Diversity and significance of late cretaceous permineralized plant remains from Hokkaido,Japan

Middle to Late Cretaceous permineralized plants hitherto described from Hokkaido, Japan are summarized. The fossil flora comprises fungi, ferns, gymnosperms and angiosperms. Many modern fern families have been recognized including Anemiaceae, Cyatheaceae, Dennstaedtiaceae, Gleicheniaceae Loxsomaceae, Lygodiaceae and Matoniaceae. Gymnosperms are most abundant in the flora. Some recently-found materials are tentatively introduced with brief comments emphasizing their morphological and taxonomical significance. A bisporangiate flower ofCycadeoidella japonica Ogura shows fine internal anatomy and provides evidence that the cycadeoidalean ovule was a cupulate, unitegmic structure. Vascular tracheids in the synangial wall support the evolution of cycadeoidalean synangia from Paleozoic seed-fern synangia. A new gymnosperm female fructification has a thick envelope comparable to an angiosperm carpel around a large seed. The angiosperms contain various morphologies that require further extensive study.     

Singular taphonomic record of a wildfire event from middle Albian deposits of Escucha Formation in northeastern of Spain

A fossil plant assemblage composed of a great amount of macro, meso and microscopical charcoalifed remains occur in a single layer in Albian deposits of the Escucha Formation in northeastern Spain. This assemblage consists fundamentally of fragments of pinnae and pinnules corresponding to the Matoniaceous ferns Weichselia reticulata and Phlebopteris dunkeri also with some gymnosperm wood remains. The features of both the fossil plants and the deposit itself indicate accurate paleoenvironmental conditions related to the action of wildfires over the vegetation growing in freshwater swamp plains during Albian in Southwestern Eurasia.     

Permian ginkgophyte fossils from the Dolomites resemble extant <Emphasis Type="Italic">O-ha-tsuki</Emphasis> aberrant leaf-like fructifications of <Emphasis Type="Italic">Ginkgo biloba</Emphasis> L

Background  

Structural elucidation and analysis of fructifications of plants is fundamental for understanding their evolution. In case of Ginkgo biloba, attention was drawn by Fujii in 1896 to aberrant fructifications of Ginkgo biloba whose seeds are attached to leaves, called O-ha-tsuki in Japan. This well-known phenomenon was now interpreted by Fujii as being homologous to ancestral sporophylls. The common fructification of Ginkgo biloba consists of 1-2 (rarely more) ovules on a dichotomously divided stalk, the ovules on top of short stalklets, with collars supporting the ovules. There is essentially no disagreement that either the whole stalk with its stalklets, collars and ovules is homologous to a sporophyll, or, alternatively, just one stalklet, collar and ovule each correspond to a sporophyll. For the transition of an ancestral sporophyll resembling extant O-ha-tsuki aberrant leaves into the common fructification with stalklet/collar/ovule, evolutionary reduction of the leaf lamina of such ancestral sporophylls has to be assumed. Furthermore, such ancestral sporophylls would be expected in the fossil record of ginkgophytes.     

Natural Occurrence ofChondrostereum purpureumin Relation to Its Use as a Biological Control Agent in Canadian Forests

The incidence of natural fructification ofChondrostereum purpureumwas estimated quantitatively on southern Vancouver Island during two winter seasons in randomly located 1000-m²plots and compared with potential added fructification that might occur as a result of using the fungus to control stump-sprouting of hardwood weeds in young forest stands. Fructification was surveyed in forests as well as in urban or agricultural areas by estimating the surface areas of woody substrates covered with basidiocarps. In addition to random plots, estimates were made also in locations where the fungus would be expected to occur (woodpiles, silvicultural thinnings, and killed trees). Basidiocarps were found throughout the area in various types of forest cover as well as in urban or agricultural situations. The amount of added fructification through the use of the fungus as a biological control agent was determined from inoculated plots as well as from calculated stump-surface areas developed from published stand-density data. Added fructification was multiplied by a factor representing the maximum biological control frequency in order to compare added fructification with natural fructification values. From the various calculations, it was determined that the added fructification ofC. purpureumis of the same order of magnitude as naturally occurring levels or even lower. In addition, there is a distinct geographical separation between predominantly forestry and predominantly settled areas where fruit and ornamental trees are cultivated. Accordingly, it was concluded that using the fungus as a biological control agent in forestry is not likely to pose a significant threat to fruit growing and commercial forests.     

EARLY ANGIOSPERM REPRODUCTION: CALODA DELEVORYANA GEN. ET SP. NOV., A NEW FRUCTIFICATION FROM THE DAKOTA FORMATION (CENOMANIAN) OF KANSAS

A new angiosperm fructification, Caloda delevoryana, is described from the Cenomanian age Dakota Formation of central Kansas. It consists of a long, narrow, main axis with numerous secondary axes arranged helically around the main axis. These secondary axes are each terminated in a small receptacle bearing numerous conduplicate carpels. No evidence of a perianth or androecium was found. This fructification bears some similarity to a number of different modern orders, such as the Hamamelidales, Alismatales, Najadales, and Piperales, and families, particularly the Platanaceae and the Aponogetonaceae, but cannot definitely be assigned to any modern taxon within the angiosperms. C. delevoryana exhibits several characters traditionally assumed to be primitive in the angiosperms, and several other features of this fossil are proposed as primitive in the evolution of angiosperms. This floral axis, with its compact mass of numerous secondary axes bearing very small fruits and seeds, may be the product of reduction through diminished growth of internodes and carpels, and elaboration through increased repetition of floral modules. This record adds to the rapidly growing body of paleobotanical data on early angiosperm reproductive structures, which should prove important in the assessment of the extent and direction of angiosperm evolution.     

Novel double wing morphology revealed in a South African ovuliferous glossopterid fructification: Bifariala intermittens (Plumstead 1958) comb. nov.

Plumstead (1958) established Hirsutum intermittens for glossopterid fructifications with a putative bi-sporangiate, bi-valved architecture but later workers reinterpreted the fossils predominantly as ovuliferous, dorsiventrally flattened, bilaterally symmetrical organs, with a central seed-bearing receptacle and a single finely striate peripheral wing. The wing morphology is central to both the generic and specific diagnoses. New analysis of many South African impressions reveals the presence of two superposed wings flanking the flattened receptacle of H. intermittens. One wing is radially fluted and striated with rounded basal lobes, whereas the other has distinctive distally arched striations and an extended apex. The double-winged structure is unlike that of other glossopterid fertile organs and probably accounts for Plumstead's misinterpretation of the fructification as bivalvate. The specimens are assigned to Bifariala intermittens (Plumstead, 1958) comb. nov., emend. Prevec because Hirsutum is unacceptable according to ICBN rules. Revelation of novel architectural details highlights the value of impression fossils for resolving the gross structure of gymnosperm fertile organs. The newly defined second wing provides an additional character to be considered in the search for homologies of the ovule outer integument or cupules in derived seed-plants.     

Studies of Fossil and Modern Spore Wall Biomacromolecules using13C Solid State NMR

A range of Carboniferous lycophyte megaspore exines have beeninvestigated using¹³C magic-angle spinning nuclear magneticresonance (MAS NMR) spectroscopy. Their composition differsconsiderably from sporopollenin obtained from an extant lycophyte.The differences observed result in part from varying degreesof diagenesis. Fossil fern spores, gymnosperm megaspore-membranes and pollenhave also been examined. These show a similar composition tothe fossil lycophyte megaspores. The constituent material ofall of these exines differs considerably from the sporopolleninobtained from comparable extant samples. Despite the changesin composition observed on fossilisation, differences in compositionbetween the major groups of plants may be preserved to someextent in the fossil material. Walls of the fossil prasinophyceanalgal cystTasmanites have been examined and these show a greatersimilarity to fossil cuticle and algaenans than to sporopollenins. The effect of oxidative maceration on fossil and modern sporopolleninshas also been investigated. The main influence of oxidativemaceration is the removal of unsaturated carbon environmentssuch as aromatics; this causes fossil spores to be more susceptibleto oxidative maceration than the modern exines. Heating of modernexine material models the alteration of exines by diagenesis.The changes that occur on heating an extant sample to 150–225°Cgive a chemical composition that is similar to those of thefossil sporopollenins. ¹³C solid state NMR; spores; pollen; fossil; Carboniferous lycopsids; ferns; pteridosperm; gymnosperm; oxidative maceration; heating; thermal maturation     

Molecular evidence of cycad seed predation by immature Aulacoscelidinae (Coleoptera: Orsodacnidae)

Adult beetles in the small subfamily Aulacoscelidinae (superfamily Chrysomeloidea) are known to feed on the foliage and juices of New World cycads (Order Cycadales; family Zamiaceae), but the habits of larvae have long remained a mystery. We provide the first direct evidence that Aulacoscelidinae larvae feed on and develop within the megagametophyte of the Mesoamerican cycad, Dioon merolae (Zamiaceae). Phylogenetic analyses based on partial DNA sequences from 3 genes recover a cycad seed‐feeding larva proposed to belong to Aulacoscelidinae. These observations reveal a more intimate feeding relationship between Aulacoscelidinae and their New World cycad host plants than was previously recognized. Further, adult Aulacoscelidinae have long been noted to resemble Jurassic fossil chrysomeloids in the extinct subfamily Protoscelidinae. The molecular, morphological, ecological and fossil data reported herein are broadly compatible with an early association between Aulacoscelidinae and their gymnosperm hosts.     

A surface microrelief on the leaves of Glossophyllum florinii (?Ginkgoales) from the Upper Triassic of Lunz,Austria

The cuticles of many extant seed plants display distinct surface microreliefs, which represent adaptations to certain habitat conditions or mechanical defences against herbivores and phytopathogenic microorganisms. Although microreliefs have variously been noted in fossil cuticles, hypotheses relating to the effectiveness of these structures in fossil plants have not been advanced to date. A surface microrelief composed of longitudinally orientated idiocuticular striae occurs on the leaves of the enigmatic Carnian (Late Triassic) gymnosperm (?ginkgophyte) Glossophyllum florinii Kräusel from the Northern Calcareous Alps of lower Austria. Most striae originate from the tips of the papillae on the stomatal subsidiary cells. The G. florinii surface microrelief may have (1) reduced leaf wettability, (2) produced or enhanced the self‐cleaning effect of the leaf, (3) prevented the formation of a water film on the leaf surface, and/or (4) mechanically stabilized the leaf. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 153 , 87–95.     

Variability of ligninolytic enzyme activities in basidiospore isolates of the fungusPleurotus ostreatus in comparison with that of protoplast-derived isolates

Variability of production of all tested ligninolytic enzymes (laccase, peroxidase and manganese-dependent peroxidase) was substantially higher in isolates derived from basidiospores of strain F6 of the white-rot basidiomycetePleurotus ostreatus than the relatively low variability of the dikaryotic mycelial colonies of this strain, and also higher than the variability of protoplast-derived isolates of the same strain. The difference was caused mainly but not completely by the monokaryotic nature of the isolates. To reach the best fructification of the fungus, two fructification media were chosen from twenty two tested and a modified technique of fructification was used.     

Fossil pollen records of the problematical primitive angiosperm familyLactoridaceae in Australia

Microfossils which matchLactoris (Lactoridaceae) pollen more closely than those of any other living angiosperm occur in Campanian to Paleogene sediments around the margins of Australia. These are referred to the fossil genus Lactoripollenites (Zavada & Benson 1987). A species belonging to the same genus occurs in older (Turonian-Santonian) deposits off southern Africa but Australian specimens represent not only the most southern, but also the youngest known (Oligocene) records to date. Our data support suggestions that theLactoridaceae were widespread across the Southern Hemisphere during the Late Cretaceous (Lammers & al. 1986,Zavada & Benson 1987). An homology between gymnosperm sacci and the saccus-like structures found in Lactoripollenites and some specimens ofLactoris pollen is contested, as is the use of (anasulcate) apertures to support the primitive position of the family.     

Cenozoic extinctions account for the low diversity of extant gymnosperms compared with angiosperms

We test the widely held notion that living gymnosperms are 'ancient' and 'living fossils' by comparing them with their sister group, the angiosperms. This perception derives partly from the lack of gross morphological differences between some Mesozoic gymnosperm fossils and their living relatives (e.g. Ginkgo, cycads and dawn redwood), suggesting that the rate of evolution of gymnosperms has been slow. We estimated the ages and diversification rates of gymnosperm lineages using Bayesian relaxed molecular clock dating calibrated with 21 fossils, based on the phylogenetic analysis of alignments of matK chloroplast DNA (cpDNA) and 26S nuclear ribosomal DNA (nrDNA) sequences, and compared these with published estimates for angiosperms. Gymnosperm crown groups of Cenozoic age are significantly younger than their angiosperm counterparts (median age: 32 Ma vs 50 Ma) and have long unbranched stems, indicating major extinctions in the Cenozoic, in contrast with angiosperms. Surviving gymnosperm genera have diversified more slowly than angiosperms during the Neogene as a result of their higher extinction rate. Compared with angiosperms, living gymnosperm groups are not ancient. The fossil record also indicates that gymnosperms suffered major extinctions when climate changed in the Oligocene and Miocene. Extant gymnosperm groups occupy diverse habitats and some probably survived after making adaptive shifts.     

Morphological and molecular data on the origin of angiosperms: on a way to a synthesis

Molecular phylogenetic data have drastically changed the views on the phylogeny of higher plants. All the extant gymnosperms were asserted as a monophyletic group opposed to the highly isolated angiosperms. The 'Anthophyte Theory' was thus rejected. The identification and analysis of gymnosperm orthologues of genes regulating flower development in angiosperms resulted in the formulation of the 'Mostly Male Theory' of the evolutionary origin of flower; this theory does not contradict the concept of monophyly of all the extant gymnosperms. The Mostly Male Theory assumes that the origin of angiosperms was caused by a loss of the Needle family gene that effected ovuliferous (female) organs and the translocation of the ovules onto the adaxial side of some of the (male) leafy microsporangiophores. Having acquired ovules, the former microsporangiophores started evolving into the carpels. The prerequisite bisexual design of the ancestral fructification thus becomes unnecessary. Indeed, this assumption suggests the deriving of Angiosperms from any gymnosperm plant with leafy microsporangiophores. The problem of carpel origin has subsequently changed to some degree into the problem of the origin of the bitegmic anatropous ovule presumably inherent in ancestral Angiosperms. The Mostly Male Theory consideredeither Corystospermataceae (= Umkomasiaceae) or Caytoniaceae to be the forerunners of such an ovule. Yet the capsules of Corystospermataceae distinctly differ from angiosperm ovules in the locations of their adaxial/abaxial sides, while Caytoniaceae had no leafy microsporangiophores. This inconsistency suggests that functions of the Needle family regulatory genes in Gymnosperms should be much better understood to appraise properly both the possibilities and the consequences of their hypothetical loss by the emerging angiosperms. Moreover, the extant gymnosperm groups are actually held as monophyletic and contrasted to Angiosperms on the basis of analysing the unrepresentative scant remnants of these, mostly extinct, taxa. Therefore, traditional botanical and paleobotanical data should not be rejected. In any case, Meyen's idea angiosperms origin from Bennettitales is worth being retained as a hypothesis to be tested with new results of both paleobotany and molecular biology.     

Degradation dynamics of lignocellulose materials by wood-rottingPleurotus fungi

When grown on wheat straw,Pleurotus decomposes both the lignin and the cellulose components of the substrate. The course of degradation differs during growth and fructification. The losses of dry mass during growth were about 20 %. The absolute amount of hemicelluloses, cellulose and lignin was decreasing. Hemicelluloses and lignin were degraded at a higher rate than cellulose. The total mass losses of the substrate after fructification were 32 to 45 %. Cellulose was consumed at a higher rate than lignin.     

In vitro development of parthenocarpic fruits of Crocus sativus L.

In vitro development of parthenocarpic fruits of Crocus sativus L. was induced by culturing ovaries on MS agar medium supplemented with growth-regulators (2,4-D, GA₃ and BAP). Amongh these, 2,4-D was the most effective in promoting fructification. The fructigenic activity was independent of both the stage at which the ovaries were excised (before, during or after anthesis) and pollination of the stigmas. Unlike the above compounds, abscisic acid inhibited fructification.     

Regreening in spathes of Zantedeschia after anthesis: its physiology and control by fructification and hormones

The mature pigmented spathe of Zantedeschia is characterized by a developmental process, wherein the spathe regreens after anthesis and prior to senescence of the inflorescence. Previous research has shown that spathe regreening involves redifferentiation of chloroplasts and re‐accumulation of chlorophyll, but the detailed physiological changes associated with regreening are still largely unknown. Using Zantedeschia aethiopica and the Zantedeschia pentlandii variety ‘Best Gold’ as models, this study explores the physiological mechanism and possible roles of fructification, 6‐benzylaminopurine (BAP) and gibberellin (GA₃) in induction or progression of spathe regreening. Application of BAP stimulated regreening in spathe tissue of ‘Best Gold’ by enhancing accumulation of carotenoid and chlorophyll, and also increasing stacking of grana. In contrast, GA₃ retarded formation of double‐membrane lamella during chloroplast redifferentiation, thus delaying the onset of regreening. We suggest that these actions of BAP and GA₃ have a synergistic effect in delaying the onset of regreening in ‘Best Gold’ so that when applied together retardation of chlorophyll accumulation, chloroplast redifferentiation and accumulation of carotenoids were enhanced. The elimination of fructification did not prevent the occurrence of regreening in either Zantedeschia model plants, indicating that fructification was not a prerequisite for the induction of regreening. It is still unclear how regreening in Zantedeschia is triggered. We propose that the onset of regreening in Zantedeschia is likely to be a genetically programmed event.     

Plant evolution: pulses of extinction and speciation in gymnosperm diversity

Living gymnosperms represent the survivors of ancient seed plant lineages whose fossil record reaches back 270 million years. Two recent studies find that recent pulses of extinction and speciation have shaped today's gymnosperm diversity, contradicting the widespread assumption that gymnosperms have remained largely unchanged for tens of millions of years.     

Amber from the Alpine Triassic of Lunz (Carnian,Austria): a classic palaeobotanical site

Amber from the Triassic (Carnian) of Lunz, a locality which has produced a rich and famous fossil flora, was analysed using UV‐B‐fluorescence, attenuated total reflectance Fourier transform infrared spectroscopy (ATR‐FTIR) and pyrolysis gas chromatography mass spectroscopy (Py‐GC‐MS). The amber is classified as a class Ib resinite based on its chemical composition, which is characterized by bicyclic products derived from a regular labdatriene structure and the absence of succinic acid. The presence of diterpenoids and absence of triterpenoids is clear evidence of a gymnosperm origin for the Lunz amber, and the prevalence of sesquiterpenoids and diterpenoids point to a conifer family as a possible botanical source. In search of amber attached to identifiable floral remains we have screened new and historical collections of the macroflora from a number of localities of the Lunz area using UV‐B, and describe a striking yellow UV‐B‐fluorescence of cuticles of pteridosperms, ginkgophytes and conifers. This varies with the diagenetic state of the sediment and may be lost altogether. Detectable amounts of fluorescent compounds were observed in gymnosperm taxa, but not in any ferns and only very weakly in horsetails. This underlines that fluorescent compounds are derived from gymnosperm plants, mostly likely arising secondarily from cyclic hydrocarbons by desaturation during diagenesis as a parallel process in amber as well as in cuticles.     

A new geranylgeranyl diphosphate synthase gene from Ginkgo biloba, which intermediates the biosynthesis of the key precursor for ginkgolides.

Geranylgeranyl diphosphate synthase (GGPPS, EC: 2.5.1.29) catalyzes the biosynthesis of geranylgeranyl diphosphate (GGPP), which is a key precursor for ginkgolide biosynthesis. Here we reported for the first time the cloning of a new full-length cDNA encoding GGPPS from the living fossil plant Ginkgo biloba. The full-length cDNA encoding G. biloba GGPPS (designated as GbGGPPS) was 1657bp long and contained a 1176bp open reading frame encoding a 391 amino acid protein. Comparative analysis showed that GbGGPPS possessed a 79 amino acid transit peptide at its N-terminal, which directed GbGGPPS to target to the plastids. Bioinformatic analysis revealed that GbGGPPS was a member of polyprenyltransferases with two highly conserved aspartate-rich motifs like other plant GGPPSs. Phylogenetic tree analysis indicated that plant GGPPSs could be classified into two groups, angiosperm and gymnosperm GGPPSs, while GbGGPPS had closer relationship with gymnosperm plant GGPPSs.     

Use of various coffee industry residues for the cultivation of Pleurotus ostreatus in solid state fermentation

Studies were carried out to evaluate the feasibility of using coffee industry residues, viz. coffee husk, coffee leaves and spent coffee ground as substrates in solid state fermentation (SSF) to cultivate edible mushrooms Pleurotus. Eight strains of Pleurotus ostreatus and two strains of Pleurotus sajor‐caju were screened on a medium prepared from aqueous extract of coffee husk and agar. Based on best mycelial growth (9.68 mm/day) and biomass production (43.4 mg/plate in 9 days at 24°C), the strain P. ostreatus LPB 09 was selected for detailed studies. SSF was carried out using these substrates under different moisture conditions (45–75%) and spawn rates (2.5–25%). In general, although a 25% spawn rate appeared superior, the 10% spawn rate was recommended for all the three substrates in view of the process economics, as there was not any significant difference in the increase with 10 to 15%. The ideal moisture content for mycelial growth was 60–65% for coffee husk and spent coffee ground, and 60–70% for coffee leaves. The biological efficiency (BE), which is defined as the ratio of the weight of fresh fruiting bodies to the weight of dry substrate, multiplied by 100, and which indicates the fructification ability of the fungus for utilizing the substrate, was best with coffee husk. With coffee husk as the substrate, the first fructification occurred after 20 days of inoculation, and the biological efficiency reached about 97% after 60 days. When coffee leaves were used as the substrate, no fructification was observed even upon prolonged cultivation. With spent ground as the substrate, the first fructification occurred 23 days after inoculation and the biological efficiency reached about 90% in 50 days. There was a significant decrease in the caffeine and tannin contents (61 and 79%, respectively) of coffee husk after 60 days. It was remarkable to observe that caffeine was adsorbed onto the fruiting body (0.157%), indicating that it was not completely degraded by the fungal culture. However, no tannins were found in the fruiting body, indicating that the fungal strain was capable of degrading them. The results showed the feasibility of using coffee husk and spent coffee ground as substrates without any pre‐treatment for the cultivation of edible fungi in SSF, and provided one of the first steps towards an economical utilization of these otherwise unutilized or poorly utilized residues.