Entire Margin Research Articles

Optimal Intraoperative Assessment of Gastric Margins.

Intraoperative pathology consultation (IOC) to assess margins is frequently requested during surgery of the stomach and gastroesophageal junction. We studied 110 consecutive patients undergoing gastrectomy with IOC margin assessment. Gastric margins at IOC utilized the most blocks but were least often positive. In 64% of patients, the entire gastric margin was examined using average six blocks; representative sections were examined in 25% of patients using two blocks. There was no difference in patient outcome between those who had entire vs representative sections of margin examined. Gross variables showing strongest associations with positive margins were tumor size and tumor distance to margin. Tumors sized greater than 2.3 cm had significantly increased risk of positive margin, and tumor distance greater than 4.5 cm to margin was associated with negative margins. We conclude representative sections of the closest gastric margin are sufficient to ensure R0 resection in the majority of cases.

Morpho-anatomical characters of Limonium brasiliense leaves

Limonium brasiliense (Boiss.) Kuntze, Plumbaginaceae, is a coastal herb of the Southern Brazilian states and Rio de Janeiro State. In folk medicine, it is used in the treatment of female genitourinary tract infections and menstrual cycle irregularities. The aim of this study was to describe morpho-anatomical characters with details on venation pattern of L. brasiliense leaves, collected on the coast of Rio Grande do Sul State, in Southern Brazil. Leaf samples fixed in FAA50 (5% formaldehyde, 5% acetic acid and 90% ethanol: water mixture 50:50 v/v) and 1% glutaraldehyde and preserved in 70% ethanol, were histologically sectioned and analyzed by light and scanning electron microscopy. The L. brasiliense leaves were simple, entire, incomplete, oboval-lanceolate, venation penninervous and showed rosulated phyllotaxy, entire and revolute margin, with apex rounded to slightly retuse, base attenuate and venation pattern brochidodromous. On microscopic analysis, these leaves showed a thick and striated cuticle, salt glands, isobilateral mesophyll thicker in the apical region of the leaf blade, abundant aerenchyma in the petiole and main vein, collateral vascular bundles surrounded by fiber-sclereids, lipid substances in the cuticle and polyphenols in phloem cells.

Microsorum × tohieaense (Polypodiaceae), a New Hybrid Fern from French Polynesia, with Implications for the Taxonomy of Microsorum

A new hybrid microsoroid fern, Microsorum × tohieaense (Microsorum commutatum × Microsorum membranifolium) from Moorea, French Polynesia is described based on morphology and molecular phylogenetic analysis. Microsorum × tohieaense can be distinguished from other French Polynesian Microsorum by the combination of sori that are distributed more or less in a single line between the costae and margins, apical pinna wider than lateral pinnae, and round rhizome scales with entire margins. Genetic evidence is also presented for the first time supporting the hybrid origin of Microsorum × maximum (Microsorum grossum × Microsorum punctatum), and possibly indicating a hybrid origin for the Hawaiian endemic Microsorum spectrum. The implications of hybridization for the taxonomy of microsoroid ferns are discussed, and a key to the microsoroid ferns of the Society Islands is provided.

Cyperus conglomeratus (Cyperaceae) a halophyte from Gujarat: Physicochemical, Phytochemical and Pharmacognostic studies

The aim of the present work was evaluation of physicochemical, phytochemical and pharmacognostic parameters of Cyperus conglomeratus an halophyte from Gujarat. The plant belonging to the family Cyperaceae commonly known as Sedge family. The leaf and stem was evaluated macroscopically and microscopically. Preliminary qualitative phytochemical analysis, physicochemical analysis which included loss on drying, ash values and extractive values and fluroscence analysis were done in accordance with WHO guidelines for identification and standardization of C. conglomerates. The morphological studies exhibited the organoleptic and surface characteristics of whole plant like the leaf was simple, alternate, elongated lanceolate, entire margin, acute apex, parallel veination. The microscopic and powder microscopic study showed the presence of various characteristics like parenchyma cells, spiral vessels, annular vessels, parallel venation, gramineous stomata, conjoint collateral vascular bundle, etc. The phytochemical analysis revealed the plant to be rich in steroids and triterpenes. The extractive value was maximum in methanol solvent indicating presence of more polar compounds. The fluorescence analysis under visible light & under UV light by treatment with different chemical reagents showed characteristic colour changes. The standards laid down will be helpful to ensure the efficacy, safety and purity of medicinal halophytic plant C. conglomerates. The parameters established in this study are useful for the preparation of a monograph of this plant.

Late Miocene occurrence of monogeneric family Oleandraceae from southwest China and its implications on evolution of eupolypods I

Yunnan in SW China is a world renowned hotspot for diverse species of vascular plants such as ferns. However, fossil records of the Cenozoic ferns there are insufficient to clarify their phylogeny and historical biogeography from a geological perspective. Among these derived ferns, the monogeneric family Oleandraceae, with a pantropic distribution, is natural and distinctive; however, its origin and evolution remains unknown because of the absence of fossil records. In this study, we identified a new fossil species belonging to the genus Oleandra cav. (Oleandraceae s. s.) from the upper Miocene of Yunnan, China based on a detailed comparison of morphologically similar genera and within this genus. Oleandra bangmaii sp. n. is characterised by a simple fertile frond with an entire cartilaginous margin. Moreover, the venation system in this genus is unique and comprises a prominent midrib along with parallel, closely-spaced secondary free veins. The sori are dorsally borne, with round kidney-shaped indusia. It represents the first fossil occurrence of the genus Oleandra (Oleandraceae) within its extant distribution, suggesting that its fossil history has persisted for at least 10 Ma in Asia. Our finding, together with other existing evidence, suggests that the crown of eupolypods I (the node including families Oleandraceae, Davalliaceae and Polypodiaceae) has diversified and that the climate and vegetation of Yunnan have remained relatively stable since the late Miocene.

Revisiting the Paleoproterozoic Baraboo interval in southern Wisconsin: Evidence for syn-depositional tectonism along the south-central margin of Laurentia

The Statherian Baraboo Quartzite (1710–1650 Ma) is present in the Baraboo Ranges, Wisconsin, USA. It is one of several isolated quartzites outcropping across the southern Lake Superior region. Collectively, these quartzites are known as Baraboo interval quartzites, and they record a history of basin development followed by regional deformation along the south-central Laurentian margin. Baraboo interval stratigraphy above the Baraboo Quartzite in the Baraboo Ranges is unresolved, limiting understanding of the style and history of basin formation, sedimentation, and deformation, as well as correlation between regional quartzites.New Precambrian geologic mapping within the core of the Baraboo syncline, Baraboo Ranges, WI, confirms early interpretations of local stratigraphy. The Baraboo interval section includes two upward-fining sequences separated by an angular unconformity. The lower sequence comprises the Baraboo Quartzite, Seeley Slate, and Freedom Formation. The upper sequence comprises the Dake Quartzite and Rowley Creek Slate. The depositional age of the upper sequence is poorly constrained, but could be nearly 200 million years younger than the underlying units. U-Pb detrital zircon ages for the lower conglomeratic Baraboo Quartzite and the Dake Quartzite are dominated by nearby basement ages between 1800 and 1750 Ma and 1900–1835 Ma, suggesting a restricted drainage system tapping proximal basement sources. Subsidence modeling of the lower sequence demonstrates at least 1.28 km of subsidence is required to generate the accommodation necessary to deposit the Baraboo Quartzite, Seeley Slate and Freedom Formation. These results support a model where deposition of the lower sequence between ca. 1710–1650 Ma occurred along a tectonically active plate margin. The lack of coeval magmatism in the Baraboo interval suggests deposition did not occur in a convergent, arc setting. However, coeval orthoquartzite deposition in Colorado, Arizona, and New Mexico along the southwestern margin of Laurentia (1700–1650 Ma) occurred synchronous with arc volcanism, requiring a component of plate margin convergence to the southwest. To reconcile these differences, a model where the entire southern margin of Laurentia between 1710 and 1650 Ma was dominated by strike-slip motion is favored, varying from highly oblique convergence in the southwest to dominantly strike-slip motion in the southern Lake Superior region.

Exploratory Study of Archaebacteria and their Habitat in Underground, Opencast Coal Mines and Coal Mine Fire Areas of Dhanbad

ABSTRACT Coal contains abundant microbial genera which include archaebacteria. The study of archaea kingdom in coal mines is a significant tool for knowing the relationship between coal and archaebacteria, the major role in geochemical cycle and application for further coal bio–beneficiation. The present study related to exploration of archaebacteria and their habitat in coal mining area of Dhanbad with reference to their ecology and nutrient availability that have evolve to grow under extreme conditions. Total six different sites such as two underground coal mines (Sudamdih shaft and Chasnalla underground mine), two opencast coal mines (Chandan project and Bhowra abandoned mine), Jharia mine fire and Sudamdih coal washery of Dhanbad was selected. Seven gram negative obligate anaerobic bacteria were isolated from the selected sites. The isolated species were rod and cocci shaped and the colony was round, smooth, off white in colour and with entire margin and little are cluster of cocci in shape. The isolated species were identified as Methanococcus spp, Methanobacterium spp and Methanosarcina spp. Apart from that two thermoacidophilic sulfur oxidizing bacteria Sulfolobus spp was also isolated from Jharia Coal Mine Fire. The physicochemical and biological characterization of the habitat was also studied for the entire selected area.

Bacillus alkalilacus sp. nov., isolated from a sediment sample from a lake in India.

An aerobic, endospore-forming, haloalkali-tolerant, Gram-stain-positive, motile, rod-shaped bacterium, designated strain AK73T, was isolated from a sediment sample collected from Sambhar lake, Jaipur, Rajasthan, India. Colonies were circular, 1-2 mm in diameter, glossy, smooth, yellowish and convex with an entire margin after 48 h growth on marine agar at pH 9 and 37 °C. Growth occurred at 15-42 °C, 0-10 % (w/v) NaCl and at a pH range of 7-12. Strain AK73T was positive for catalase and arginine dihydrolase 2 activities, hydrolysis of Tweens 20, 40 and 80, and negative for esculinase, caseinase, gelatinase, β-galactosidase, lipase (Tween 60) and urease activities. The fatty acids were dominated by branched iso-, anteiso-, saturated fatty acids with a high abundance of iso-C15 : 0, anteiso-C15 : 0, C16 : 0 and anteiso-C17 : 0; MK-7 was the major menaquinone. The cell-wall peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid, four unidentified phospholipids and three unidentified lipids. The DNA G+C content of strain AK73T was 54 mol%. Analysis based on comparative 16S rRNA gene sequence analysis indicated that Bacillus alcalophilus was the nearest phylogenetic neighbour, with a pair-wise sequence similarity of 96.0 %. Phylogenetic analysis showed that strain AK73T formed a separate lineage but was loosely associated with a peripheral cluster of organisms that contained Bacillus gibsonii, Bacillus murimartini and Bacillus plakortidis with similarity values of 93.6, 93.5 and 93.4 %, respectively. Based on its phenotypic characteristics and on phylogenetic inference, strain AK73T represents a novel species of the genus Bacillus, for which the name Bacillus alkalilacus sp. nov. is proposed. The type strain is AK73T (=JCM 32184T=MTCC 12637T=KCTC 33880T).

Intraprocedural Ablation Margin Assessment by Using Ammonia Perfusion PET during FDG PET/CT–guided Liver Tumor Ablation: A Pilot Study

Purpose To prospectively determine whether nitrogen 13 (13N) ammonia perfusion positron emission tomography (PET) during fluorine 18 fluorodeoxyglucose (FDG) PET/computed tomography (CT)-guided liver tumor ablation can be used to intraprocedurally assess ablation margins. Materials and Methods Eight patients (five women and three men; age range, 36-74 years; mean age, 57 years) were enrolled in this pilot study and underwent FDG PET/CT-guided microwave ablation of 11 FDG-avid liver metastases (mean diameter, 22 mm; range, 11-34 mm). All procedures were performed between March 2014 and December 2016. Complete ablation margin visibility and minimum ablation margin thickness were assessed by using intraprocedural 13N-ammonia perfusion PET compared with 24-hour postprocedural MR imaging by two independent blinded radiologists. Local tumor progression for each ablated tumor was assessed at follow-up imaging for 3-38 months (median, 17.6 months). Descriptive analysis was performed. Results Eleven of 11 (100%) ablation margins were fully assessable by using intraprocedural perfusion PET by both readers; six of eleven (55%) margins were fully assessable by both readers at postprocedural 24-hour MR imaging. By using perfusion PET, one tumor that had been judged by both readers to have a minimum margin of 0 mm progressed locally. No tumors judged to have a minimum margin greater than 0 mm at perfusion PET progressed locally. Conclusion 13N-ammonia perfusion PET during FDG PET/CT-guided liver tumor ablations can potentially be used to intraprocedurally assess the entire ablation margin, including the minimum margin. © RSNA, 2018.

Food preference and ecotoxicological tests with millipedes in litter contaminated with mercury

Worldwide, various guidelines and directives for human health and the environment aim to reduce anthropogenic mercury (Hg) emission. Forest ecosystems are natural sinks of this element, transferring it from the atmosphere to litter and soil. Millipedes play an important role in litter/soil and may be negatively affected by contamination. As a pioneering contribution to ecotoxicological test guidelines with millipedes in litter, the present study evaluated food preference of millipedes and mercury toxicity, to prevent interference of food types in toxicity responses. Four food preference tests were performed with Trigoniulus corallinus and Rhinocricus padbergi in relation to leaf morphology, leaf fragmentation level and palatability/nutritional quality. Ecotoxicological effects on these animals were evaluated with increasing concentrations of HgCl2 spiked in litter. In both species, Hg concentrations were measured in repugnatorial glands, casts, exoskeleton and gut. In 28day trials, high bioaccumulation factors (BAF) of Hg were found in gut (= 56), exoskeleton (= 49) and casts (= 39) of R. padbergi. BAFs in the gut, exoskeleton and casts of T. corallinus were lower: 52, 45 and 32, respectively. Mortality tests indicated higher sensitivity of T. corallinus to Hg, compared with R. padbergi. Regarding leaf morphology, lanceolate, linear, obovate and ovate leaf shapes and entire margin were preferred by both species. Although higher biomass gain for both species was observed by ingestion of smaller fragmentation stages, T. corallinus preferred more fragmented leaves while R. padbergi consumed more leaves with lower fragmentation level. Both species preferred and grew better in cellulose-rich litter with lower lignin content corresponding to the mixed litter, over single species leaves of Myrceugenia scutellata and Inga edulis. Therefore, future ecological tests with millipedes should consider the use of entire leaves with less irregular shapes, and higher cellulose and lower lignin contents, to provide ideal conditions for millipede growth and activity.

Evaluation of bone resection margins of segmental mandibulectomy for oral squamous cell carcinoma

Resection margins are frequently studied in patients with oral squamous cell carcinoma and are accepted as a constant prognostic factor. While most evidence is based on soft tissue margins, reported data for bone resection margins are scarce. The aim of this retrospective study was to evaluate and determine the utility of surgical margins in bone resections for oral cavity squamous cell carcinoma (OCSCC). The status of bone resection margins and their impact on survival was investigated in patients who had undergone segmental mandibulectomy for OCSCC. Medical records were retrieved for the years 2000–2012; 127 patients were identified and included in the study. Tumour-positive bone resection margins were found in 21% of the patients. The 5-year overall survival was significantly lower in this group (P<0.005). Therefore, there is a need for intraoperative feedback on the status of bone resection margins to enable immediate additional resection where necessary. Although the lack of intraoperative methods for the evaluation of bone tissue has been addressed by many authors, there is still no reliable method for widespread use. Future research should focus on an objective, accurate, and rapid method of intraoperative assessment for the entire bone resection margin to optimize patient outcomes.

Begonia adamsensis (sect. Baryandra, Begoniaceae), a new species from Luzon Island, the Philippines

Begonia adamsensis from the northern part of Luzon Island is described as a new species endemic to the Philippines. This is the latest addition to the Begonia sect. Baryandra, making the total of Philippine begonias in this section to 56 species. It resembles Begonia hernandioides because its leaves are peltate, with a broad base, acuminate tip, nearly entire margin, and a glabrous peduncle; however, it differs significantly from B. hernandioides because of its broadly ovate red stipule, pubescent petiole, elliptic peltate leaf, pubescent abaxial lamina, and 4 perianth segments in the carpellate flower. Only about 200 individuals were found in a 100-m area that is being developed as a tourist spot in the locality, hence Begonia adamsensis is hereby proposed as critically endangered.

Bacillus lacus sp. nov., isolated from a water sample of a salt lake in India.

A strictly aerobic, alkaliphilic, Gram-stain-positive, motile, rod-shaped bacterium, designated strain AK74T, was isolated from a water sample collected from Sambhar salt lake, Rajasthan, India. Colonies were circular, 1.2 mm in diameter, shiny, smooth, whitish and convex with an entire margin after 48 h growth at 37 °C with pH 9.0. Growth occurred at 25-42 °C, 0-4 % (w/v) NaCl and at a pH of 7-12. Strain AK74T was positive for aesculinase, caseinase, lipase activities and negative for oxidase, catalase, amylase, cellulase, DNase, gelatinase and urease activities. The fatty acids were dominated by branched iso-, anteiso- and saturated fatty acids with a high abundance of iso-C15 : 0, anteiso-C15 : 0, C16 : 0 and C16 : 1 and the cell-wall peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The DNA G+C content of strain AK74T was 51.6 mol%. A blast sequence similarity search based on 16S rRNA gene sequences indicated that Bacillus niabensis, Bacillus idriensisand Bacillus halosaccharovorans were the nearest phylogenetic neighbours, with a pair-wise sequence similarities of 96.6, 96.6 and 96.5%, respectively. Phylogenetic analysis showed that strain AK74T clustered with Bacillus mangrove and together clustered with Bacillus idriensisand Bacillus indicus. Based on its phenotypic characteristics and on phylogenetic inference, strain AK74T represents a novel species of the genus Bacillus, for which the name Bacilluslacus sp. nov. is proposed. The type strain is AK74T (=MTCC 12638T=KCTC 33946T=JCM 32185T).

The giant Mauritanian cold-water coral mound province: Oxygen control on coral mound formation

The largest coherent cold-water coral (CWC) mound province in the Atlantic Ocean exists along the Mauritanian margin, where up to 100 m high mounds extend over a distance of ∼400 km, arranged in two slope-parallel chains in 400–550 m water depth. Additionally, CWCs are present in the numerous submarine canyons with isolated coral mounds being developed on some canyon flanks. Seventy-seven Uranium-series coral ages were assessed to elucidate the timing of CWC colonisation and coral mound development along the Mauritanian margin for the last ∼120,000 years. Our results show that CWCs were present on the mounds during the Last Interglacial, though in low numbers corresponding to coral mound aggradation rates of 16 cm kyr−1. Most prolific periods for CWC growth are identified for the last glacial and deglaciation, resulting in enhanced mound aggradation (>1000 cm kyr−1), before mound formation stagnated along the entire margin with the onset of the Holocene. Until today, the Mauritanian mounds are in a dormant state with only scarce CWC growth. In the canyons, live CWCs are abundant since the Late Holocene at least. Thus, the canyons may serve as a refuge to CWCs potentially enabling the observed modest re-colonisation pulse on the mounds along the open slope. The timing and rate of the pre-Holocene coral mound aggradation, and the cessation of mound formation varied between the individual mounds, which was likely the consequence of vertical/lateral changes in water mass structure that placed the mounds near or out of oxygen-depleted waters, respectively.

Molecular Phylogeny and Dating of Forsythieae (Oleaceae) Provide Insight into the Miocene History of Eurasian Temperate Shrubs.

Tribe Forsythieae (Oleaceae), containing two genera (Abeliophyllum and Forsythia) and 13 species, is economically important plants used as ornamentals and in traditional medicine. This tribe species occur primarily in mountainous regions of Eurasia with the highest species diversity in East Asia. Here, we examine 11 complete chloroplast genome and nuclear cycloidea2 (cyc2) DNA sequences of 10 Forsythia species and Abeliophyllum distichum using Illumina platform to provide the phylogeny and biogeographic history of the tribe. The chloroplast genomes of the 11 Forsythieae species are highly conserved, except for a deletion of about 400 bp in the accD–psaI region detected only in Abeliophyllum. Within Forsythieae species, analysis of repetitive sequences revealed a total of 51 repeats comprising 26 forward repeats, 22 palindromic repeats, and 3 reverse repeats. Of those, 19 repeats were common and 32 were unique to one or more Forsythieae species. Our phylogenetic analyses supported the monophyly of Forsythia and its sister group is Abeliophyllum using the concatenated dataset of 78 chloroplast genes. Within Forsythia, Forsythia likiangensis and F. giraldiana were basal lineages followed by F. europaea; the three species are characterized by minutely serrate or entire leaf margins. The remaining species, which are distributed in East Asia, formed two major clades. One clade included F. ovata, F. velutina, and F. japonica; they are morphologically supported by broadly ovate leaves. Another clade of F. suspensa, F. saxatilis, F. viridissima, and F. koreana characterized by lanceolate leaves (except F. suspensa which have broad ovate leaves). Although cyc2 phylogeny is largely congruent to chloroplast genome phylogeny, we find the discordance between two phylogenies in the position of F. ovata suggesting that introgression of the chloroplast genome from one species into the nuclear background of another by interspecific hybridization in East Asian Forsythia species. Molecular dating and biogeographic reconstructions suggest an origin of the Forsythieae species in East China in the Miocene. Distribution patterns in Forsythia indicated that the species were radially differentiated from East China, and the speciation of the European F. europaea was the result of both vicariance and dispersal in the late Miocene to Pliocene.

Detecting tumour-positive resection margins after oral cancer surgery by spraying a fluorescent tracer activated by gamma-glutamyltranspeptidase

ObjectivesTumour-positive resection margins are a major problem during oral cancer surgery. gGlu-HMRG is a tracer that becomes fluorescent upon activation by gamma-glutamyltranspeptidase (GGT). This study aims to investigate the combination of gGlu-HMRG and a clinical fluorescence imaging system for the detection of tumour-positive resection margins. Materials and methodsThe preclinical Maestro and clinical Artemis imaging systems were compared in vitro and ex vivo with cultured human head and neck cancer cells (OSC19, GGT-positive; and FaDu, GGT negative) and tumour-bearing nude mice. Subsequently, frozen sections of normal and oral cancer tissues were ex vivo sprayed with gGlu-HMRG to determine the sensitivity and specificity. Finally, resection margins of patients with suspected oral cancer were ex vivo sprayed with gGlu-HMRG to detect tumour-positive resection margins. ResultsBoth systems could be used to detect gGlu-HMRG activation in vitro and ex vivo in GGT positive cancer cells. Sensitivity and specificity of gGlu-HMRG and the Artemis on frozen tissue samples was 80% and 87%, respectively. Seven patients undergoing surgery for suspected oral cancer were included. In three patients fluorescence was observed at the resection margin. Those margins were either tumour-positive or within 1 mm of tumour. The margins of the other patients were clear (≥8 mm). ConclusionThis study demonstrates the feasibility to detect tumour-positive resection margins with gGlu-HMRG and a clinical fluorescence imaging system. Applying this technique would enable intraoperative screening of the entire resection margin and allow direct re-resection in case of tumour-positivity.

A new species and two new records of Quercus (Fagaceae) from northern Vietnam.

A new species, Quercus xuanlienensis Binh, Ngoc & Bon, is described from Xuan Lien Nature Reserve, Vietnam. The new species is morphologically similar to Q. edithiae Skan, in having 8–11 pairs of secondary veins, bowl-shaped cupules and ellipsoid to cylindrical-ellipsoid and basally convex nuts. It differs in having serrulate leaf margins only at apical 1/5–1/7, almost entire margins of bracts on cupule and much longer nuts. The species is also similar to Q. fleuryi Hickel & A. Camus in having leaves glabrous on both surfaces with only an apically serrulate margin but differs in having shorter petioles, cupules enclosing 1/5 of the nut and much longer nuts. In addition, Q. disciformis Chun & Tsiang. and Q. bella Chun & Tsiang., previously known from China, are newly recorded from Ba Vi National Park, Vietnam.

Fossil leaves of Buxus (Buxaceae) from the Upper Pliocene of Yunnan, SW China

A new species, Buxus pliosinica H.S. Huang, T. Su et Z.K. Zhou n. sp. (Buxaceae) is designated based on leaf architecture and cuticular features of five compressed fossil leaves from the Upper Pliocene Sanying Formation of Yunnan, SW China. Leaves of B. pliosinica are elliptic and small, with entire margin, retuse tip, intramarginal vein, and exmedially ramified tertiary veins. The leaves are hypostomatic with anomocytic stomatal apparatuses and giant stomata. Based on comparisons of leaf morphological and cuticular features, B. sempervirens Linnaeus is considered as the nearest living relative of B. pliosinica. Morphologically, these species share similar elliptic shape and size, cuneate base, retuse tip, similar ranges of petiole length, angles of 2° vein to midvein, and distance from the intramarginal vein to the margin. In terms of cuticular features, they are similar in type of stomatal apparatus, maximum length of giant stomata and range of stomatal length, but differ in the presence of indumentum. This discovery represents the first fossil record of Buxus from the SE margin of the Tibetan Plateau, and confirms the existence of Buxus in this region by the late Pliocene. Meanwhile, the newly described fossil species contributes to our understanding of the evolution of extant Buxus.

A CASE STUDY FOR THE OCCURRENCE OF BACTERIAL LEAF SPOT OF MANGO IN PUNJAB (PAKISTAN)

A survey was conducted for bacterial black spot disease in different districts of Punjab. Maximum disease incidence was observed in Multan followed by Muzaffar Garh and Khanewal while minimum disease incidence was noted in Jhang and Lodhran district of the Punjab. Thirty symptomatic samples were collected from multiple locations and associated pathogens were isolated. Bacterial isolates were inoculated on different mango cultivars to evaluate the level of resistance. None of the cultivar was resistant against the disease although Anwar Ratool and Late Chounsa were least affected. Eighteen isolates were grown on asparagine and nutrient agar with 5% glucose medium to check their variability which depicted round, convex, creamy white and yellow pigmented colonies with entire margins. Mucoid colony growth was found when inoculated on nutrient agar with 5% glucose. Biochemical tests showed that all bacterial isolates were gram negative, salt tolerant, oxidase negative and showed negative growth while grown on asparagines medium. On the basis of these tests bacteria were found as X. campestris. Although yellow pigmented isolates were found less aggressive as compared to creamy white ones.

Notes on Colura Crenulata (Lejeuneaceae, Marchantiophyta), a New Record for Thailand, with a Sporophyte Description

Abstract Colura crenulata Grolle (Lejeuneaceae), a rare and poorly known species from Papua New Guinea, Sumatra and Borneo, was newly discovered in tropical montane forests in southern Thailand. It is characterized by its acutely mamillose lobule sac and perianth; apical crest of the lobule sac consisting of 1-5 cells; large valve composed of 18-21 hyaline margin cells and 20-29 median cells, with a single median basal cell; and nearly entire dorsal margin of the leaf. This species is described and illustrated in detail, and its diagnostic characters and a comparison with the related species are briefly treated.