Aristolochia luudamcui (Aristolochiaceae), a new species from northern Vietnam

Aristolochia luudamcui (Aristolochia subgen. Siphisia, Aristolochiaceae), a new species from Vietnam, previously misidentified as A. utriformis, is described and illustrated here. The new species is most similar to A. pseudoutriformis and A. utriformis concerning the morphology of the leaf lamina, the color of the perianth, and the shape of the limb, but A. luudamcui can be distinguished from the other two species by having a deeply 3-lobed limb and a glabrous, yellow inner surface of limb lobes. A detailed description, information on ecology, phenology, distribution, usage, a provisional assessment of the conservation status of the new species, and a comparison with morphologically similar species are provided as well.

LFR Physically and Genetically Interacts With SWI/SNF Component SWI3B to Regulate Leaf Blade Development in Arabidopsis

Leaves start to develop at the peripheral zone of the shoot apical meristem. Thereafter, symmetric and flattened leaf laminae are formed. These events are simultaneously regulated by auxin, transcription factors, and epigenetic regulatory factors. However, the relationships among these factors are not well known. In this study, we conducted protein-protein interaction assays to show that our previously reported Leaf and Flower Related (LFR) physically interacted with SWI3B, a component of the ATP-dependent chromatin remodeling SWI/SNF complex in Arabidopsis. The results of truncated analysis and transgenic complementation showed that the N-terminal domain (25–60 amino acids) of LFR was necessary for its interaction with SWI3B and was crucial for LFR functions in Arabidopsis leaf development. Genetic results showed that the artificial microRNA knockdown lines of SWI3B (SWI3B-amic) had a similar upward-curling leaf phenotype with that of LFR loss-of-function mutants. ChIP-qPCR assay was conducted to show that LFR and SWI3B co-targeted the promoters of YABBY1/FILAMENTOUS FLOWER (YAB1/FIL) and IAA carboxyl methyltransferase 1 (IAMT1), which were misexpressed in lfr and SWI3B-amic mutants. In addition, the association between LFR and the FIL and IAMT1 loci was partly hampered by the knockdown of SWI3B. These data suggest that LFR interacts with the chromatin-remodeling complex component, SWI3B, and influences the transcriptional expression of the important transcription factor, FIL, and the auxin metabolism enzyme, IAMT1, in flattened leaf lamina development.

Leaf Epidermis: The Ambiguous Symplastic Domain

The ability to develop secondary (post-cytokinetic) plasmodesmata (PD) is an important evolutionary advantage that helps in creating symplastic domains within the plant body. Developmental regulation of secondary PD formation is not completely understood. In flowering plants, secondary PD occur exclusively between cells from different lineages, e.g., at the L1/L2 interface within shoot apices, or between leaf epidermis (L1-derivative), and mesophyll (L2-derivative). However, the highest numbers of secondary PD occur in the minor veins of leaf between bundle sheath cells and phloem companion cells in a group of plant species designated “symplastic” phloem loaders, as opposed to “apoplastic” loaders. This poses a question of whether secondary PD formation is upregulated in general in symplastic loaders. Distribution of PD in leaves and in shoot apices of two symplastic phloem loaders, Alonsoa meridionalis and Asarina barclaiana, was compared with that in two apoplastic loaders, Solanum tuberosum (potato) and Hordeum vulgare (barley), using immunolabeling of the PD-specific proteins and transmission electron microscopy (TEM), respectively. Single-cell sampling was performed to correlate sugar allocation between leaf epidermis and mesophyll to PD abundance. Although the distribution of PD in the leaf lamina (except within the vascular tissues) and in the meristem layers was similar in all species examined, far fewer PD were found at the epidermis/epidermis and mesophyll/epidermis boundaries in apoplastic loaders compared to symplastic loaders. In the latter, the leaf epidermis accumulated sugar, suggesting sugar import from the mesophyll via PD. Thus, leaf epidermis and mesophyll might represent a single symplastic domain in Alonsoa meridionalis and Asarina barclaiana.

Adaptation and taxonomic value of leaf anatomical characteristics of selected Ipomoea L. species

Aim: To investigate the taxonomic value of leaf anatomical characteristics and to determine the anatomical features that enabled the species to adapt to different environmental conditions. Methodology: Three methods were applied for leaf anatomy observation: sectioning using a sliding microtome, leaf clearing and epidermal peels. Results: The findings showed some common anatomical characteristics shared in all species studied, such as incomplete leaf venation, the presence of trichome and schlerenchyma cells, and the presence of mucilaginous idioblast cells in the petiole and midrib. Straight-to-sinuous anticlinal cell walls, amphistomatic leaves, and three types of stomata: parasitic, anomocytic and staurocytic were on the abaxial side of leaf lamina in this study. Peltate and capitate glandular trichome, as well as simple trichome, were all present in the petiole, midrib and lamina. However, peltate glandular trichome were only found in the root of I. triloba. Druses were observed in all species, except I. batatas. Interpretation: Leaf anatomical characteristics possess taxonomic value, especially in species differentiation and identification, that can be subsequently useful in explaining plant's adaptation to their environment.

Characteristics of heteroblasty in Hladnikia pastinacifolia (Apiaceae), a rare endemic from Slovenia

Hladnikia pastinacifolia, the most prominent endemic plant species in Slovenia, is rare and protected because it is a stenoendemic and paleoendemic species restricted to area of Trnovski gozd (W Slovenia). However, this species can be found in various habitats. The disparity between the non-specific habitat preference of the species and its rarity has not been sufficiently explained. Here we focus on the functional morphological features that are most indicative for the ecology of plant species: the anatomical and morphological characteristics of leaves. Hladnikia pastinacifolia exhibits heterophylly during ontogeny (heteroblasty). We aimed to describe and compare the anatomical characteristics of three H. pastinacifolia leaf morphotypes among them and in relation to various habitats. Therefore, we compared leaf functional features that are indicative for the ecology of plant species: the thickness of the leaf lamina, the spongy and palisade parenchyma, the thickness of the upper and lower epidermis and the number of leaf stomata in the upper and lower epidermis. These measurements were further used to calculate the ratio between the spongy and palisade parenchyma, leaf stomata index and the density of leaf stomata. We determined that the H. pastinacifolia heteroblasty belongs to the Apium-type. Results showed that the five-pinnate leaves were the most distinct type, being the thickest, with the highest numbers of stomata abaxially. When compared among habitats, leaves from the scree habitat were the thickest according to all the tissue layers studied. The indices calculated were less useful for the distinction between leaf types and habitats.

Morphometric and biochemical features of different Bunias orientalis L. genotypes in the M. M. Gryshko National Botanical Garden of the NAS of Ukraine

Purpose. Determine a number of morphometric and biochemical parameters of various genotypes of Bunias orientalis L. in the M. M. Gryshko National Botanical Garden of the NAS of Ukraine (NBG). Methods. Plant samples of B. orientalis (6 genotypes created in the NBG) were examined during the flowering stage. Determination of dry matter, ash, calcium was carried out according to Hrytsaienko et al. (2003), phosphorus according to Pochinok (1976), sugars, ascorbic acid and lipids were determined according to Krishchenko (1983), b-carotene according to Pleshkov (1985). The energy value of plants was determined using an IKA C-200 calorimeter. The obtained results were analysed statistically. Results. The height of plants varied from 140.9 (Genotype 1) to 157.5 (Genotype 5) cm, stem diameter from 11.67 (Genotype 1) to 16.1 (Genotype 6) mm, the number of internodes from 18.7 (Genotype 1) to 25.7 (Genotype 6), the number of leaves on a stem from 14.11 (Genotype 1) to 21.8 (Genotype 5), leaf lamina length from 14.2 (Genotype 1) to 23.45 (Genotype 6) cm, leaf lamina width from 6.34 (Genotype 1) to 14.5 (Genotype 4) cm, inflorescence length from 27.4 (Genotype 1) to 45.4 (Genotype 3) cm, inflorescence width from 2.32 (Genotype 1) to 4.92 (Genotype 3) cm, and the number of stems from 2.55 (Genotype 2) to 5.33 (Genotype 1). The study of the content of structural and functional compounds and nutrients at the flowering stage showed that the dry matter content was in the range of 13.58–16.00%, sugars 5.07–8.86%, titratable acidity 3.28–4.25%, lipids 3.33–6.61%, ascorbic acid 382.83–693.82 mg%, b-carotene 0.94–3.48 mg%, ash 6.79–9.2%, calcium 1.00–2.44%, phosphorus 1.61–2.67% and energy value 3337.0–3498.0 cal/g. Conclusions. It was revealed that samples of various genotypes of B. orientalis are a valuable source of nutrients at the flowering stage. The biochemical composition of plants depended on the genotype and stage of growth. Results of the morphometric study showed variability of investigated parameters. The obtained data can be used to predict and evaluate the results of introduction and breeding studies with B. orientalis genotypes as promising crops in Ukraine.

Genetics of flower colour in pink flowered “Rosea” and white flowers “Alba” in periwinkle Catharanthus roseus (L) G. Don

Genetics of flower Colour in winka Catharanthus roseus (L) G. Don were in vestigate by inheritance two types (strains) of plants with different flowers colour were used in this study,pink corolla, and strong violet-purple eye color, and strong pink stem, and dark green leaf lamina (P), and White corolla, and yellow and greenish eye, and strong pink stem, and yellow and green leaf lamina (W) as parents, to determine the number of genes involved. This study was conducted at Horticulture Administration, Ministry of Agriculture, Kassala State, Sudan during for three years the period: Jan 2016 to Oct. 2020. First the two parents were covered to ensure self-pollination. Reciprocal cross has been carried out between the two inbred parents. The study showed that a single pair of genes is probably involved in flower colour and that gene for pink corolla, and strong violet-purple eye color, and strong pink stem, and dark green leaf lamina (P) is incompletely dominant over that for White corolla, and yellow and greenish eye, and strong pink stem, and yellow and green leaf lamina (W). The reciprocal crosses gave the same results indicating no role of cytoplasmic genes in the inheritance of these colors.

An In Vitro–Ex Vitro Micropropagation System for Hemp

Hyperhydricity of shoots initiated in vitro, poor shoot extension, inability of shoot cultures to maintain good growth over an extended time, and unsuccessful ex vitro rooting have limited the development of a commercial scale micropropagation system for hemp (Cannabis sativa). We present a culture initiation method that prevents shoot hyperhydricity using vented-lid vessels with 0.2-µm pores and medium containing agar at 1% (w/v). To optimize shoot multiplication in vitro, a control medium (medium A) and four treatment media (medium B, C, D, and E), with varying inorganic nutrients and vitamins were tested. Control medium A consisted of 1× Murashige and Skoog (MS) with vitamins plus 3% (w/v) sucrose, 0.5 mg·L−1 metatopolin, 0.1 mg·L−1 gibberellic acid, and 0.8% agar (w/v) at pH 5.7. The four treatment media differed from the control medium as follows: medium B, 2.5× MS with vitamins; medium C, 1× MS with vitamins plus added mesos [calcium chloride (anhydrous), magnesium sulfate (anhydrous), and potassium phosphate (monobasic) nutrients]; medium D, 1× MS with vitamins plus added vitamins; and medium E, 1× MS with vitamins plus added mesos and vitamins. Medium C and medium E produced more microcuttings than the control at 6 weeks after the initial subculture with shoot multiplication media and all other treatments at 9 and 12 weeks. Shoots grown on these two media displayed optimal extension and leaf lamina development; however, they exhibited slight chlorosis by 12 weeks after subculture with shoot multiplication media. In a separate experiment, medium E was supplemented with ammonium nitrate at 0, 500, 1000, or 1500 mg·L−1, and cultures grown with 500 mg·L−1 produced the most microcuttings and exhibited the best combination of shoot extension and leaf lamina development. We provide a method of prerooting microshoots in vitro that has resulted in 75% to 100% rooting ex vitro in rockwool. Using 10 recently micropropagated plants, ≈300 retip cuttings (cuttings taken from new shoots from recently micropropagated plants) were harvested over 10 weeks. The average weekly rooting was more than 90%. Retipping can produce nine-times as many plants in a similar amount of floor space as stem cuttings derived from traditional stock mother plants. The micropropagation/retipping method proposed can be a more efficient way to generate clonal liner plants for commercial-scale production.

Reconciling the Plant-Animal Interface: Convergence of Optimal Herbage Accumulation and Intake Rate by Sheep Grazing Tall Fescue

Aims This study evaluated the optimal herbage level from both plant and animal perspectives, through the adjustment of instantaneous herbage accumulation rate as estimed by the Gompertz curve model and short-term intake rate of sheep. Schedonorus arundinaceus (tall fescue) was used as an experimental model. Methods Weekly tall fescue herbage accumulation was measured during seven growth periods initiated on monthly intervals (October, November, and December 2015, and March, April, August and September 2016) with the initiation dates arranged in a randomized complete block design with four replicates. Total herbage mass, leaf lamina mass, pseudo-stem + sheath mass, senescent mass, and sward surface height were measured each week. Results We demonstrated that a pre-grazing sward surface height of 22.3 cm of tall fescue promoted concomitantly the maximum short-term intake rate of sheep and the instantaneous herbage accumulation rate in the spring and autumn periods. In general, the convergent point occurred after the maximum instantaneous leaf lamina accumulation rate and before the maximum instantaneous accumulation rate of pseudo-stem + sheath and senescent material. Conclusions We suggest the existence of a convergent point in which both primary and secondary production of pastoral ecosystems could be fostered, potentially reconciling the fundamental ecological dilemma of grazing systems.