MORPHOLOGICAL STUDIES ON NODULE BACTERIA CULTURES (RHIZOBIUM SP.)

1957 ◽  
Vol 3 (2) ◽  
pp. 399-410 ◽  
Author(s):  
Anna Lehner ◽  
W. Nowak

The evaluation of the purity and quality of nodule bacteria cultures, used for the inoculation of seeds, requires a useful morphological approach for control purposes. For that reason 23 sources of nodule bacteria were characterized with regard to their shape and form by means of living preparations. The typical stages of the nodule bacteria of various Leguminosae, appearing exclusively in the form of rods, were photomicrographed. These studies included bacteria isolated many years ago as well as those obtained in 1955. The inoculation material at hand consisted of slightly motile rods of straight and sometimes slightly bent form, the length of which differed even among nodule bacteria of the same species.In relation to the systematic classification of the Leguminosae, the nodule bacteria variations isolated from the former were united in the following 10 groups of forms:1. The forms from the Lupinus group as a morphologically homogeneous series.2. The nodule bacteria of Medicago sativa L., M. lupulina L., and Melilotus albus Med. with transitional characteristics between the individual species.3. The nodule bacteria of the Trifolium species, sometimes non-uniform, showed thick rods of variable lengths.4. The group of the nodule bacteria of Anthyllis vulneraria L., Lotus uliginosus L., and L. corniculalus L. characterized as short rods. A typical feature seems to be the development of star-shaped accumulations.5. The independent group of the nodule bacteria of Onobrychis sativa Lmk.6. The independent group of Ornithopus sativus Brot.7. The nodule bacteria of Vicia faba L. and V. sativa L. showing short and long rods with heavy mucus development.8. The nodule bacteria of Lens esculenta Moench showing short rods of varying thickness.9. The typical straight rods of Pisum sativum L. and P. arvense L.10. The long rods of Phaseolus vulgaris L. and P. nanus L. differing from those of Pisum sp. only by the slight bend of the rods and a typical development of star forms. The morphological differences we found appeared with such regularity in certain species that their occurrence was recorded in typical pictures.


2003 ◽  
Vol 43 (9) ◽  
pp. 1101 ◽  
Author(s):  
B. S. Dear ◽  
G. A. Sandral ◽  
M. B. Peoples ◽  
B. C. D. Wilson ◽  
J. N. Taylor ◽  
...  

The adaptation of 28 annual legume species to heavy clay cracking soils prone to waterlogging during winter was evaluated at 3 sites ranging in pH (CaCl2) from 4.6 to 5.4 in the wheatbelt of southern NSW. The 32 accessions and cultivars included Medicago arabica, M. polymorpha, Melilotus albus (syn. M. alba), Trigonella balansae, and 24 Trifolium species. Species identified as potentially valuable new plants for these environments included Trifolium hirtum, T. echinatum, T. glanduliferum and M. arabica for winter production, and M. albus, T. echinatum, T. glanduliferum, T. isthmocarpum, T. pauciflorum, and T. purpureum for spring production. Current cultivars of T. subterraneum subsp. brachycalycinum cv. Clare, and subsp. yanninicum, cv. Riverina, T. resupinatum cvv. Kyambro, Nitro and Prolific, and T. michelianum cvv. Bolta and Paradana, and M. polymorpha cv. Santiago, also proved well adapted. Average seed mass (size) of the legume species varied from 0.3 mg to 8.9 mg/seed with a negative curvilinear relationship between individual seed mass of a species and the number of seed set at all 3 sites (r2 = 0.59–0.89). Seed mass of a species did not influence winter productivity or seed yield. The percentage of nitrogen biologically fixed by the individual species in the first year averaged over the 3 sites varied from 30 to 75%. Species which fixed the highest proportion of their nitrogen requirement were T. subterraneum, M. arabica, T. isthmocarpum and T. resupinatum cv. Kyambro, all fixing >62% of their shoot nitrogen and having a nitrogen content >3.0%. In contrast, T. sylvaticum, T. cherleri, T. spumosum, T. stellatum and T. glomeratum performed poorly at most sites, and fixed <42% of their nitrogen requirements (averaged over 3 sites) with <2.5% nitrogen in their tissue in spring.



Author(s):  
Л.И. Герасимова-Мейгал ◽  
И.М. Сиренев

Цель исследования - изучение особенностей восприимчивости пациентов с рассеянным склерозом (РС) к холодовому воздействию с помощью функциональных тестов, характеризующих функцию терморегуляции. Как известно, РС - хроническое прогрессирующее аутоиммунное заболевание центральной нервной системы мультифакториальной природы, более часто встречающееся в регионах с холодным и влажным климатом. Нарушения терморегуляции вследствие автономной дисфункции являются характерным признаком РС, вместе с тем участию холодового фактора в развитии заболевания не придается существенного значения. Методика. Обследовано 32 пациента (17 мужчин и 15 женщин, средний возраст 29,6 ± 4,2 года) с установленным диагнозом: РС ремиттирующе-рецидивирующая форма течения (средняя продолжительность заболевания - 4,2 ± 2,7 года) и 18 практически здоровых лиц группы сравнения. Восприятие холода оценивали с помощью визуально-аналоговой шкалы. Продолжительность холод-индуцированной вазоконстрикции после локального холодового теста изучали по данным инфракрасной термометрии. Вегетативную регуляцию вазомоторных реакций оценивали по результатам анализа вызванных кожных вегетативных потенциалов (ВКВП). Результаты. На основе анализа самооценки восприятия холода у пациентов с РС показана низкая переносимость холодового фактора. При проведении локального холодового теста отмечено замедление восстановления температуры кожи кисти, что характерно для усиления холод-индуцированной вазоконстрикции. В группе пациентов с РС выявлено снижение параметров ВКВП ладоней и стоп, свидетельствующее о дефиците нейрогенного контроля терморегуляционных сосудистых реакций. Заключение. У пациентов с РС выявлены нарушения механизмов терморегуляции при действии холода, что обусловливает высокую индивидуальную восприимчивость к холоду у данной категории лиц. Сопоставление результатов анализа механизмов индивидуальной холод-индуцированной реактивности у пациентов с РС с данными эпидемиологических исследований приводит к заключению о потенциальном модулирующем влиянии холодового фактора на течение РС. The purpose of the present study was focused on the evaluation of the sensitivity to cold in multiple sclerosis (MS) patients by means of functional thermoregulatory based tests. MS is known to be a chronic autoimmune progressive disease of the central nervous system of multifactor origin that is very common in regions with cold and humid climate. Disorder of thermoregulation caused by autonomic dysfunction is a typical feature of MS, however the role of the cold in the disease development is still underestimated. Methods. Thirty two MS patients (17 males, 15 females, mean age 29,6 ± 4,2 years) with the remittent form of the disease (mean disease duration 4,2 ± 2,7 years) and 18 age-matched healthy controls volunteered to participate in this study. Susceptibility to cold was analyzed with the use of visual-analogous scale. The duration of cold-induced vasoconstriction after local cold test was estimated using by infrared thermometry. Autonomic regulation of vasomotor reactions was investigated with the help of the skin sympathetic response (SSR) analysis. Results. The analysis of self-reported perception of the cold in MS patients showed their low tolerance to cold. Slow recovery of the skin temperature of the hand in the local cold test observed in MS patients was considered as the aggravated cold-induced vasoconstriction. The decreased SSR in the hands and feet in MS patients was found that indicates the deficit of the neurogenic control of thermoregulatory vasomotor reactions. Conclusion. The results obtained demonstrate the impairment of thermoregulation under cold in MS patients that leads to higher individual susceptibility to cold of this group. Comparing of the data found in this study on the mechanisms of the individual cold-induced reactivity in MS patients with epidemiological surveys enable to conclude that cold environment has potential modulating effect of on the course of MS.



2021 ◽  
Vol 9 (4) ◽  
pp. 797
Author(s):  
Davide Mugetti ◽  
Mattia Tomasoni ◽  
Paolo Pastorino ◽  
Giuseppe Esposito ◽  
Vasco Menconi ◽  
...  

The Mycobacterium fortuitum group (MFG) consists of about 15 species of fast-growing nontuberculous mycobacteria (NTM). These globally distributed microorganisms can cause diseases in humans and animals, especially fish. The increase in the number of species belonging to MFG and the diagnostic techniques panel do not allow to clarify their real clinical significance. In this study, biomolecular techniques were adopted for species determination of 130 isolates derived from fish initially identified through biochemical tests as NTM belonging to MFG. Specifically, gene sequencing and phylogenetic analysis were used based on a fragment of the gene encoding the 65 KDa heat shock protein (hsp65). The analyzes made it possible to confirm that all the isolates belong to MFG, allowing to identify the strains at species level. Phylogenetic analysis substantially confirmed what was obtained by gene sequencing, except for six strains; this is probably due to the sequences present in NCBI database. Although the methodology used cannot represent a univocal identification system, this study has allowed us to evaluate its effectiveness as regards the species of MFG. Future studies will be necessary to apply these methods with other gene fragments and to clarify the real pathogenic significance of the individual species of this group of microorganisms.



Phytotaxa ◽  
2021 ◽  
Vol 502 (2) ◽  
pp. 191-207
Author(s):  
SHIVANI KASHYAP ◽  
CHANDAN KUMAR SAHU ◽  
ROHIT KUMAR VERMA ◽  
LAL BABU CHAUDHARY

Due to large size and enormous morphological plasticity, the taxonomy of the genus Astragalus is very complex and challenging. The identification and grouping of species chiefly based on macromorphological characters become sometimes difficult in the genus. In the present study, the micromorphology of the seeds of 30 species belonging to 14 sections of Astragalus from India has been examined applying scanning electron microscopy (SEM) along with light microscopy (LM) to evaluate their role in identification and classification. Attention was paid to colour, shape, size and surface of seeds. The overall size of the seeds ranges from 1.5–3.2 × 0.8–2.2 mm. The shape of the seeds is cordiform, deltoid, mitiform, orbicular, ovoid and reniform. The colour of seeds varies from brown to blackish-brown to black. Papillose, reticulate, ribbed, rugulate and stellate patterns were observed on the seed coat surface (spermoderm) among different species. The study reveals that the seed coat ornamentations have evolved differently among species and do not support the subgeneric and sectional divisions of the genus. However, they add an additional feature to the individual species, which may help in identification in combination with other macro-morphological features.



Author(s):  
Julie M. Fives ◽  
F. I. O'Brien

The Galway Bay area was sampled quantitatively for plankton during 1972–3. The larvae and/or post-larvae of 67 species of fish were identified from the plankton. The recorded occurrence per m3 and the percentage occurrence of the individual species is presented and discussed, and reference is made to the concurrent occurrence of various chaetognath species and copepod species. The results of previous investigations of the plankton of the Galway Bay area are mentioned.



Author(s):  
Lorena Lanthemann ◽  
Sofia van Moorsel

Duckweeds (Lemnaceae) are increasingly studied for their potential for phytoremediation of heavy-metal polluted water bodies. A prerequisite for metal removal, however, is the tolerance of the organism to the pollutant, e.g., the metal zinc (Zn). Duckweeds have been shown to differ in their tolerances to Zn, however, despite them most commonly co-occurring with other species, there is a lack of research concerning the effect of species interactions on Zn tolerance. Here we tested whether the presence of a second species influenced the growth rate of the three duckweed species Lemna minor, Lemna gibba, and Lemna turionifera. We used four different Zn concentrations in a replicated microcosm experiment under sterile conditions, either growing the species in isolation or in a 2-species mixture. The response to Zn differed between species, but all three species showed a high tolerance to Zn, with low levels of Zn even increasing the growth rates. The growth rates of the individual species were influenced by the identity of the competing species, but this was independent of the Zn concentration. Our results suggest that species interactions should be considered in future research with duckweeds and that several duckweed species have high tolerance to metal pollution, making them candidates for phytoremediation efforts.



2015 ◽  
Vol 24 (1) ◽  
pp. 34-40 ◽  
Author(s):  
B. P. Heyojoo ◽  
S. Nandy

This study aims to estimate above-ground phytomass and carbon of TROF ecosystem in part of Bijnor district in Uttar Pradesh state of India using IRS P6 LISS-IV satellite image by geo-spatial approach coupled with field sampling. Chacko’s formula was referred to compute number of samples in each TROF types and the sample plot size in each stratum was adopted from Vegetation Carbon Project (VCP) under National Carbon Project (NCP). With the help of field data consisting mainly the height and girth information, volume of each individual tree per plot was obtained using site and tree species-specific standard volumetric equations. The phytomass was calculated by multiplying volume with Biomass Expansion Factor (BEF) then with regional specific gravity of the individual species and summed up in each plot to get total phytomass per plot. The total phytomass per plot was reported to be maximum 544.00 t/ha for linear TROF followed by 121.89 t/ha for block TROF. The carbon from phytomass was obtained by multiplying the total phytomass by a conversion factor that represents the average carbon content in phytomass. Spectral modeling for phytomass with different bands and indices were established and the best fit curve (R2 = 0.552) with red band was applied to generate phytomass and carbon distribution map of the study area.Banko Janakari, Vol. 24, No. 1, pp. 34-40



Therya ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 275-281
Author(s):  
Sergio Ticul Alvarez Castañeda ◽  
Patricia Cortés-Calva

Scapanus latimanus is a species with many morphological differences among its populations.  This variation is associated with multiple taxonomic changes at the species or subspecies level.  This study incorporates genetic analyses and comparisons with previous morphological studies to propose a better understanding of the latimanus complex.  Mitochondrial markers (cytochrome b; cytochrome c oxidase subunit I; and cytochrome c oxidase subunit III) were sequenced to construct a phylogeny for the subfamily Scalopinae in North America.  Genetic distances ranged from 2.49 to 10.50 % among geographic areas.  Results identified three monophyletic clades with high bootstrap support values.  Based on our phylogenetic analysis and previous morphological analyses, we confirm S. anthonyi from San Pedro Mártir as a valid species and propose that S. occultus from southern California and northern Baja California peninsula be considered as a species



2020 ◽  
Author(s):  
Alexander A. Zhgun

A filamentous fungus (also called molds or moldy fungus) is a taxonomically diverse organism from phylum Zygomycota and Ascomycota with filamentous hyphae and has the ability to produce airborne spores or conidia. Currently, more than 70,000 molds are known, and some of them contain unique and unusual biochemical pathways. A number of products from such pathways, especially, the secondary metabolite (SM) pathways are used as important pharmaceuticals, including antibiotics, statins, and immunodepresants. Under different conditions, the individual species can produce more than 100 SM. The strain improvement programs lead to high yielding in target SM and significant reduction of spin-off products. The main tool for the strain improvement of filamentous fungi is random mutagenesis and screening. The majority of industrial overproducing SM strains were developed with the help of such technique over the past 50–70 years; the yield of the target SM increased by 100- to 1000-fold or more. Moreover, most of the strains have reached their technological limit of improvement. A new round of mutagenesis has not increased overproduction. Recently, it was shown that that the addition of exogenous polyamines may increase the production of such improved strains of filamentous fungi. The possible molecular mechanism of this phenomenon and its biotechnological applications are discussed.



Author(s):  
B.J. Wills ◽  
G.B. Douglas ◽  
J. Mckenzie ◽  
K.D. Trainor ◽  
A.G. Foote

Intermediate and pubescent wheatgrasses (Thinopyrum intermedium) are potentially useful as dryland forage grasses in New Zealand. The recent literature on their international and local use in pasture and cropping situations is reviewed. Under semi-arid conditions at Bendigo Station over a 13-year period, cv. Luna wheatgrass has spread several metres from the original drill lines and it provides very high ground cover. In terms of dryland soil resource conservation this contrasts with adjacent cocksfoot and, to a lesser extent, lucerne plots which have wide-spaced plants interspersed with litter and much bare ground. In a mixed drilling containing wheatgrass, hairy dorycnium, birdsfoot trefoil and sheep's burnet, the first two species now dominate. At Takapau, central Hawke's Bay, annual yields from intermediate and pubescent wheatgrasses produced over 80% of the yield of 10 New Zealand cultivars in spring, summer and autumn, and 65% in the winter. Of the wheatgrasses, cv. Topar intermediate wheatgrass and a pubescent wheatgrass (unnamed line) were the lowest yielding, whereas cv. Oahe and cv. Mandan produced the highest yields. Cv. Greenleaf pubescent wheatgrass had higher foliar nitrogen content than all other species, but in vitro organic matter digestibility was less than 700 g OM/kg DM. Although the wheatgrasses had satisfactory herbage yield and nutritional value, better alternative species are available for pastoral farming in central Hawke's Bay. On Belfield in the Hakataramea Valley, cv. Rush has been the most vigorous wheatgrass for establishment and it seems to handle cold winds and frost well. Hay made from a wheatgrass/ lucerne mix is considered better than that from the individual species as this can increase production by 40-50%, depending on soil and climatic conditions. Usually only one cut per year is taken from the mixed pasture. Crop maintenance includes the application of 200 kg/ha of sulphur super extra every 3-4 years and the pH is maintained at about 5.9-6.4 by liming. A significant advantage is that no stock health, pest or plant disease problems have been noted as yet with any of the wheatgrass varieties available in New Zealand. Keywords: dryland agriculture, New Zealand, Thinopyrum, wheatgrass



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