Fertile Shoots Research Articles

ПРОДУКТИВНОСТЬ И ХОЗЯЙСТВЕННАЯ УРОЖАЙНОСТЬ ВИНОГРАДА ПРИ ПРИМЕНЕНИИ НЕКОРНЕВЫХ ПОДКОРМОК

The article presents the results of 6-year experi-mental studies to identify the varietal reaction of table and wine grapevine grades on systematic use of foliar top dressing with special complex fertilizers of various compositions. One-factor field experiments were carried out in fruit-bearing industrial vine plantations of the Black Sea (Abrau-Durso LLC, Novorossiysk) and Anapa-Taman (Temryuksky district, Vysheste-blievskaya station) viticulture zones of the Kras-nodar Territory. The object of the study was technical (Merlot, Chardonnay) and table (Au-gustine, Moldova) grapevine varieties. The set-ting and conducting of experimental studies were based on the recommended methodological manuals adopted in viticulture. As a result of the conducted studies, the positive effect of foliar top dressing on the main productivity indicators of all studied grapevine varieties (fruiting coeffi-cient, number and mass of bunches) was re-vealed. The advantage of the systematic use of organomineral fertilizer Maxifol of various brands is determined by the indicator of the number of fertile shoots per bush in the varieties Chardonnay and Augustine. The effectiveness of the humic preparation "Norm L" was revealed in Merlot, Augustine, Moldova varieties. Special complex fertilizers of various compositions used in vine plantations provided a total increase in yield in experiment No. 1 in the amount of 13.9 t/ha (Merlot variety) and 11.6 t/ha (Char-donnay variety) in 2016–2021; in experiment No. 2 – 29.9 t/ha (Augustine variety) and 27.0 t/ha (variety Moldova).

Spatial transcriptomics reveals light-induced chlorenchyma cells involved in promoting shoot regeneration in tomato callus

Callus is a reprogrammed cell mass involved in plant regeneration and gene transformation in crop engineering. Pluripotent callus cells develop into fertile shoots through shoot regeneration. The molecular basis of the shoot regeneration process in crop callus remains largely elusive. This study pioneers the exploration of the spatial transcriptome of tomato callus during shoot regeneration. The findings reveal the presence of highly heterogeneous cell populations within the callus, including epidermis, vascular tissue, shoot primordia, inner callus, and outgrowth shoots. By characterizing the spatially resolved molecular features of shoot primordia and surrounding cells, specific factors essential for shoot primordia formation are identified. Notably, chlorenchyma cells, enriched in photosynthesis-related processes, play a crucial role in promoting shoot primordia formation and subsequent shoot regeneration. Light is shown to promote shoot regeneration by inducing chlorenchyma cell development and coordinating sugar signaling. These findings significantly advance our understanding of the cellular and molecular aspects of shoot regeneration in tomato callus and demonstrate the immense potential of spatial transcriptomics in plant biology.

Florinanthus bussacensis sp. nov., a new cordaitalean cone from the Upper Pennsylvanian of Portugal

A new species of adpression cordaitalean cone is described from the Stephanian C (Upper Pennsylvanian) Vale da Mó “Formation” of the Buçaco Carboniferous Basin, central western Portugal. The macro- and micro-morphology of the new species, named Florinanthus bussacensis sp. nov., is described and its ontogenetic and palaeoecological significance assessed. The new cone species is erected on the basis of three primary axes with secondary fertile shoots with fimbriate apices. The number, linear-filiform shape and small size of the structures preserved on the distal parts of the scales suggests they represent pollen sacs, thus the new species F. bussacensis is considered to represent a male fructification. The new species is characterized by pollen sacs grouped in 4 to 5 clusters, composed of 4–7 basally fused sacs, and ovate to lanceolate-shaped sterile scales. The new cone seems to present different maturation states (mature to overmature) of its shoots, and its association with Cordaites leaves and Carpolites and Cardiocarpus seeds/ovules, suggests the new species was probably produced by the same parent plant species. The morphological and taxonomic diversity of the Pennsylvanian Cordaitaceae fructifications in western Variscan Euramerica remains largely unclear, due to the difficult recognition of these structures in the fossil record. This is the second record of a cordaitalean cone in the Carboniferous of Portugal, despite the abundance of cordaitalean remains (mainly of leaves, seeds, stems and roots) in its sequences. The difficult recognition of these structures in poor preservation conditions can easily make them go unnoticed and is more likely to be this the cause of their poor knowledge than a hypothetical limited record.

Structure of Equisetum variegatum (Equisetaceae) populations in natural and anthropogenic habitats

Many native plant species colonise anthropogenic habitats, but relatively little information is available on the status and development of their populations under unusual conditions. The most reliable information on the status and performance of plants in particular habitats is obtained through population studies. The study aimed to determine the characteristics of Equisetum variegatum populations occurring in natural and anthropogenic habitats. Nine coenopopulations of Equisetum variegatum occurring in natural and anthropogenic habitats were studied in four administrative districts (Kelmė, Lazdijai, Trakai and Varėna) of Lithuania. The ramet density, shoot height, total number of shoots and the number of fertile and sterile shoots and buds in a ramet were assessed. The density of Equisetum variegatum ramets was significantly higher in natural habitats than in anthropogenic habitats. The largest mean height of shoots was found in shrubland and shallow water habitats, whereas the largest mean number of all shoots, fertile shoots and buds in a ramet was recorded in dry sands. Old shoots in natural habitats comprised a significantly smaller portion (18.1%) of all shoots than in anthropogenic habitats (42.8%). Thus, all the studied traits can be used to evaluate the status of the populations. Long-term studies of Equisetum variegatum populations should be performed to determine how they change in response to the succession of natural and anthropogenic habitats. As the natural habitats of Equisetum variegatum decline, anthropogenic habitats may be considered the refugia for their populations.

Selaginella in Cretaceous amber from Myanmar

Selaginella (Selaginellales, Selaginellaceae) is the most speciose genus of lycophytes and, with approximately 750 recognized present-day species, also one of the largest genera of vascular plants. However, the evolutionary history of this species richness remains largely unresolved. Recent research suggests that Selaginella was diverse already in the mid-Cretaceous and shows that S. subg. Stachygynandrum dates back at least to the incipient Angiosperm Terrestrial Revolution some 100 million years ago. Here, we describe 20 new fossil-species of Selaginella based on fertile shoots and spores preserved in mid-Cretaceous Kachin amber from Myanmar and emend the previously described S. cretacea. Ten of the species (S. ciliifera, S. cretacea, S. grimaldii, S. heterosporangiata, S. longifimbriata, S. minutissima, S. ohlhoffiorum, S. patrickmuelleri, S. villosa, S. wangxinii) represent S. subg. Stachygynandrum because they possess anisophyllous strobili. The other eleven species have isophyllous strobili. Two of them (S. isophylla, S. wunderlichiana) are tentatively assigned to S. subg. Ericetorum, whereas the others (S. amplexicaulis, S. aurita, S. heinrichsii, S. konijnenburgiae, S. obscura, S. ovoidea, S. pellucida, S. tomescui, S. wangboi) cannot be placed into any fossil or extant subgenus. The fossils described in this study nearly duplicate the documented record of free-sporing plants from Kachin amber. The abundance and diversity of cryptogams, along with the absence of xerophytes among the taxa, is suggestive of constantly high humidity in the understory of the source forests of this amber. Citation: Schmidt A. R., Korall P., Krings M., Weststrand S., Bergschneider L., Sadowski E.-M., Bechteler J., Rikkinen J. & Regalado L. 2022: Selaginella in Cretaceous amber from Myanmar. – Willdenowia 52: 179–245. Version of record first published online on 22 September 2022 ahead of inclusion in August 2022 issue.

Using fertilization rates in semi-natural grasslands to produce seed for ecological restoration

To produce seeds of native species for ecological restoration, cultivating semi-natural grasslands can be a strategy that avoids the environmental impacts of conventional seed propagation and favours the conservation of species-rich grasslands. In a lowland grassland in northern Italy, the effects of three mineral fertilisation treatments (0–0–0, 0–54–108, and 192–108–216 kg ha−1 year−1 of N, P2O5, and K2O; abbreviations: 000, 0pk, and NPK) on seed production were studied in a fully randomised block design. Fertile shoots of flowering species were collected and analysed for seed content, and species phenology was recorded during field observations. The grassland environmental quality was described based on soil analyses and indices of natural (plant and insect richness) and aesthetic (flower colour) value. NPK produced the highest viable seed amount (59,375 m−2 year−1). The seed mixture was composed mostly of grasses (97%) and included the lowest species number (34). NPK also had the lowest environmental value. In 0pk, the nitrogen from legume rhizobial fixation allowed the production of an intermediate viable seed amount (28,485 m−2 year−1) with an intermediate forb seed percentage (14%) and the highest species number in the vegetation (42) and collected as seeds. In 000, the seed amount was the lowest (8310 m−2 year−1), but the species number (40) and forb percentage in the seed mixture (39%) were high. The natural and aesthetic values did not significantly differ between 0pk and 000. The P soil content increased strongly in NPK, whereas decreases or insignificant increases in P and K were recorded in 0pk and 000. Mineral 0pk fertilisation allows for relatively high seed production with high legume and forb richness by avoiding the distribution of nitrogen fertilisers that potentially impact the environment. This strategy seems to be a good option for producing environmentally friendly seed mixtures of many native species from semi-natural grasslands.

ГИНКГОФИТ ИЗ ЭСКИОРДИНСКОЙ СВИТЫ (ВЕРХНИЙ ТРИАС) ГОРНОГО КРЫМА

The article characterizes the first finding of a fertile ginkgophyte branch from the Upper Triassic deposits of the Crimean Mountains. A graphic reconstruction of this fertile shoot is given. The finding’s presumptive phylogenetic position in the evolutionary lineage of representatives of the Ginkgoales order is considered. The specimen studied is exhibited at the Lomonosov Moscow State University’s Earth Science Museum.

Leaf differentiation of extinct and remnant species of Zelkova in Western Eurasia

The genus Zelkova (Ulmaceae) has occurred in Europe and Southwest Asia since the Eocene represented mostly by the fossil species Z. zelkovifolia. Currently, relict populations of Z. abelicea, Z. sicula and Z. carpinifolia can be found in Crete, Sicily and the Euxino-Hyrcanian province, respectively. To reveal relationships between extinct and extant Zelkova species, we compared fossil Miocene leaves of Z. zelkovifolia and leaves of extant species using morphological leaf characteristics and statistical methods (Tukey’s test, discrimination analysis, principal component analysis, agglomeration). The fossil leaves of Z. zelkovifolia appeared more variable and generally intermediate between all three extant species. The lowest level of significant differences was found between Z. zelkovifolia and Z. abelicea in the leaves from fertile shoots and between Z. zelkovifolia and Z. sicula leaves from vegetative long shoots. The intermediate positions of fossil leaves of Z. zelkovifolia between leaves of Z. abelicea, Z. sicula and Z. carpinifolia could indicate that the extinct species was an ancestor of all three extant taxa. Consequently, this result suggests divergence between Z. abelicea, Z. sicula and Z. carpinifolia no earlier than the late Miocene and/or during the Pliocene.

VINE VARIETIES FOR WHITE WINES IN THE CLIMATE CONTEXT OF THE ODOBESTI VINEYARD, ROMANIA

Odobeşti Vineyard is one of the most famous and oldest Romanian vineyards, with a focus on white wines. To improve the existing assortment of varieties over time at the Research and Development Station for Viticulture and Vinification, Odobesti (RDSVV, Odobești), four vine varieties were obtained and approved: ʹŞarbaʹ (1972), ʹBăbească griʹ (1975), ʹMioriţaʹ (1980) and ʹVranceaʹ (2018), with superior quality and productive potential and a high capacity to capitalise on the edaphoclimatic conditions specific to this viticultual area. This study presents the behaviour of these varieties of vines in the climatic conditions of the Odobesti Vineyard in the period 2017–2021. The following parameters were studied and determined: the phenological spectrum of the vine, fertility and productivity (% fertile shoots, fertility coefficients, productivity indices), quantity and quality of grape production (grapes/vine, average bunch weight, grape production/vine, sugar content, total acidity and glucoacidimetric index). The data obtained were compared with the ʹSauvignon Blancʹ variety, which is widely grown in this area. The evolution of the vegetation phenophases was conditioned by the climatic factors during the study period. There was a tendency to shorten them due to the increase in air temperature values. The variety ʹVranceaʹ presented a high fertility potential (89.5% fertile shoots), the varieties ʹBăbească griʹ and ʹMiorițaʹ showed a higher productive potential than the control variety ʹSauvignon Blancʹ (6.06–6.12 kg/vine), and the variety ʹȘarbaʹ recorded the highest accumulations in sugars (230.5 g/L). In the climatic context of the Odobești Vineyard, the white wine varieties ʹȘarbaʹ, ʹBăbeasca griʹ, ʹMiorițaʹ and ʹVranceaʹ have demonstrated a valuable agrobiological and technological potential, comparable to that of the ʹSauvignon Blancʹ variety.

Effects of fertilisation on grass and forb gamic reproduction in semi-natural grasslands

Studying the effects of fertilisation on the seed production of grassland species can help understand the vegetation changes and biodiversity losses due to soil eutrophication. The seed production of fifteen grasses and seventeen forbs from a temperate hay meadow was studied under three fertilisation treatments: 0-0-0, 0-54-108 and 192-108-216 kg N, P2O5 and K2O respectively, per year. Fertile shoots collected at the seed maturation stage were analysed for all main traits of the gamic reproduction. On average, forbs produced more ovules and viable seeds per shoot (199 and 65, respectively) than grasses (112 and 35, respectively). Fertilisation increased the number of inflorescences per shoot in both grasses and forbs and had a limited but variable effect on germinability and viability in the two functional groups: viability increased in grasses but often decreased in forbs. This pattern resulted in 55% and 11% increases in viable seed production in grasses and forbs, respectively. At the higher level of fertilisation, shoot density was positively related to the number of viable seeds per shoot in grasses and to the seed size in forbs. These results highlight that the traits of the gamic reproduction can contribute to explain the relationship between soil nutrient richness and grassland species composition and richness.

Ancient noeggerathialean reveals the seed plant sister group diversified alongside the primary seed plant radiation

Noeggerathiales are enigmatic plants that existed during Carboniferous and Permian times, ∼323 to 252 Mya. Although their morphology, diversity, and distribution are well known, their systematic affinity remained enigmatic because their anatomy was unknown. Here, we report from a 298-My-old volcanic ash deposit, an in situ, complete, anatomically preserved noeggerathialean. The plant resolves the group's affinity and places it in a key evolutionary position within the seed plant sister group. Paratingia wuhaia sp. nov. is a small tree producing gymnospermous wood with a crown of pinnate, compound megaphyllous leaves and fertile shoots each with Ω-shaped vascular bundles. The heterosporous (containing both microspores and megaspores), bisporangiate fertile shoots appear cylindrical and cone-like, but their bilateral vasculature demonstrates that they are complex, three-dimensional sporophylls, representing leaf homologs that are unique to Noeggerathiales. The combination of heterospory and gymnospermous wood confirms that Paratingia, and thus the Noeggerathiales, are progymnosperms. Progymnosperms constitute the seed plant stem group, and Paratingia extends their range 60 My, to the end of the Permian. Cladistic analysis resolves the position of the Noeggerathiales as the most derived members of a heterosporous progymnosperm clade that are the seed plant sister group, altering our understanding of the relationships within the seed plant stem lineage and the transition from pteridophytic spore-based reproduction to the seed. Permian Noeggerathiales show that the heterosporous progymnosperm sister group to seed plants diversified alongside the primary radiation of seed plants for ∼110 My, independently evolving sophisticated cone-like fertile organs from modified leaves.

THE INFLUENCE OF HAIL AND TREATMENTS WITH AMINO-ACIDS ON THE FERTILITY AND BIOLOGIC BALANCE OF GRAPEVINES

Climatic accidents increase in frequency due to climatic changes. Hailstorms are typically localized events and are known few studies about their effect on grapevine. The objective of this study was to examine the vine vegetative balance responses to natural hail, registered when shoots were 10-15 cm height. Four grape cultivars (Vitis vinifera L.), two for red wine (Feteascǎ Neagrǎ, Pinot Noir) and two for white wine (Chardonnay, Tǎmȃioasǎ romȃneascǎ) were studied in Dealu Mare, one of the most known vineyards in Romania. Visibly, the extent of the hailstorm damage was great, enough to injure or remove about 90% of shoots growth till hail fall. Three treatments with Delfan Plus (amino-acids complex) were applied on grapevine canopy. Number of shoots/vine and number of fertile shoots/vine were counted and biologic balance of grapevine indexes were calculated. Our results indicated that natural hail affect significantly the number of fertile shoots. Delfan Plus treatments positively influenced the number of shoots and fertile shoots. Delfan Plus treatments had little influence on Recovery index, vine Balance indexes and Ensurance Coefficient after one single year of study. The capacity of recovery after hail fall, in this case, is more influenced by the grape cultivar. The present work is the first attempt to enhance our understanding on the vegetative responses of grapevines to the use of biostimulants and to natural hail, which is an extreme and complex natural phenomenon.

Seed production of semi‐natural grasslands: Amount and variability in an unfertilized upright brome and a fertilized tall oat‐grass meadow

AbstractSeed production is an important grassland feature, as it affects its persistence and botanical composition, and plays an essential role in complex plant–animal interactions. Species‐rich seed mixtures from grasslands can be utilized for ecological restoration. Previous studies used different methods to characterize seed production and did not consider all the main aspects involved; hence, they did not allow the complete understanding of the seed production. In this study the seed yield of an unfertilized Mesobromion and a fertilized Arrhenatherion meadow were investigated by considering all main reproductive traits and grassland species. In Arrhenatherion, the viable seed production was 24,000 seeds m−2 year−1, with a viable seed set of 21% (ovule number 115,000 m−2). These values were three times higher than those in Mesobromion. This difference was mainly attributed to different fertile shoot densities (758 vs. 358 m−2 for Arrhenatherion and Mesobromion respectively). Grasses transformed ovules to seeds (38%) more efficiently than forbs (11%). The standing seed yield at the first mowing was 35% and 45% of the produced seeds for Mesobromion and Arrhenatherion respectively. Because of late mowing, which is typical for Mesobromion meadows, the proportion of species found as seed at the first mowing was higher than that in Arrhenatherion. However, because many Mesobromion species were found to be poorly seed‐producing forbs with high spatial and temporal variabilities of seed yield, harvesting of seeds of all species would be more difficult, and a greater effort would be necessary if the collected seeds are to be used in ecological restoration.

Effects of tillage and sowing practices on plant growth, soil nutrient uptake and utilization of wheat after rice

From 2016 to 2018, a field trial on three tillage and sowing practices, deep rotary tillage before sowing (DRT), shallow rotary tillage with simultaneous sowing (SRT), and strip tillage under no tillage conditions along with sowing (NT), was conducted to evaluate shoot growth, soil nutrient uptake, and utilization of wheat (Triticum aestivum) after rice (Oryza sativa) in Guanghan, Sichuan Province, China. Compared with DRT, both SRT and NT improved tillering capacity and fertile shoot rate. In 2016-2017, grain yield did not differ among the treatments, whereas in 2017-2018, NT had significantly higher grain yield (10.9%) than DRT. Furthermore, the diffe-rence in dry matter accumulation among the treatments mainly occurred prior to wheat jointing. Total nitrogen uptake of plants was higher by 9.9% in NT than in DRT, whereas nitrogen harvest index was higher in DRT than in NT. Total phosphorus uptake was not different among the treatments. Total potassium uptake was higher in NT plants than in DRT plants. Overall, the results showed that compared with the traditional tillage practice (i.e., DRT), strip tillage practice along with sowing (i.e., NT) is an effective method for increasing grain yield and soil nutrient uptake for wheat after rice.

The architecture of Permian glossopterid ovuliferous reproductive organs

McLoughlin, S. & Prevec, R. 20 September 2019. The architecture of Permian glossopterid ovuliferous reproductive organs. Alcheringa XX, xxx–xxx. ISSN 0311-5518A historical account of research on glossopterid ovuliferous reproductive structures reveals starkly contrasting interpretations of their architecture and homologies from the earliest investigations. The diversity of interpretations has led to the establishment of a multitude of genera for these fossil organs, many of the taxa being synonymous. We identify a need for taxonomic revision of these genera to clearly demarcate taxa before they can be used effectively as palaeobiogeographic or biostratigraphic indices. Our assessment of fructification features based on extensive studies of adpression and permineralized fossils reveals that many of the character states for glossopterids used in previous phylogenetic analyses are erroneous. We interpret glossopterid fertiligers to have been borne in loose strobili in which individual polysperms represent fertile cladodes of diverse morphologies subtended by a vegetative leaf or bract. Polysperms within the group are variously branched or condensed with ovule placement ranging from marginal to abaxial, in some cases occurring on recurved branchlets or in cupule-like structures. Glossopterid polysperms of all types are fringed by one or two ranks of wing-like structures that may represent the remnants of megasporophylls that were, ancestrally, developed on the fertile axillary shoot. Glossopterid fertiligers have similarities to the condensed bract/ovuliferous scale complexes of conifer cones, but comparisons with Mesozoic seed-ferns are hindered by insufficient data on the arrangement and homologies of the ovule-bearing organs of the latter group. Nevertheless, glossopterid polysperms differ from the ovuliferous organs of Mesozoic seed-ferns by longitudinal versus transverse folding, respectively.Stephen McLoughlin* [steve.mcloughlin@nrm.se], Department of Palaeobiology, Swedish Museum of Natural History, Box 50007, 104 05 Stockholm, Sweden; Rose Prevec [r.prevec@am.org.za], Department of Earth Sciences, Albany Museum, 40 Somerset Street, Makhanda, 6139, Eastern Cape, South Africa, and Department of Botany, Rhodes University, PO Box 94, Makhanda, 6140, Eastern Cape, South Africa.

De novo shoot organogenesis during plant regeneration.

Plants exhibit remarkable regeneration capacity, ensuring developmental plasticity. In vitro tissue culture techniques are based on plant regeneration ability and facilitate production of new organs and even the whole plant from explants. Plant somatic cells can be reprogrammed to form a pluripotent cell mass called the callus. A portion of pluripotent callus cells gives rise to a fertile shoot via de novo shoot organogenesis (DNSO). Here, we reconstitute the shoot regeneration process with four phases, namely pluripotency acquisition, shoot promeristem formation, establishment of the confined shoot progenitor, and shoot outgrowth. Additionally, other biological processes, including cell cycle progression and reactive oxygen species metabolism, which further contribute to successful completion of DNSO, are also summarized. Overall, this study highlights recent advances in the molecular and cellular events involved in DNSO, as well as the regulatory mechanisms behind key steps of DNSO.

Omphalophloios wagneri sp. nov., a new sub-arborescent lycopsid from the middle Moscovian (Middle Pennsylvansian) of the Illinois Basin, USA

Described is a new species of sub-arborescent lycopsid, Omphalophloios wagneri sp. nov. from roof shale of the middle Moscovian (Bolsovian/Atokan) (Middle Pennsylvanian) Lower Block Coal in the Illinois Basin, Indiana, USA. Available material represents mostly fragments of 16 to >60 mm wide fertile axes that bear densely spaced sporangia, which are flattened due to compaction into disc-like shape, 2.5–3.1 mm in diameter. The outer sporangial cell wall layer displays a gradual transition from isometric cells in the central parts of adaxial and abaxial sporangial valves, to a narrow belt of elongated cells in the equatorial area, interpreted as a dehiscence zone. Micro- and megasporangia alternate in irregular patches, a single sporangium being attached adaxially to an extended sporophyll base. Cyperites-like sporophyll distal laminae are ~25 mm long at fertile shoot apices but become progressively longer (>110 mm) down the shoots. Based on size distribution of stems, fertile shoots are estimated to bifurcate at least five times, which suggests that O. wagneri formed a relatively dense crown. The entire habit of the plant is difficult to assess from existing material; however, the tree was probably small and interpreted as colonizing low lying to slightly raised peat swamps. Omphalophloios wagneri differs from all other adpression-based species of the genus in having the smallest sporangia and several orders of fertile-axis bifurcations. In situ megaspores of the Zonalesporites brassertii type also are different from all other Omphalophloios megaspores.

Are the male reproductive units of Juniperus drupacea Labill. (Cupressaceae s.str.) a compound, polyaxial inflorescence or a dense cluster of simple, uniaxial pollen cones?

The Juniperus Section Caryocedrus (Cupressaceae) is one of the three putatively monophyletic sections of the genus. It is monotypic, presented only by J. drupacea. Male reproductive units of this species show several distinct features distinguishing it distinctly from all other Juniperus species, including an inflorescence‐like arrangement of pollen cones, an increased number of microsporangia per microsporangiophore, and microsporangia attached to the stalk in up to three subsequent rows. The male reproductive units in J. drupacea have been investigated with paraffin technique and SEM. They are hypothesized to represent a distal cluster of densely arranged, simple pollen cones, which are interpreted as being derived from an ancestral condition that is still presented in species of the Section Juniperus. This is assumed to have occurred by a profound reduction of internodes of the fertile shoot axis carrying the pollen cone and a distal shift. The increased number of microsporangia per microsporangiophore may be a response to the decreasing number of pollen cones per tree compensating for the loss of pollen, that occurred during the evolution of inflorescence‐like male reproductive units.

Efficiency and allometry of seed production in grassland forbs: site and year comparative study in the Italian Eastern Pre-Alps

Forbs are important biodiversity components of grasslands and are often threatened by management intensification. As most forbs propagate predominantly by seed, knowledge of their seed regenerative traits would improve the conservation and restoration of forb-rich ecosystems. The main seed production traits of six forbs that are common in European species-rich grasslands were studied by collecting fertile shoots from different sites and over several years. Among sites and years, variability was high, particularly in the number of inflorescences per shoot, which affected ovule production more than any other trait. Relationships between inflorescence size and the number of ovules were mainly negatively allometric or almost so, with lower flower densities in larger inflorescences. The average ovule-to-seed transformation efficiency was 58%. There was significant variation among collections of the same species, and even more between species. Species with a low ovule-to-seed transformation efficiency generally exhibited compensatory, high seed viability. Large inflorescences had high ovule to seed utilization values, probably because of better nutrient conditions. Seed germinability (average, 30%) was much lower than seed viability (average, 54%); therefore, seed dormancy was an important feature of the species studied.

Two New Conifers from the Early Cretaceous of the Rajmahal Basin, India: Implications on Palaeoecology and Palaeogeography

The occurrence of a diverse range of conifers and bennettitales is characteristic of the macroflora from the Early Cretaceous of the Rajmahal Basin, India. In the present paper two new conifer taxa assigned to the families Cupressaceae and Podocarpaceae are described from the intertrappean sediments of the Rajmahal Formation in Jharkhand State. The remains are silicified, composed of sterile and fertile shoots, detached leaves and dispersed seeds. The specimens have been placed under the family Cupressaceae, are described as Hirandubia cupressoides gen. et sp. nov., a species that shows close affinity with the extant cupressaceous genera Platycladus Spach and Chamaecyparis Spach, and provides the first comprehensive record of Cupressaceae from the Early Cretaceous of India. Elatocladus-type shoots and detached leaves have also been recovered. In association with the shoot fragments and detached leaves, a new kind of podocarpaceous dispersed seed designated as Podocarpospermum podocarpoides sp. nov., occurs together with a microsporangiate cone Podostrobus rajmahalensis (Rao) Rao and Bose, having in situ bisaccate pollen grains. These remains are all attributed to the family Podocarpaceae and have some similarities to extant Podocarpus L'Herit ex Pers. Based on the occurrence of a diverse range of conifers and bennettitales in the Early Cretaceous flora of Rajmahal Formation interpretation on palaeoecology and palaeogeography has been done.