Size Of Vascular Bundles Research Articles

Variations in characteristics of bamboo vascular bundles between Dendrocalamus and Bambusa

Unraveling the characteristics of bamboo vascular bundles is critical for understanding their physiology and mechanical properties. However, different bamboo species have different vascular bundles, leading to significant variations in their industrial applications. In this paper, the You Only Look Once algorithm was applied to examine the vascular bundles of several species representatives within Dendrocalamus (Dendrocalamus farinosus, Dendrocalamus asper, and Dendrocalamus latiflorus) and Bambusa (Bambusa pervariabilis, Bambusa textilis, and Bambusa arundinacea), considering their economic and ecological importance. The analysis included the classifications of vascular bundles, their dimensions, and the areas of fiber sheaths. The results showed that the vascular bundles of Dendrocalamus and Bambusa were mainly broken-waist type. Along the radial direction, both Dendrocalamus and Bambusa exhibited gradient variability in vascular bundles, suggesting a similar underlying structural pattern. Quadratic functions could be employed to represent the radial distributions of vascular bundle size and fiber sheath area. Statistically, the fiber sheath area was positively correlated with vascular bundle size (P<0.05). In addition, significant differences in vascular bundles were detected among different bamboo species, which may lead to substantial variations in their mechanical properties. In particular, Bambusa arundinacea had the highest vascular bundle length (724.57 μm) and length/width ratio (1.69), while Dendrocalamus asper had the highest vascular bundle width (552.20 μm) and fiber sheath area (0.22 mm2). Nevertheless, principal component analysis indicated substantial similarity in the vascular bundles of Dendrocalamus and Bambusa. Moreover, the interspecific variations in vascular bundles were notably more pronounced within Dendrocalamus compared to those observed within Bambusa. Overall, our study examined the variations in vascular bundles between Dendrocalamus and Bambusa, offering insights that hold significant potential for bamboo taxonomy and the design of bio-inspired materials.

Response of the functional traits of Schoenoplectus tabernaemontani to simulated warming in the Napahai wetland of northwestern Yunnan, China

The impact of climate warming on wetland ecosystems is a current focal point in ecological research. In this study, the Napahai wetland, a typical plateau wetland in northwest Yunnan Province, was selected as the study site to understand the growth and survival strategies of emergent plants in a plateau wetland under climate warming conditions. Open-top chambers (OTCs) were used to simulate warming in three treatments (i.e., control group, 2.0 ± 0.5°C, and 4.0 ± 0.5°C) in order to study the responses of the functional traits of the dominant emergent plant Schoenoplectus tabernaemontani to simulated warming. The results showed that simulated warming significantly reduced the photosynthetic carbon assimilation capacity and biomass accumulation of S. tabernaemontani, as well as its nitrogen content and vascular bundle density, while it significantly increased the vascular bundle size. The growing season accumulated temperature (AT) and the mean temperature of the hottest month (WT) were the main temperature factors influencing the functional traits of S. tabernaemontani. In summary, simulated warming significantly affected the functional traits of S. tabernaemontani, which demonstrated effective adaptation to warming conditions. As the temperature rises and the light and productivity decrease, S. tabernaemontani prioritizes the supply of limited resources to the underground part to ensure the biomass supply of the reproductive structure. This study provides a case for revealing the response patterns and ecological adaptation strategies of plateau wetland plants to climate warming.

Morphological features and anatomical structure of the leaves of Dagestan endemic species of &lt;i&gt;Allium&lt;/i&gt;

Aim. To conduct a comparative analysis and assessment of the taxon specificity of the morphological and anatomical features of the leaves of endemic species of the genus Allium in Dagestan. Material and Methods. The research materials were samples of endemic species of the genus Allium from the natural populations of mountainous Dagestan: A. daghestanicum; A. gunibicum; A. charadzeae; A. mirzojevii and A. samurense. For the analysis of morphometric features, 10 generative individuals were collected in the full flowering phase. Processing of the collected material was carried out at the Laboratory of Introduction and Genetic Resources of the Mountain Botanical Garden, Dagestan Federal Research Centre, Russian Academy of Sciences. Fixation of the material and preparation of temporary micropreparations were carried out according to the generally accepted methods of anatomical studies. Anatomical studies were carried out on leaves of medium formation from the middle part of the leaf. Morphometric parameters of tissues and cells were measured using a Levenhuk D870T optical microscope with an eyepiece micrometer. Micropreparations were photographed using a Lomo‐AT 054 optical microscope and a DCM 510 SCOP video eyepiece. Results. A grouping of species according to leaf size was carried out: large‐leaved (A. daghestanicum, A. gunibicum, A charadze section Dagestanica. Tscholok. Friesen) and small‐leaved (A. mirzojevii, A. samurense section Oreiprason F. Herm.), according to the shape of the leaf cross section: grooved with smooth edges (A. daghestanicum), grooved with ribbed edges (A. gunibicum and A charadze) and rounded ribbed (A. mirzojevii and A. samurense), according to the number and size of vascular bundles. Descriptions of the anatomical structure of the leaves and an assessment of the species specificity of the studied traits of five species of Allium were carried out. Conclusions. It was determined that some features of the morphology and anatomy of the leaves of five endemic species of the genus Allium are species‐specific or due to environmental conditions of growth in the arid conditions of Inner Mountain Dagestan.

Comparative Fruit Morphology and Anatomy of Wild Relatives of Carrot (Daucus, Apiaceae)

Fruit morphological and anatomical characteristics are essential in the taxonomy of Apiaceae. Daucus L. is one of the most important genera of the family Apiaceae, as it contains the cultivated carrot, a crop of great economic importance, and about 40 wild species that could serve as potential sources of genetic diversity for crop improvement. However, the taxonomic and phylogenetic relationships among these species have not yet been fully clarified. In this study, we comparatively investigated the fruit morphology and anatomy of 13 Daucus taxa and four closely related non-Daucus species using light and scanning electron microscopy to evaluate the taxonomic value of these characteristics. A wide range of variations was observed in the fruit morpho-anatomical characteristics across the taxa and revealed several diagnostically valuable features, thus proving to be taxonomically useful. For Daucus, the observed differences included the fruit size (2.1–8.4 mm), shape (from ellipsoid to oblong), and weight (0.079–1.349 g/100 fruits), as well as the fruit surface sculpturing and some anatomical characteristics, i.e., the presence/absence and size of vittae, the shape and size of vascular bundles, and the shape of exocarp cells. This study contributes to a better understanding of the relationships among the genus Daucus.

Nodes play a major role in cadmium (Cd) storage and redistribution in low-Cd-accumulating rice (Oryza sativa L.) cultivars

Rice cadmium (Cd) contamination is one of the critical agricultural issues. Breeding of low-Cd-accumulating cultivar is an effective approach to reduce Cd bioaccumulation in rice. To investigate the molecular mechanism underlying Cd transport in rice, the functions of nodes in Cd transport are explored. The results show that different nodes have different functions of Cd transport in the rice plant and the physiological structure of the first node under panicle (N1) determine the Cd accumulation in the brown rice. The upper nodes can redistribute the Cd transport in aboveground tissues. The expressions of Cd-efflux transporter genes (OsLCT1 and OsHMA2) located on the plasma-membrane are the main factors affecting the Cd transport form node to brown rice, which are more depended on the node functions but not the node Cd concentrations. Lower expressions of OsLCT1 and OsHMA2 in N1 result in lower Cd transport from node to brown rice. The size of vascular-bundle (VB) areas in the junctional node with the flag leaf can determine the expression of OsHMA2 and the expression of OsLCT1 positively correlated with the Cd transport ability of first node (N1). The expressions of OsVIT2 and OsABCC1 cannot allow Cd to be immobilized into the vacuoles in node. The VB structure and Cd transporter gene expression level of N1 proved that the Cd concentration of N1 can be used as an important indicator for screening low-Cd-accumulating cultivars. The major implication is that selecting or breeding cultivars with lower Cd accumulations in N1 could be an effective strategy to reduce Cd accumulation in rice grains.

Altered anatomical appraisal of mung bean (Vigna radiata (L.) Wilczek) under salinity stress

Mung bean, an important pulse crop, its growth, and development are affected by various abiotic stresses where salinity hampers yield seriously. An experiment was conducted under the hydroponic condition to observe the effect of salinity on the anatomical attributes of mung bean genotypes. The design of the experiment was randomized complete with factorial having five levels of salinities i.e. 0 (control), 6, 8, 10, 12 dSm-1. The results indicated that anatomical features of mung bean plants were affected by the application of salt. The cortex and stele radius and vascular bundle strands were reduced due to salt application. The vascular bundle size especially the length was decreased with the increased levels of salinity. Similarly, the radius of cortex was also decreased with the increased levels of salinity. The results concluded that the application of salts altered the plant's internal structures, especially the vascular bundles and leaf spongy parenchyma tissue.&#x0D; Bangladesh J. Sci. Ind. Res. 57(3), 139-148, 2022

Growth and Anatomical Adaptations in Response to Salinity Stress in Cucurbita moschata Duchesne ‘Butternut’ (Cucurbitaceae)

Pumpkin or squash is an economically important crop that is moderately sensitive to salinity but how its growth is affected by soil salinity is poorly understood. Salinity stress on physiological and anatomical traits of Cucurbita moschata ‘Butternut’ was investigated under hydroponic culture using Hoagland’s solution with various NaCl concentrations (0, 25, 50, 75, 100, and 150 mM) for four weeks. The results showed that pumpkin growth characters decreased after cultured in various NaCl concentrations. Leaf number, leaf width, leaf length, root number, stem height, stem diameter, green intensity in terms of SPAD units, chlorophyll fluorescence (Fv’/Fm’, Fv/Fm), total chlorophyll, chlorophyll a and chlorophyll b contents significantly (p &lt; 0.05) decreased after culture in various NaCl concentrations. Salinity stress impacted fiber layer thickness, vascular bundle size and vessel diameter of treated plants but did not affect cuticle thickness. Physiological and anatomical traits significantly correlated with salinity gradients, except for chlorophyll b and chlorophyll fluorescence, in both light and dark condition. Results provide significant data to improve the understanding of adaptation mechanisms of tolerant pumpkin cultivars under salinity stress condition.

OsCOMT, encoding a caffeic acid O-methyltransferase in melatonin biosynthesis, increases rice grain yield through dual regulation of leaf senescence and vascular development.

SummaryMelatonin, a natural phytohormone in plants, plays multiple critical roles in plant growth and stress responses. Although melatonin biosynthesis‐related genes have been suggested to possess diverse biological functions, their roles and functional mechanisms in regulating rice grain yield remain largely unexplored. Here, we uncovered the roles of a caffeic acid O‐methyltransferase (OsCOMT) gene in mediating rice grain yield through dual regulation of leaf senescence and vascular development. In vitro and in vivo evidence revealed that OsCOMT is involved in melatonin biosynthesis. Transgenic assays suggested that OsCOMT significantly delays leaf senescence at the grain filling stage by inhibiting degradation of chlorophyll and chloroplast, which, in turn, improves photosynthesis efficiency. In addition, the number and size of vascular bundles in the culms and leaves were significantly increased in the OsCOMT‐overexpressing plants, while decreased in the knockout plants, suggesting that OsCOMT plays a positive role in vascular development of rice. Further evidence indicated that OsCOMT‐mediated vascular development might owe to the crosstalk between melatonin and cytokinin. More importantly, we found that OsCOMT is a positive regulator of grain yield, and overexpression of OsCOMT increase grain yield per plant even in a high‐yield variety background, suggesting that OsCOMT can be used as an important target for enhancing rice yield. Our findings shed novel insights into melatonin‐mediated leaf senescence and vascular development and provide a possible strategy for genetic improvement of rice grain yield.

A universal transfer-learning-based detection model for characterizing vascular bundles in Phyllostachys

A comprehensive understanding of vascular bundles is the key to elucidate the excellent intrinsic mechanical properties of bamboo. This research aims to investigate the gradient distribution of fiber volume fraction and the gradient changes in the size of vascular bundles along the radial axis in Phyllostachys. The inter-nodes of twenty-nine kinds of Phyllostachys were collected, which the cross section was sanded by sanding pads with 320 mesh and scanned with a resolution of 9600 ppi. A universal transfer-learning-based vascular bundle detection model with high precision of up to 96.97% were built, which can help to obtain the characteristics of vascular bundles quickly and accurately. The total number of vascular bundles, total fiber sheath area, the length, width and area of fiber sheath of individual vascular bundles within the entire cross-section were counted and analyzed. The results showed that these parameters had a strongly positive linear correlation with the outer circumference and wall thickness of bamboo culms, but the fiber volume fraction (25.50 ± 3.51%) and the length-to-width ratio of the vascular bundles (1.226 ± 0.091) were relatively constant. Furthermore, the cross section of bamboo were divided into multi-layer sheet along the wall thickness direction and the characteristics of vascular bundle were counted in each layer. The results showed that the fiber volume fraction decreased exponentially along the radial direction from skin to core, the length-to-width ratio of vascular bundle decreased quadratically along the radial direction from skin to core, the width of vascular bundle increased linearly along the radial direction from skin to core. The trends of the gradient change in vascular bundle’s characteristics were found highly consistent among bamboo species in Phyllostachys.

Responses of leaf hydraulic traits of Schoenoplectus tabernaemontani to increasing temperature and CO2 concentrations

BackgroundAgainst the background of a changing climate, the responses of functional traits of plateau wetland plants to increasing temperatures and CO2 concentrations need to be understood. Hydraulic traits are the key for plants to maintain their ecological functions and affect their growth and survival. However, few studies have comprehensively considered the response strategies of wetland plants' hydraulic traits to environmental changes in the context of water and matter transport, loss, and retention. According to the latest IPCC prediction results, we performed experiments under increased temperature (2 °C) and CO2 levels (850 μmol/mol) in an artificial Sealed-top Chamber (STC) to investigate the responses of the hydraulic characteristics of Schoenoplectus tabernaemontani, the dominant species in plateau wetlands in China.ResultsCompared with the CK group, net photosynthetic rate, transpiration rate, stomatal length, cuticle thickness, vascular bundle length, vascular bundle width, and vascular bundle area of S. tabernaemontani in the ET group were significantly reduced, whereas stomatal density and vein density increased significantly. Compared with the CK group, the hydraulic traits of S. tabernaemontani in the EC group were reduced considerably in stomatal length and cuticle thickness but increased dramatically in stomatal density, and there were no significant differences between other parameter values and the control group. Net photosynthetic rate was significantly positively correlated with stomatal length, cuticle thickness, and vascular bundle length, and stomatal conductance was significantly positively correlated with cuticle thickness. The transpiration rate was significantly positively correlated with cuticle thickness, epidermal cell area, vascular bundle length, vascular bundle width, and vascular bundle area. Regarding the hydraulic traits, there was a significant negative correlation between stomatal density and stomatal length, or cuticle thickness, and a significant positive correlation between the latter two. The epidermal cell area was significantly positively correlated with epidermal thickness, vascular bundle length, vascular bundle width, and vascular bundle area.ConclusionsIncreased temperature and CO2 levels are not conducive to the photosynthetic activity of S. tabernaemontani. Photosynthetic rate, stomatal density and size, vein density, epidermal structure size, and vascular bundle size play an essential role in the adaptation of this species to changes in temperature and CO2 concentration. In the process of adaptation, hydraulic traits are not isolated from each other, and there is a functional association among traits. This study provide a scientific basis for the management and protection of plateau wetlands.

Microscopic characterization of petiole anatomy of Asteraceous taxa of Western Himalaya-Pakistan.

Petiole anatomy of 15 species of family Asteraceae was examined which aimed to investigate petiolar anatomical structures for species level identification. Shandon Microtome was used for petiole histological preparations. Both qualitative and quantitative features were studied under microscope which showed significant variation in petiole, collenchyma, parenchyma shape/size, vascular bundles arrangement/size, and vessel elements quantity. Artemisia japonica Thunb., Cirsium vulgare (Savi) Ten., Myriactis nepalensis Less., Seriphidium brevifolium Ling & Y.R.Ling, Taraxacum officinale (L.) Weber ex F.H.Wigg., and Xanthium strumarium L. showed winged petioles. Maximum length and width of upper and lower epidermis was found in Tagetes erecta L. which is 23.05 ± 0.89 μm, 24.9± 1.257 μm length and 21.75 ± 1.38067 μm, 22.75 ± 0.467 μm width, respectively. Petioles of Parthenium hysterophorus L. was longest one with 9.85 ± 10.45 μm while A. japonica Thunb. showed highest number of vessel elements. Maximum size of vascular bundles was found in T. erecta L. with 5.05 ± 14.25 μm. Artemisia annua L., C. vulgare (Savi) Ten, Cyanthillium cinereum (L.) H.Rob., Helianthus annus L., M. nepalensis Less., P. hysterophorus L., Senecio chrysanthemoides DC. have trichomes while Tussilago farfara L. has highest number of vascular bundles. All species have angular collenchyma type except M. nepalensis Less., P. hysterophorus L., S. brevifolium Ling & Y.R.Ling, Tagetes minuta L., T. officinale L., S. chrysanthemoides DC., and T. farfara L. Cluster analysis implemented that distinct plant species in cluster. Petiolar anatomical structures and taxonomic key will helpful for distinguishing Asteraceous taxa at genus and species level. This taxonomic significant investigation will also provide baseline to taxonomists for other Asteraceae studies and phylogenetic research.

Crop lodging, pod fertility and yield formation in canola under varying degrees of short‐term heat stress during flowering

AbstractThere has been little research on crop lodging and yield determination in response to varying degrees of heat stress in canola. This research aimed to examine root morphology, pod fertility, seed yield and crop lodging of two canola genotypes subjected to normal temperature (23/17°C, light/dark, as CK), and three elevated temperature regimes imposed at flowering for a short term (10 days), namely CK+2 (25.0/22.0°C, light/dark), CK+4 (27.0/24.0°C) and CK+6 (29.0/26.0°C), in a controlled growth facility. Elevated temperature treatment, CK+4 and CK+6, displayed a significant adverse effect on seed yield and stem lodging. Compared to the CK, a significant yield loss of 35.6% and 48.7% in CK+4 and CK+6, respectively, was mainly due to poor pod fertility. This was evident from the smaller number of total filled pods (−21% in the CK+4 and −25% in the CK+6), low success ratio of pod developed (−25%, CK+4 and −29%, CK+6) and poor pollen viability (−36%, CK+4 and −50%, CK+6), averaged across both genotypes. Lateral root development was sensitive to the elevated temperature treatment, showing significant reductions in the lateral root morphology (8.0%–28.5%), while the taproot was relatively tolerant to the elevated temperature stress. A strong relationship between root electrical capacitance and lateral root morphology (R2 &gt; .74**) indicates that electrical measurements could be used as a non‐destructive method for evaluating root parameters under elevated temperatures. Higher risk of stem lodging (21.4% lower stem safety factor) compared to the CK was evident under severe elevated temperature stress, as ascribed from the reduced stem bending strength that was caused by the deteriorating stem mechanical properties such as decreased flexural rigidity and weakened vascular bundle size (i.e. stunted fibre cell, and thinned size of fibre wall, deteriorated secondary xylem and smaller secondary phloem). These results were further verified by the principal component analysis and structural equation model. The root lodging risk was not influenced by the elevated temperature regime, primarily due to the unaffected anchorage strength and height of the centre of gravity. This information will be useful in improving lodging resistance and alleviating the related impact of heat stress in canola.

Superior Line from Anther Culture of Dendrocalamus latiflorus Selected after Field Trial

The selection of superior lines is extremely important to improve the utilization rate and economic value of bamboo. In this research, 120 anther-regenerated bamboo lines were planted in the field, and the survival rate reached 84.2% one year after planting. During five years of observations, we continuously measured and recorded the number of shoots and the size of the new bamboo of these regenerated lines. The results showed that there were considerable differences in culm size and growth rate among the different lines. After comprehensive evaluation, we found that one of the lines (P82) had obvious advantages in culm size and growth rate compared with the others. The chromosome ploidy of line P82 and the other three lines (P38, P84, and P34) was detected. It was found that P82 was hexaploid, while the other three lines were dodecaploid. Nutritional components of the P82 shoots were further detected. The results showed that the content of soluble sugar was 1.4%, the content of free amino acid was 3.5 g·kg−1 (FW, fresh weight), and the content of protein was 14.8 g·kg−1 (FW), and there were no significant differences compared with the local wild mature bamboo. Anatomical analysis showed that the vascular bundle size of the line P82 (hexaploid) was significantly larger than that of line P38 (dodecaploid), and the length of parenchyma cells in the culm wall of line P82 was similar to that of line P38, however, the cell width of line P82 was significantly wider than that of line P38. In this study, the breeding of superior lines of regenerated bamboo plants from an anther culture was realized, which provided an example for a new method for selecting superior lines from an anther culture, and also enriched the resources of superior lines of D. latiflorus.

ANATOMICAL AND PHYSICAL CHARACTERISTICS OF Cephalostachyum mannii (Gamble) STAPLETON – AN ENDEMIC SCRAMBLING BAMBOO OF NORTHEAST INDIA

Cephalostachyum mannii is a tall, graceful scandent bamboo with solid culms. It is distributed in Arunachal Pradesh, Meghalaya, Mizoram, and Nagaland states of Northeast India. The present study was carried out to investigate radial and vertical variations in anatomical and physical properties in the culms of this bamboo species. The mature culms (3-4 years old) were selected from forests of Amkassar Amlarem village, West Jaintia Hills District, Meghalaya, India. The selected internodes of culms were radially divided into outer, middle and inner zones, and vertically bottom, middle and top positions. The vascular bundles were of Type II and well developed in middle zones of both bottom and middle positions. The number and size of vascular bundles increased from inner to outer zone and decreased from bottom to top. Vessel length and vessel diameter decreased both radially and vertically. Among fibre characteristics, fibre wall thickness increased, while fibre length, fibre diameter, and fibre lumen diameter decreased significantly in both radial and vertical directions. Among physical properties, density increased, and moisture content decreased in both radial and vertical directions. Radial shrinkage was higher than tangential shrinkage. Both radial and tangential shrinkage decreased significantly from bottom to top. The fibres were long, thick-walled and highly rigid, and the derived indices do not satisfy the requirement as a superior fibrous raw material for pulp and paper making. However, this bamboo species has the potential for making good quality handicrafts and basketry.

VARIASI DAN HUBUNGAN FENETIK AKSESI KUNYIT DI YOGYAKARTA DAN SEKITARNYA

Tujuan penelitian ini adalah menentukan variasi morfologis dan anatomis tiap aksesi Curcuma longa, serta hubungan fenetik pada spesies antar aksesi Curcuma longa. Sebanyak 13 sampel diambil di area Yogyakarta dan sekitarnya, karakter morfologis yang dibandingkan bersumber dari akar, rimpang, daun meliputi bentuk dan ukuran. Karakter anatomis diamati pada daun dan rimpang. Penentuan karakter morfologis berdasarkan Protection of Plant Varieties dan Farmers’ Rights Authority. Hubungan fenetik menggunakan perbandingan karakter morfologis dan anatomis spesies Curcuma longa yang diteliti. Hasil penelitian menunjukkan variasi morfologis Curcuma longa di Yogyakarta dan sekitarnya memiliki perbedaan tinggi tanaman, morfologis daun, serta morfologis akar dan rimpang. Variasi karakter anatomis Curcuma longa memiliki perbedaan ketebalan epidermis daun, ukuran dan densitas stomata, ketebalan berkas pengangkut, ketebalan epidermis dan hipodermis rimpang. Berdasarkan analisis fenetik Curcuma longa di Yogyakarta dan sekitarnya dapat diketahui bahwa hubungan kekerabatan fenetik berdasarkan karakter morfologis terbagi menjadi dua klaster besar dan empat subklaster, sedangkan berdasarkan karakter anatomis terbagi menjadi dua klaster dan enam subklaster.VARIATION AND PHENETIC RELATIONSHIP OF TUMERIC ACCESSIONS IN YOGYAKARTA AND SURROUNDING AREASThe purpose of this study was to determine the morphological and anatomical variations of each accession of Curcuma longa, as well as the phenetic relationship among accessions of Curcuma longa. A total of 13 samples were taken in the Yogyakarta and surrounding areas, the morphological characters compared from roots, rhizomes, leaves include shape and size. The anatomical characters were observed in the leaves and rhizomes. The determination of morphological characters based on Protection of Plant Varieties and Farmers’ Rights Authority. The phenetic relationship used a comparison of the morphological and anatomical characters of the Curcuma longa species studied. The results showed that the morphological variations of Curcuma longa in Yogyakarta and its surroundings had differences in plant height, leaf morphology, and root and rhizome morphology. Variations in anatomical characters of Curcuma longa have differences in leaf epidermis thickness, stomata size and density, carrier bundle thickness, epidermis and rhizome hypodermis thickness. Based on the phenetic analysis of Curcuma longa in Yogyakarta and its surroundings, it shows phenetic relationship based on morphological characters is divided into two large clusters and four sub-clusters, while based on anatomical characters it is divided into two clusters and six sub-clusters.

Leaf physiological and anatomical characters contribute to drought tolerance of Nusa Tenggara Timur local rice cultivars

Morpho-anatomical characters supporting the resilience of a plant under certain environmental conditions cannot be interpreted individually but thoroughly along with the physiological factors to determine the ability of plants to survive in the drought environment. In this study, we conducted a selection of Nusa Tenggara Timur (NTT) local drought-tolerant rice through the assessment of leaf anatomical characters and their correlation with physiological mechanisms. Materials used in this study were 18 local rice cultivars and 2 control cultivars. The characters of leaf includes epidermal thickness, stomatal density and size, bundle-sheath size, vascular-bundle size and bulliform-cell size were found to be negatively correlated with the changes of chlorophyll, carotenoid, and anthocyanin contents. Moreover the change in anatomical characters is positively correlated with relative water content and cell membrane stability index based on two-way ANOVA test with 95% confidence level. Although most of the cultivars undergo decreasing in all characters measured, several cultivars includes Boawae 100-Malam, Gogo Sikka, Gogo Jak, Hare Tora, Pak Mutin and Gogo Fatuhao showed high potential to be drought tolerant cultivars as found with low reduction percentage of parameters measured.

NOTES ON LEAF AND STEM ANATOMY OF Thlaspi sensu lato

In this study, anatomical characteristics of leaves and stems of 19 taxa of Thlaspi sensu lato, 9 of which are endemic to Turkey, were investigated in order to determine taxonomic relationships among the studied taxa. The anatomical characteristics of all taxa were determined and assessed using the cluster analysis and the principal component analysis. The transverse sections of the leaves and stems exhibited various diagnostic characters in terms of the pattern of epidermal cell and mesophyll layers, the number and size of vascular bundles, and the thickness of the cortex and endodermis. Important differences were detected in number, size, and index of stomata, and in epidermal cell wall structures in the adaxial and abaxial surfaces. The results showed that the compared anatomical characteristics among taxa are partially compatible with their sectional delimitation in their traditional rank in The Flora of Turkey and the East Aegean Islands. The results also point out that some taxonomic re-arrangements may be required.

Effect of stress on the leaf anatomy of sugarcane cultivars with different drought tolerance (Saccharum officinarum, Poaceae)

ABSTRACT. Introduction: Drought is an important stress factor for sugarcane production in many areas of the world. Water proportion and moisture indices are applicable information for agronomic planning to forecast water excess or deficit during the crop cycle. Objective: Leaf anatomical features of two different sugarcane Saccharum ‘UT12’ (drought susceptible cultivar) and Saccharum ‘UT13’ (drought tolerant cultivar) were compared under early drought stress situation between 30 and 90 days after planting. Methods: Forty leaf anatomical features were investigated using peeling and free hand sectioning technique. Results: Some anatomical characteristics showed response to drought stress. Saccharum ‘UT12’ demonstrated higher sensitivity toward anatomical characteristics than Saccharum ‘UT13’. A total of 23 and 15 out of the 40 anatomical characteristics showed significance in Saccharum ‘UT12’ and Saccharum ‘UT13’, respectively. Some anatomical features such as cell wall and cuticle thickness, vascular bundle size, stomatal size and density can be used as important markers for drought stress assessment in sugarcane leaf. Conclusions: This is the first report describing comparative leaf anatomy of sugarcane Saccharum ‘UT12’ and Saccharum ‘UT13’ in Thailand under drought stress. Results will provide important information to improve adaptation mechanisms of tolerant sugarcane cultivars under initial drought stress situations.

Blue and red light affects morphogenesis and 20-hydroxyecdisone content of in vitro Pfaffia glomerata accessions

The combination of different colors from light-emitting diodes (LEDs) may influence growth and production of secondary metabolites in plants. In the present study, the effect of light quality on morphophysiology and content of 20-hydroxyecdysone (20E), a phytoecdysteroid, was evaluated in accessions of an endangered medicinal species, Pfaffia glomerata, grown in vitro. Two accessions (Ac22 and Ac43) were cultured in vitro under three different ratios of red (R) and blue (B) LEDs: (i) 1R:1B, (ii) 1R:3B, and (iii) 3R:1B. An equal ratio of red and blue light (1R:1B) increased biomass accumulation, anthocyanin content, and 20E production (by 30–40%). Moreover, 1R:1B treatment increased the size of vascular bundles and vessel elements, as well as strengthened xylem lignification and thickening of the cell wall of shoots. The 1R:3B treatment induced the highest photosynthetic and electron transport rates and enhanced the activity of oxidative stress-related enzymes. Total Chl content, Chl/Car ratio, and NPQ varied more by accession type than by light source. Spectral quality affected primary metabolism differently in each accession. Specifically, in Ac22 plants, fructose content was higher under 1R:1B and 1R:3B treatments, whereas starch accumulation was higher under 1R:3B, and sucrose under 3R:1B. In Ac43 plants, sugars were not influenced by light spectral quality, but starch content was higher under 3R:1B conditions. In conclusion, red and blue LEDs enhance biomass and 20E production in P. glomerata grown in vitro.

Effect of Crude Oil Concentrations on the Vascular Bundle Size of Two Maize Varieties

The reliance of humanity on fossil fuels particularly petroleum hydrocarbons has been on the increase and had led to increased pollution of agricultural lands. This study was aimed at investigating the effect of crude oil concentrations on the vascular bundle sizes of two Zea mays varieties – Oba Super Zaria (OSZM) and SMZ 37 Kaduna commonly cultivated in the South-eastern Nigeria. The study was conducted in the green house in the Department of Biological Sciences, Faculty of Natural Sciences, Kogi State University, Ayingba, Kogi State. The experiment was setup as a 2 × 4 factorial laid out in a Completely Randomized Design replicated three times with four treatment concentrations (0-control, 15, 30 and 45 ml) of petroleum crude and two maize varieties. Highly significant effects (P &lt; 0.001) of the concentrations as well as the varieties were observed on the vascular bundles. The results showed a significant (P &lt; 0.05) decrease in vascular bundle sizes with increasing concentration, with plants exposed to 45ml crude oil concentration having the smallest vascular bundle sizes. The vascular bundle sizes of Oba super Zaria decreased significantly (p &lt; 0.05) with increasing concentrations of crude oil, while significant differences were also observed with the increasing concentrations in SMZ 37 Kaduna as compared to the control. Based on the results obtained from this investigation, OSZM appeared to be more susceptible to soils affected with crude oil.