121°34′) in northeastern Taiwan was monitored from August 1997 to August 2001. Every fern produced both fertile and sterile leaves in each year of the study. Most fertile leaves emerged in February and March, whereas most sterile leaves emerged from May to September. Most leaves reached full expansion during April–July and died during April–August. The average life span of leaves ranged from 4.4 months to 30.3 months. In seven species, fertile leaves lived longer than sterile leaves, but this difference was significant only in Pteris wallichiana. In the other nine species, sterile leaves lived longer than fertile leaves, but the difference was significant only in Cyathea spinulosa, Plagiogyria dunnii, and Plagiogyria adanata. The ephemeral fertile leaves of the two dimorphic species died soon after releasing their spores, at only 5 months of age. However, their sterile leaves survived for over 22 months. The fertile leaves of the other 14 species remained green for almost 2 years after releasing their spores. Sterile leaves remained sterile throughout their lives. Spores matured in May–July and were released in June–August. After spore release, the sporangia detached. No leaf produced a second cohort of sori. Several phenological events, including sterile leaf emergence, leaf expansion and senescence, and spore maturation and release, were significantly positively correlated with temperature but not with precipitation, whereas the emergence of fertile leaves was weakly negatively correlated with temperature and precipitation. However, those correlations varied among different species. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Defining the limits of flowers: the challenge of distinguishing between the evolutionary products of simple versus compound strobili

Recent phylogenetic reconstructions suggest that axially condensed flower-like structures evolved iteratively in seed plants from either simple or compound strobili. The simple-strobilus model of flower evolution, widely applied to the angiosperm flower, interprets the inflorescence as a compound strobilus. The conifer cone and the gnetalean ‘flower’ are commonly interpreted as having evolved from a compound strobilus by extreme condensation and (at least in the case of male conifer cones) elimination of some structures present in the presumed ancestral compound strobilus. These two hypotheses have profoundly different implications for reconstructing the evolution of developmental genetic mechanisms in seed plants. If different flower-like structures evolved independently, there should intuitively be little commonality of patterning genes. However, reproductive units of some early-divergent angiosperms, including the extant genus Trithuria (Hydatellaceae) and the extinct genus Archaefructus (Archaefructaceae), apparently combine features considered typical of flowers and inflorescences. We re-evaluate several disparate strands of comparative data to explore whether flower-like structures could have arisen by co-option of flower-expressed patterning genes into independently evolved condensed inflorescences, or vice versa. We discuss the evolution of the inflorescence in both gymnosperms and angiosperms, emphasising the roles of heterotopy in dictating gender expression and heterochrony in permitting internodal compression.     

Identification of QTLs associated with male strobilus abundance in Cryptomeria japonica

It has become increasingly important to understand the factors controlling the abundance of male strobili in Cryptomeria japonica since allergic reactions to the species?? pollen have become prevalent in Japan. There is considerable inter-annual variation in the abundance of male strobili, so it is important to investigate and validate quantitative trait loci (QTL) for strobili abundance across different years. Data on third generation families derived from an individual that produces abundant male strobili were studied using Kruskal?CWallis tests and Bayesian regression analysis, resulting in the detection of a single major QTL that was observed over multiple years. This QTL explained between 10.4 and 26.5?% of the phenotypic variation in male strobilus abundance. The consistency and significance of this QTL??s effects suggest that it has a major role in male strobilus production in C. japonica, although we also detected other QTLs, indicating that strobilus production is subject to complex and multifactorial regulation. These QTL may also affect precocity because we were unable to separate their effects from the genetic variability in male strobilus production. The major QTL that we detected occurs in a region homologous to a QTL detected in a previous study examining trees with a different genetic heritage following artificial induction of male strobilus production. This result further supports the importance of the QTL detected in the present study. Identifying the important genes in this QTL will therefore significantly increase our understanding of the genetic mechanisms of pollen production in C. japonica.     

The morphogenesis of dimorphic pollen and anthers in Tripogandra amplexicaulis. Light microscopy and growth analysis

A characteristic of the genus Tripogandra is the presence of two dissimilar whorls of anthers. In T. amplexicaulis the short filamented anthers (S anthers) develop fertile, spheroidal pollen, the long filamented ones (L anthers) develop elongated spores, which degenerate prior to anthesis. Meiosis is regular in both types but occurs approximately two days later in the L anthers. Developmental traits of the L spores are a continuous, uniaxial extension and a sigmoid course of growth in volume accompanied by progressive vacuolarization and growth of starch grains and usually no division. The number of spores in the L anthers amounts to only 60 % of that in the S anthers, but the values for anther fresh weight and pollen sac volume of the former eventually exceed those of the latter and the relative growth rate in these variables is consistently higher in the L anthers. The relative rate in dry weight, however, is similar for both anthers and the absolute rate is clearly lower in the L anthers. These growth characteristics are reflected in a greater vacuolarization of both spores and the amoeboid tapetum in the L anthers. Cytological features of male sterile plants with hypotrophy of the tapetum are related to the sterility syndrome of the L anthers and a common hypothesis for the deviating features is presented.     

Aspects of Morphology of Phyllocladus hypophyllus

A study of Phyllocladus hypophyllus, a little-known species,reveals several interesting morphological characters. The leafy,rhomboid phylloclade is a complex of axillary, lateral branchingsystems with their fused scale leaves. The upper portion ofthe short, stalk-like structure of the male strobilus appearsto represent a suppressed phylloclade. The prominent nucellarbeak is developed to an extent far exceeding the cases whichhave been reported from other living conifers.     

辣椒胞质雄性不育系和保持系内源激素含量的比较

以2个辣椒品系(199807、199803)的胞质雄性不育系和相应保持系为实验材料,采用酶联免疫吸附法(ELISA)测定IAA、(Z ZR)、GA3和ABA等内源激素含量,用气相色谱分析仪测定乙烯(ETH)释放量,对辣椒胞质雄性不育系和相应保持系内源激素含量变化规律进行研究.实验结果表明:在四分小孢子之前,花药中的IAA含量不育系显著高于保持系,在四分小孢子时期花药和花蕾中的IAA含量出现转折,到花粉粒成熟期的花蕾和花药以及开花期叶片中的IAA含量均是不育系显著低于保持系;小孢子各发育时期花药以及花期叶片中GA3含量均是不育系高于保持系,但花粉粒成熟期化蕾中GA3含量为不育系低于保持系;小孢子不同发育时期的花药以及花期叶片中ABA含量始终足不育系显著高于保持系,而花粉粒成熟期花蕾中ABA含量不育系与保持系没有显著差异;花粉粒成熟期的花蕾和花期叶片中ETH释放量表现为不育系显著高于保持系.同时,花粉粒成熟期的花蕾、花药和叶片中IAA/ABA、(Z ZR)/ABA、GA3/ABA、IAA/GA3、(Z ZR)/GA3等5个激素的比值均有不育系低于保持系的趋势.本实验结果说明辣椒的育性表现与花器和叶片等组织中内源激素的含量变化有关,花药和花期叶片中IAA亏缺、GA3和ABA增加以及化蕾和叶片中ETH过度产生,都有可能导致辣椒雄性不育.     

A virus infection inMyriotrichia clavaeformis (Dictyosiphonales,Phaeophyceae) from Argentina

Summary Virus-infected plants ofMyriotrichia clavaeformis from the coast of Argentina are sterile and produce viras particles in lateral vesicles homologous to plurilocular sporangia of normal plants. Virions are released into the surrounding sea water and can infect swimming spores of healthyMyriotrichia plants. Virus particles are hexagonal in cross section with a diameter of 170–180 nm and have an envelope with an electron dense core. Similar viruses are known for several genera in the order Ectocarpales. This is the first record of an infectious agent in the order Dictyosiphonales, which contains thalli with more complex tissues and life histories.Dedicated to Prof. Dr. Dr. h.c. Eberhard Schnepf on the occasion of his retirement     

一个新的小麦核不育材料的发现和鉴定

从轮选可育株衍生的后代中发现一个雄性不育株,即P740不育材料。在P7 40不育材料第1、2、3次姊妹交后代中,可育株与不育株的分离比分别符合4:1、 7:5和15:13。在第2次姊妹交后代中可育株产生的40个株系中,7个株系的育性分离比是15:1,33个株系是3:1,二者约分别占1/7和6/7。以上结果表明,P740是一个双隐性基因控制的核雄性不育材料。本文提出了计算隐性核不育材料姊妹交后代育性分离比率的公式。 Abstract:A male sterile material was found in the progeny derived from a fertile plant in the population of recurrent selection.The ratios of fertile to sterile plants in three sib-mating of the male sterile material with fertile plants were to 4:1,7:5 and 15:13,respcctively.In the 40 plant lines derived from the fertile plants of second sib-mating population,33 lines approximated to the segregation ratio of 3(fertile):a double recessive nuclear male sterile material.A genetic pattern for calculation of fertile segregation in sib-mating progenies of recessive nuclear male sterile material was advanced in this paper.