Male Plants Research Articles

Inflorescence development in female cannabis plants is mediated by photoperiod and gibberellin.

In cannabis seedlings, the initiation of solitary flowers is photoperiod-independent. However, when cannabis reaches the adult stage, short-day photoperiod (SD) triggers branching of the shoot apex and a reduction in internode length, leading to development of a condensed inflorescence. We demonstrate that SD affects cannabis plants in two distinct phases: the first includes rapid elongation of the internodes and main stem, and occurring from Day 5 to Day 10 of plant cultivation under SD; in the second phase, elongation of newly developed internodes ceases, and a condensed inflorescence is formed. Exposure of plants to alternating photoperiods revealed that inflorescence onset requires at least three consecutive days of SD, and SD is consistently required throughout inflorescence maturation to support its typical condensed architecture. This photoperiod-dependent morphogenesis was associated with a decrease in gibberellin (GA4) and auxin levels in the shoot apex. Reverting the plants to a long-day photoperiod (LD) increased GA4 and auxin levels, leading to inflorescence disassembly, internode elongation, and subsequent resumption of LD growth patterns. Similar developmental patterns were observed under SD following the application of exogenous GA (and not auxin), which also impeded inflorescence development. Nevertheless, additional studies will help to further evaluate auxin's role in these developmental changes. We propose a crucial role for GA in sexual reproduction and inflorescence development in female cannabis by mediating photoperiod signaling in the inflorescence tissues.

Characterization of Male Flower Induction by Silver Thiosulfate Foliar Spray in Female Cannabis at the Middle Reproductive Stage for Breeding.

Cannabis (Cannabis sativa) is a versatile crop belonging to the Cannabaceae family, and is dioecious, typically with separate male and female plants. The flowers of female plants, especially the trichomes, accumulate relatively higher contents of cannabinoids compared with those of male plants. For this reason, to obtain seeds that are genetically female, it is desirable to induce the development of male flowers on a female plant that produces genetically female haploid gametes. Silver thiosulfate (STS) is a highly effective chemical for male flower induction. We investigated male flower induction in three commercial cultivars of female cannabis (Spectrum303, SuperwomanS1, and CBGambit) regarding the treatment frequency, stage of application, and concentration of STS applied as a foliar spray. All three cultivars showed adequate induction of male flowers in response to 1.5 mM STS applied at the early reproductive stage. In particular, SuperwomanS1 was most highly responsive to induction of male flowers, even when treated with 0.3 mM STS at the early reproductive stage. Treatment with three applications of STS was more effective compared with a single application, but a single application of 1.5 mM STS at the early reproductive stage was sufficient for male flower induction. A single STS application during the middle stage of reproductive growth was inadequate for induction of male flowers. However, 6 weeks after three applications of STS, CBGambit exhibited approximately 54% male flower induction at 0.3 mM STS, Spectrum303 showed approximately 56% induction at 3 mM STS, and SuperwomanS1 yielded approximately 26% induction at 1.5 mM (expressed as percentage of total number of individuals with the induced male flowers). Pollen stainability tests using KI-I2 solution and Alexander's staining showed high pollen viability with over 65% at different single STS concentrations, indicating that pollen grains induced by STS have sufficient viability for the self-pollination. This study demonstrated that different cultivars of cannabis respond diversely to different STS concentrations and highlighted the potential benefits of three STS applications during the middle reproductive stage for cannabis breeding.

Conservation and Divergence of PEPC Gene Family in Different Ploidy Bamboos.

Phosphoenolpyruvate carboxylase (PEPC), as a necessary enzyme for higher plants to participate in photosynthesis, plays a key role in photosynthetic carbon metabolism and the stress response. However, the molecular biology of the PEPC family of Bambusoideae has been poorly studied, and the function of its members in the growth and development of Bambusoideae is still unclear. Here, we identified a total of 62 PEPC family members in bamboo. All the PEPC genes in the bamboo subfamily were divided into twelve groups, each group typically containing significantly fewer PEPC members in Olyra latifolia than in Phyllostachys edulis, Dendrocalamus latiflorus and Dendrocalamus brandisii. The results of an intraspecific and interspecies collinearity analysis showed that fragment replication and whole genome replication were the main driving forces of bamboo PEPC members. Furthermore, the Ka/Ks values of collinear genes showed that bamboo PEPC experienced purification selection. In addition, the promoter region of PEPC genes contains cis-acting elements related to light response, plant hormone response and response to stress. An analysis of the expression levels of the PEPC family in different developmental stages and tissues of bamboo shoots has shown that PhePEPC7, PhePEPC9 and PhePEPC10 were highly expressed in the leaves of non-flowering plants and culms. Furthermore, PhePEPC6 was significantly upregulated in leaves after GA treatment. Further research has shown that PhePEPC6 was mainly localized in the cell membrane. This provides a solid bioinformatics foundation for further understanding the biological functions of the bamboo PEPC family.

Multiple Localization Analysis of the Major QTL-sfw 2.2 for Controlling Single Fruit Weight Traits in Melon Based on SLAF Sequencing.

Cucumis melo is an annual dicotyledonous trailing herb. It is fruity, cool, and refreshing to eat and is widely loved by consumers worldwide. The single fruit weight is an important factor affecting the yield, and thus the income and economic benefits, of melon crops. In this study, to identify the main QTLs (quantitative trait locus) controlling the single fruit weight of melon and thereby identify candidate genes controlling this trait, specific-locus amplified fragment sequencing (SLAF) analysis was performed on the offspring of female 1244 plants crossed with male MS-5 plants. A total of 115 individual plants in the melon F2 population were analyzed to construct a genetic linkage map with a total map distance of 1383.88 cM by the group in the early stages of the project, which was divided into 12 linkage groups with a total of 10,596 SLAF markers spaced at an average genetic distance of 0.13 cM. A total of six QTLs controlling single fruit weight (sfw loci) were detected. Seven pairs of markers with polymorphisms were obtained by screening candidate intervals from the SLAF data. The primary QTL sfw2.2 was further studied in 300 F2:3 family lines grown in 2020 and 2021, respectively, a positioning sfw2.2 between the markers CY Indel 11 and CY Indel 16, between 18,568,142 and 18,704,724 on chromosome 2. This interval contained 136.58 kb and included three genes with functional annotations, MELO3C029673, MELO3C029669, and MELO3C029674. Gene expression information for different fruit development stages was obtained from 1244 and MS-5 fruits on the 15d, 25d, and 35d after pollination, and qRT-PCR (quantitative reverse transcription-PCR) indicated that the expression of the MELO3C029669 gene significantly differed between the parents during the three periods. The gene sequences between the parents of MELO3C029669 were analyzed and compared, a base mutation was found to occur in the intronic interval between the parents of the gene, from A-G. Phylogenetic evolutionary tree analysis revealed that the candidate gene MELO3C029669 is most closely related to Pisum sativum Fimbrin-5 variant 2 and most distantly related to Cucumis melo var. makuwa. Therefore, it was hypothesized that MELO3C029669 is the primary major locus controlling single fruit weight in melon. These results not only provide a theoretical basis for further studies to find genes with functions in melon single fruit weight but also lay the foundation for accelerating breakthroughs and innovations in melon breeding.

The non-flowering plants of a near-polar forest in East Gondwana, Tasmania, Australia, during the Early Eocene Climatic Optimum.

The Cenozoic Macquarie Harbour Formation (MHF) hosts one of the oldest and southernmost post-Cretaceous fossil plant assemblages in Australia. Coinciding with the Early Eocene Climatic Optimum (EECO) and predating the breakup of Australia from Antarctica, it offers critical data to study the diversity and extent of the Austral Polar Forest Biome, and the floristic divergence between Australasia and South America resulting from the Gondwana breakup. The micromorphology and macromorphology of new fossil plant compressions from the MHF were described and systematically analyzed. Previously published non-flowering plant records were reviewed and revised. Macrofossil abundance data were provided. The flora was compared with other early Paleogene assemblages from across the Southern Hemisphere. Twelve species of non-flowering plants were identified from the macrofossil record. Conifers include Araucariaceae (Araucaria macrophylla, A. readiae, A. timkarikensis sp. nov., and Araucarioides linearis), Podocarpaceae (Acmopyle glabra, Dacrycarpus mucronatus, Podocarpus paralungatikensis sp. nov., and Retrophyllum sp.), and Cupressaceae (Libocedrus microformis). Dacrycarpus linifolius was designated a junior synonym of D. mucronatus. Further components include a cycad (Bowenia johnsonii, Zamiaceae), a pteridosperm (Komlopteris cenozoicus, Umkomasiaceae), and a fern (Lygodium dinmorphyllum, Schizaeaceae). The fossil assemblage represents a mixed near-polar forest with a high diversity of conifers. The morphology and preservation of several species indicate adaptations to life at high latitudes. The coexistence of large- and small-leaved conifers implies complex, possibly open forest structures. Comparisons with contemporaneous assemblages from Argentina support a circumpolar biome during the EECO, reaching from southern Australia across Antarctica to southern South America.

Orchestration of phosphate homeostasis by the ITPK1-type inositol phosphate kinase in the liverwort Marchantia polymorpha.

Land plants have evolved sophisticated sensing mechanisms and signalling pathways to adapt to phosphate-limited environments. While molecular players contributing to these adaptations in flowering plants have been described, how non-vascular bryophytes regulate phosphate (Pi) homeostasis remained largely unknown. In this study, we present findings that both male and female plants of the liverwort Marchantia polymorpha respond to altered phosphate availability through substantial developmental changes. We show that the second messenger inositol pyrophosphates (PP-InsPs) respond more quickly to changes in cellular Pi status than the lower inositol phosphates, highlighting a functional relationship between PP-InsP and Pi homeostasis in M. polymorpha. To further corroborate the possible involvement of PP-InsP in Pi homeostasis, we characterized M. polymorpha INOSITOL (1,3,4) TRIPHOSPHATE 5/6 KINASE1 (MpITPK1) that phosphorylates InsP6 to generate InsP7 both in vitro and in vivo. Consistent with the role of PP-InsPs in Pi homeostasis, M. polymorpha lines with enhanced MpITPK1 expression leading to the accumulation of 5-InsP7 and an InsP8 isomer exhibit altered expression of phosphate starvation induced (PSI) genes and display attenuated responses to low phosphate. The characterization of MpPHO1-deficient plants with dramatically increased levels of 1,5-InsP8 further supports the role of PP-InsP in Pi homeostasis in this liverwort species. Notably, our study unveiled that MpITPK1 rescues the deregulated Pi homeostasis in Arabidopsis (Arabidopsis thaliana) ITPK1-deficient plants, suggesting that liverwort and eudicots share a functional ITPK1 homolog. In summary, our study provides insights into the regulation of Pi homeostasis by ITPK1-derived PP-InsPs in M. polymorpha.

Development and validation of sex-linked molecular markers for rapid and accurate identification of male and female Hippophae tibetana plants

Hippophae tibetana, one of the highest-altitude woody plants endemic to the Qinghai-Tibet Plateau, primarily thrives on riverbanks formed by glacial meltwater. As a dioecious species, it demonstrates significant ecological and economic value in extreme alpine environments. However, the lack of sex identification techniques outside of the flowering period severely limits research on sex ratio, differentiation, and breeding. There is an urgent need to develop effective sex-linked molecular markers that are independent of developmental stages, but current research in this area remains limited. This study developed a set of accurate sex-linked molecular markers for the rapid identification of male and female individuals of H. tibetana. Through whole-genome resequencing of 32 sexually differentiated H. tibetana samples, this study offers strong evidence supporting chromosome 2 as the sex chromosome and successfully identified key loci related to sex determination on this chromosome. Utilizing these loci, we, for the first time, developed three reliable pairs of sex-specific molecular markers, which exhibited high accuracy during validation across various geographic populations, offering an effective tool for the sex identification of H. tibetana. Additionally, this study lays the groundwork for further research into the mechanisms of sex determination and the evolution of sex chromosomes in H. tibetana.

Utilizing Visible Band Vegetation Indices from Unmanned Aerial Vehicle Images for Maize Phenotyping

Recent advancements in high-throughput phenotyping have led to the use of drones with RGB sensors for evaluating plant traits. This study explored the relationships between vegetation indices (VIs) with grain yield and morphoagronomic and physiological traits in maize genotypes. Eight maize hybrids, including those from the UENF breeding program and commercial varieties, were evaluated using a randomized block design with four replications. VIs were obtained at various stages using drones and Pix4D Mapper 4.7.5 software. Analysis revealed significant differences in morphoagronomic traits and photosynthetic capacity. At 119 days after planting (DAP), the RGB vegetation index VARI showed a significant correlation (r = 0.99) with grain yield. VARI also correlated with female flowering (r = −0.87), plant height (r = −0.79), 100-grain weight (r = −0.77), and anthocyanin concentration (r = −0.86). PCA showed a clear separation between local and commercial hybrids, explaining 46.7% of variance at 91 DAP, 52.3% at 98 DAP, 64.2% at 112 DAP, and 66.1% at 119 DAP. This study highlights the utility of VIs in maize phenotyping and genotype selection during advanced reproductive stages.

Negative and sex-specific effects of drought on flower production, resources and pollinator visitation, but not on floral scent in monoecious Cucurbita pepo.

The globally changing climatic condition is increasing the incidences of drought in several parts of the world. This is predicted and already shown to not only impact plant growth and flower development, but also plant-pollinator interactions and the pollination success of entomophilous plants. However, there is a large gap in our understanding of how drought affects the different flowers and pollen transfer among flowers in sexually polymorphic species. Here, we evaluated in monoecious Styrian oil pumpkin, and separately for female and male flowers, the responses of drought stress on flower production, petal size, nectar, floral scent and visitation by bumblebee pollinators. Drought stress adversely affected all floral traits studied, except floral scent. Although both flower sexes were adversely affected by drought stress, the effects were more severe on female flowers, with most of the female flowers even aborted before opening. The drought had negative effects on floral visitation by the pollinators, which generally preferred female flowers. Overall, our study highlights that the two flower sexes of a monoecious plant species are differently affected by drought stress and calls for further investigations to better understand the cues used by the pollinators to discriminate against male flowers and against flowers of drought-stressed plants.

Comparative Study on Silver Nanoparticle Synthesis Using Male and Female Pistacia Khinjuk Leaf Extracts: Enhanced Efficacy of Female Leaf Extracts

AbstractThis study aims to uncover the potential differences in bioactive compounds present in leaf extracts obtained from female and male individuals of Pistacia khinjuk, abundantly found in the Southeast Anatolia region of Turkey, and their roles in influencing the properties of synthesized silver nanoparticles (AgNPs). Results obtained through TEM and SEM imaging techniques determined the morphology and size of AgNPs synthesized from female (FL‐AgNPs) and male (ML‐AgNPs) leaf extracts. Additionally, FTIR spectrum analysis demonstrated the chemical composition of the FL‐AgNPs, ML‐AgNPs, and the extracts. Zeta potential and zeta sizer analyses revealed differences between nanoparticles obtained from female and male plants. The total phenolic content of leaf extracts from female plants is significantly higher than that obtained from male plants (female plants: 30.68±0.26 mg GAE/g, male plants: 24.22±0.37 mg GAE/g). Furthermore, FL‐AgNPs (43.2±2.64 mg GAE/g) exhibit higher antioxidant activity compared to ML‐AgNPs (31.7±1.16 mg GAE/g). ICP‐MS analyses indicate that FL‐AgNPs are synthesized with higher efficiency compared to ML‐AgNPs (FL‐AgNPs: 99.90±0.106 %, ML‐AgNPs: 94.99±0.079 %). Finally, the antibacterial efficacy of FL‐AgNPs and ML‐AgNPs nanoparticles was evaluated agar well diffusion method against the pathogen Escherichia coli (E.Coli) and Staphylococcus aureus (S. Aureus]

Investigating the Effects of Dark Period Light Exposure on Sex Expression In Female Cannabis sativa

Hermaphroditism in female plants is a common problem in the cannabis industry. Cannabis sativa florogenesis is dependent on photoperiod, and industry experts suspect disruptions to the photoperiod contribute to hermaphroditism. The goals of this report are to (i) determine the relationship between hermaphroditism and dark period light exposure in C. sativa, (ii) identify a causal mechanism that could explain female hermaphroditism, and (iii) recommend a course of action for indoor cultivators. A literature search suggested that hermaphroditism in C. sativacould be the result of a very low fluence response. To test this idea, 403 plants grown indoors were inspected for male flowers. The distance of each plant from the nearest grow room door—the proposed source of dark period light—was used to calculate relative dark period light intensity values for each plant. Linear regression analysis was used to assess the relationship between relative light intensity and males per plant. The average males per plant was 0.136, compared with an intercept coefficient of 0.125 (p=0.00197, R2=0.0162). Based on these results, proximity to a door does not affect hermaphroditism. Because the actual light intensities during dark periods in this study were likely too low to cause very low fluence responses, this study cannot confidently evaluate the relationship between dark period light exposure and hermaphroditism in C. sativa. Management at the study site would be advised not to spend resources addressing grow room door light leaks.

When is lethal deceptive pollination maintained? A population dynamics approach.

Not all plant-pollinator interactions are mutualistic, and in fact, deceptive pollination systems are widespread in nature. The genus Arisaema has a pollination system known as lethal deceptive pollination, in which plants not only attract pollinating insects without providing any rewards, but also trap them until they die. Many Arisaema species are endangered from various disturbances including reduction in forest habitat, modification of the forest understory owing to increasing deer abundance, and plant theft for horticultural cultivation. We aimed to theoretically investigate how lethal deceptive pollination can be maintained from a demographic perspective and how plant and pollinator populations respond to different types of disturbance. We developed and analysed a mathematical model to describe the population dynamics of a deceptive plant species and its victim pollinator. Calibrating the model based on empirical data, we assessed the conditions under which plants and pollinators could coexist, while manipulating relevant key parameters. The model exhibited qualitatively distinct behaviours depending on certain parameters. The plant becomes extinct when it has a low capability for vegetative reproduction and slow transition from male to female, and plant-insect co-extinction occurs especially when the plant is highly attractive to male insects. Increasing deer abundance has both positive and negative effects because of removal of other competitive plants and diminishing pollinators, respectively. Theft for horticultural cultivation can readily threaten plants whether male or female plants are frequently collected. The impact of forest habitat reduction may be limited compared to that of other disturbance types. Our results have emphasised that the demographic vulnerability of lethal deceptive pollination systems would differ qualitatively from that of general mutualistic pollination systems. It is therefore important to consider the demographics of both victim pollinators and deceptive plants to estimate how endangered Arisaema populations respond to various disturbances.

Sexual dimorphism and pollination mechanism of Zanthoxylum armatum, a vulnerable medicinally important dioecious tree

Among dioecious species, the differential strategy of resource allocation between male and female plants is depicted in their life-history traits and reproductive features. This is classified as sexual dimorphism. The strategies of resource allocation along with the habitat of these species pose an impact on their pollination mechanism and reproductive success. Zanthoxylum armatum DC (Rutaceae) is a small tree with wide economic and medicinal value. The species is naturally distributed in tropical parts of India and other countries. Due to overexploitation of natural populations in India, the species is rapidly declining. To restore the population of the species in the wild and establish commercial plantations, detailed knowledge of its reproductive biology is essential. Thus, the present study was conducted in natural population of Z. armatum growing in the union territory of Jammu and Kashmir, India. The study revealed sex-biased allocation and sexual dimorphism both in vegetative and reproductive traits. Such traits include more height and higher number of shoots, inflorescences, and flowers in male plants than in female plants. The natural populations of Z. armatum exhibit a male-biased sex ratio, and such biasness appears to be the outcome of resource allocation strategies and other demographic characteristics. Species possibly exhibit presence of ambophilous suite, i.e., a combination of wind and insect pollination in floral features. However, pollen dispersal by wind is up to limited distance, and thus wind may or may not be effective in fruit-set.

Floral visitors, pollinators and floral rewards of the Australian dioecious arid zone shrub Pimelea microcephala subsp. microcephala

ABSTRACT Entomophilous dioecious plants may present opportunities to conserve insect populations as they often possess flowers accessible to a diversity of visitors and potential pollinators. Additionally, flowers of each sex can vary in the nutrients they provide. Two South Australian populations of the largely dioecious arid zone shrub Pimelea microcephala subsp. microcephala (Thymelaeaceae) were investigated to determine the conservation utility of the species to conserve insect populations by assessing floral visitor and pollinator diversity and the nutritional quality of pollen and nectar. Fifty-five visitors representing species in six insect orders were recorded at Baron Station, while 49 visitors from three insect orders were recorded at Clements Gap. Thirty-nine of the observed visitors were captured, of which two species of Hymenoptera, two of Diptera and one of Hemiptera were carrying pollen and thus potential pollinators. Visitation rates were higher for male than female plants at Clements Gap, but the reverse at Baron Station. Pollen from male plants had low protein content (2.5% dried weight (DW)) compared to co-flowering hermaphroditic angiosperms at the sites (5.3–14.0% DW). In contrast, floral extracts from male plants had at least 2× greater cumulative sugar concentrations than those of females at the same site, but female extracts had at least 4× higher protein content than male ones. As a food resource plant, P. microcephala subsp. microcephala may represent an important plant species for revegetation efforts that support the conservation of insect diversity in arid regions and throughout its broad range.

Insect Herbivores, Plant Sex, and Elevated Nitrogen Influence Willow Litter Decomposition and Detritivore Colonization in Early Successional Streams

Headwater streams are reliant on riparian tree leaf litterfall to fuel brown food webs. Terrestrial agents like herbivores and contaminants can alter plant growth, litter production, litter quality, and the timing of litterfall into streams, influencing aspects of the brown food web. At Mount St. Helens (USA), early successional streams are developing willow (Salix sitchensis) riparian zones. The willows are attacked by stem-boring herbivores, altering litter quality and the timing of litterfall. Within a established experimental plots, willows (male and female plants) were protected from herbivores using insecticides and provided with experimental additions of nitrogen. This enabled us to test the interacting influences of herbivores, nitrogen deposition, and willow sex on leaf litter quality, aquatic litter decomposition, and microbial and invertebrate detritivores. We found weak litter quality effects (higher N and lower C:N) for the herbivore treatment, but no effect of nitrogen deposition. Although litter decomposition rates were not strongly affected by litter treatments, detritivore communities were altered by all treatments. Nitrogen deposition resulted in decreased bacterial richness and decreased fungal diversity in-stream. Aquatic macroinvertebrate communities were influenced by the interacting effects of herbivory and nitrogen addition, with abundances highest in herbivore litter with the greatest N addition. Shredders showed the highest abundance in male, herbivore-attacked litter. The establishment of riparian willows along early successional streams and their interacting effects with herbivores and nitrogen deposition may be influencing detritivore community assembly at Mount St. Helens. More broadly, global changes like increased wet and dry N deposition and expanded ranges of key herbivores might influence tree litter decomposition in many ecosystems.

Growth and population structure of Lodoicea maldivica in natural stands in Seychelles.

We monitored leaf production in seedlings, trunkless juvenile, immature, and mature male and female plants of the dioecious palm, Lodoicea maldivica, and studied how internode length changed with trunk height. The fieldwork was conducted in closed forest on Praslin Island and degraded forest on Curieuse Island. Data on numbers of leaves produced and rates of leaf production were used to estimate plant age. On Praslin, the interval between successive leaves increased from 0.47/0.52 years in male/female plants to 4.2 years in seedlings, and on Curieuse from 0.41/0.49 to 2.3 years. Estimated leaf lifespan was 6.4-6.8 years in mature palms and much longer in seedlings and juveniles. On Praslin, internode length increased from the base of the trunk to a mean of 14 cm at leaf 21, before declining to 2.75 cm above leaf 100. Mean internode length of the smaller palms on Curieuse was 1.9 cm and varied little with height. Plants at the same development stage varied widely in age. On Praslin, median time to maturity was 77 (range: 32-209) and on Curieuse 83 (31-191) years. The tallest palms on Praslin (28.4 m trunk height) and Curieuse (8 m) were estimated at 442 and 232 years old, respectively. The ageing method was used to interpret height data of different populations. All showed a marked decline in regeneration in the 19th or early 20th centuries, probably caused by fires. We conclude that slow growth makes this species very vulnerable to disturbance, especially from fire.

A new species of Porophyllum (Asteraceae: Tageteae) from the northwest of Argentina, and the first record of female plants of Porophyllum cabrerae

Porophyllum riparium, a new species of the genus Porophyllum, is described. Morphological details, illustration, geographical distribution, and photographs in its natural habitat are provided. This new species occurs in the northwest region of Argentina, in Salta, Jujuy and Tucumán Provinces, in the Yungas biogeographical province. It is usually found on rocky and sandy soils, as well as along riverbanks. Porophyllum riparium is characterized by being an annual or short-lived perennial, glaucous, odoriferous, monoecious herb, 15–80(–130) cm tall, with sessile or attenuate into a pseudopetiole, linear-elliptic leaves with submarginal and subapical semi-pellucid oil cavities, lemon-colored infundibuliform corollas and exserted brownish anthers. Additionally, female plants of Porophyllum cabrerae were documented for the first time, photographs and descriptions of their female florets are included. Also, a key to identify northwestern species of Porophyllum is provided.

Chromosome-level genome assembly of Hippophae rhamnoides variety

Fructus hippophae (Hippophae rhamnoides spp. mongolica×Hippophae rhamnoides sinensis), a hybrid variety of sea buckthorn that Hippophae rhamnoides spp. mongolica serves as the female parent and Hippophae rhamnoidessinensis serves as the male parent, is a traditional plant with great potentials of economic and medical values. Herein, we gained a chromosome-level genome of Fructus hippophae about 918.59 Mb, with the scaffolds N50 reaching 83.65 Mb. Then, we anchored 440 contigs with 97.17% of the total genome sequences onto 12 pseudochromosomes. Next, de-novo, homology and transcriptome assembly strategies were adopted for gene structure prediction. This predicted 36475 protein-coding genes, of which 36226 genes could be functionally annotated. Simultaneously, various strategies were used for quality assessment, both the complete BUSCO value (98.80%) and the mapping rate indicated the high assembly quality. Repetitive elements, which occupied 63.68% of the genome, and 1483600 bp of non-coding RNA were annotated. Here, we provide genomic information on female plants of a popular variety, which can provide data for pan-genomic construction of sea buckthorn and for the resolution of the mechanism of sex differentiation.

Tolypella mongolica (Charophyceae, Characeae): A new dioecious charophyte species from the center of Eurasia and implications for charophyte taxonomy, including the validation of T. porteri and the new combination for T. jwalae

A new dioecious species of Tolypella, T. mongolica sp. nov. from the section Tolypella, was described using an integrative taxonomy. It was found in three distant localities – shallows of a brackish small lake and a channel in the midland steppe in Mongolia and the Altai Mountains, and a small brackish water body in the dry steppe in Southeast Europe. It differs from other species in rbcL and ITS sequences and in distinct complex ornamentation of the oospore surface, varying from sparsely coarsely tuberculate to having the appearance of an aerial view of mountain landscape with acute to mostly sharp edges of elements at probably the ripest stage. Wide intrapopulation variability of expression of this trait, only partly explainable by oospore ripening stage, was found and illustrated for two populations, indicating previous underestimation of this phenomenon in taxonomic research. T. mongolica is richly fertile and appears to be ephemeral as most species of this genus. Only female plants were found in all localities. The absence of male plants could be referred to either their earlier development during the growing season or, less likely, parthenogenesis in this species. The description of the new species suggests taxonomic changes for two dioecious species of charophytes. Tolypella porteri stat. et comb. nov. was validated here. T. jwalae was recognized as a species of Nitella, N. jwalae comb. nov.

Monographs on invasive plants in Europe N°8: Cortaderia selloana (Schult. & Schult. f.) Asch. & Graebn

ABSTRACT Cortaderia selloana (Schult. & Schult. f.) Asch. & Graebn. (Pampas grass) is a perennial grass native to temperate and subtropical regions of South America. The species was introduced to western Europe for ornamental purposes during the nineteenth century, where it has become naturalized in anthropogenic and natural habitats, especially in sandy, open, and disturbed areas. Female plants of C. selloana produce thousands of seeds that are dispersed over long distances by wind and germinate readily. Its invasive success is also attributed to its ability to adapt and tolerate a wide range of environmental conditions, such as high salinity levels, long droughts, and soil chemical pollution. Cortaderia selloana usually invades human-disturbed habitats where it encounters little competition with other plants and high resource availability. However, the species can invade natural habitats, especially those with high light availability, causing biodiversity loss and changes in ecosystem functioning (e.g. alteration of succession and nutrient dynamics). The species may cause negative socio-economic impacts by reducing productivity of tree plantations, causing respiratory allergies, and decreasing the recreational value of invaded areas. Control costs are high due to the extensive root system that C. selloana develops and the high resprouting ability following physical damage. Although herbicides are effective control measures, their use is not allowed or is undesirable in all situations where the plant occurs (e.g. near riverbanks, natural protected sites). No biological control agents have been released on C. selloana to date, but the planthopper Sacchasydne subandina and the gall midge Spanolepis selloanae are promising targets.