共查询到20条相似文献,搜索用时 15 毫秒
1.
Daniel J. Royse Jose E. Sanchez Robert B. Beelman James Davidson 《World journal of microbiology & biotechnology》2008,24(3):319-325
Experiments were performed to determine the effect of adding nutrient supplements to colonized mushroom compost (MC) for the
production of a second crop of mushrooms. Mushrooms were harvested for 1, 2 or 3 flushes, the casing removed and the MC then
was fragmented and re-supplemented with delayed release supplements treated or non-treated with fungicide (thiophanate-methyl;
Topsin M 70WP) and re-cased. Overall double-crop yields were higher when MC was re-supplemented after 1st flush (1st flush
MC) as compared to re-supplementation after the 2nd or 3rd flushes. Mean double-crop BEs were 128, 119 and 109% when 1st-,
2nd- and 3rd-flush MCs were used, respectively. Treatment of delayed release supplement with thiophanate-methyl fungicide
did not affect mushroom yields. Soluble salts and potassium concentrations increased 350 and 900%, respectively, in the casing
overlay through three flushes suggesting that removal of the casing would help to alleviate the build up of these potential
growth-limiting materials. Re-supplementing and re-casing of MC represents a potential opportunity for growers to increase
revenues and reduce costs associated with preparation and disposal of compost. The ability to double-crop mushroom compost
would provide growers a chance to increase yields by 40% or more, depending on whether they re-supplement and re-case after
1st, 2nd or 3rd flush. 相似文献
2.
Luciano Elias Oliveira Kátia G. Facure Ariovaldo A. Giaretta 《Environmental Biology of Fishes》2012,93(1):89-94
We present data on the habitat, density, and spatial distribution of Rivulus giarettai, and discuss some biotic and abiotic variables related to its abundance in Free Flowing Waters (FFW) and Dam Reservoirs (DR)
in palm grove (Mauritia flexuosa) marshes (Veredas) in Uberlandia, Minas Gerais, southeastern Brazil. The mean density (individuals/plot) of R. giarettai was about 13 times higher in FFW than in DR. In FFW, the density of R. giarettai was highest at intermediate amounts of substrate (plant mass) and it was positively rank-correlated with the depth, and the
number of arthropods. Individuals occurred in an aggregated distribution. The aggregated pattern could be related to a concentration
of individuals in microhabitats neither too much exposed nor completely saturated by plants. R. giarettai was relatively abundant and tolerant to slight man-made habitat modifications. Damming appeared to be especially problematic
by negatively affecting its density. 相似文献
3.
I. Rosario G. Soro S. Déniz O. Ferrer F. Acosta D. Padilla B. Acosta 《Mycopathologia》2010,169(4):315-319
Columba livia is an important reservoir and carrier of Cryptococcus neoformans, Cryptococcus uniguttulatus, Cryptococcus laurentii and Cryptococcus albidus. Upper digestive tract of this species is also known as a habitat for Cryptococcus neoformans. Given the increasing clinical interest of this microorganism, 331 swabs from crop and 174 dropping samples from pigeon lofts
in Grand Canary Island have been studied. The obtained results show an extensive presence samples 81 positive (24.47%) of
Cryptococcus spp. in analysed crops: 32 (9.66%) for C. neoformans, 24 (7.2%) for C. uniguttulatus, 23 (6.9%) for C. albidus and 2 (0.6%) for C. laurentii. In the same way, Cryptococcus spp was also isolated in 82 (47.13%), dropping samples: C. neoformans in 59 (33.9%), C. uniguttulatus, in 9 (5.17%), C. laurentii in 8 (4.59%) and C. albidus in 6 (3.44%) of the investigated samples, respectively. The cryptococcosis produced by species of cryptococci other than C. neoformans has become more important during the last decade, supporting the study on the role of pigeon in the epidemiology of this
disease. 相似文献
4.
Ana Neves Vera Sequeira Ana Rita Vieira Rafaela Paiva Leonel Serrano Gordo 《Hydrobiologia》2009,636(1):479-488
The importance of cephalopods in marine ecosystems is well recognized as they serve as important predators and prey in many
food chains. During a 1-year period, cuttlefish were monthly sampled in five areas throughout the Sado estuary, and the stomachs
of 445 individuals were examined. Significant changes in the diet according to their life stage were revealed, but similar
food habits were presented by males and females. Juvenile individuals (the smaller ones with no visible distinct gonads) preyed
mainly upon small crustaceans, while the immature ones (maturity stages I and II) had the most diverse diet with brachyurans
as the major prey group. The mature individuals (maturity stages III and IV) showed a clear preference for larger crabs and
fishes. Although the cuttlefish are known for their opportunistic feeding behaviour, a preference for some prey according
to length and behaviour could be perceived during this study. Seasonal differences in the diet were mostly due to the variation
of individuals according to their maturity stage during the year. 相似文献
5.
Bhavna Gupta B. P. Niranjan Reddy Anil S. Kotasthane 《World journal of microbiology & biotechnology》2011,27(1):1-9
Existence of variability in morphological traits and growth rate of mycelium of homokaryotic single basidiospores can be exploited
for the development of inter-strainal hybrids. We isolated 182 single basidiospores from mushroom bodies of P. sajor-caju, P. florida, P. eous and one wild relative of Pleurotus called Hypsizygus
ulmaris. The single spores were isolated using a new technique that is less prone to contamination and more efficient than the common
techniques used by earlier workers. All the isolates showed a varied range of cultural morphology. Mating types of all the
isolates within the species were identified on the basis of hyphal fusion via anastomosis with the tester strains. Four compatible
pairs of isolates with well prominent tuft in the contact zone were selected for dikaryon isolation. Dikaryons were used for
spawn preparation and mushroom cultivation. The dikaryotic isolates with their replicates were evaluated for spawn run period,
yield and biological efficiency. 42 isolates (10 di- and 32 mono-karyotic isolates) were analyzed with RAPD genetic markers.
Phenotypic characters and mating types of all the 42 isolates analyzed genetically were correlated with their genetic polymorphism
data. The isolates showed very large diversity both at the phenotypic and the genotypic level. Available phenotypic and genotypic
data can further help in the selection of monosporous isolates for developing inter-strainal hybrids which can lead to better
prospects for genetic improvement in different species of Pleurotus. 相似文献
6.
Mushroom bodies are prominent brain neuropils present in most arthropod representatives. Similar structures in the brain of
certain polychaete species are possibly homologous to these structures. Using three-dimensional reconstruction techniques,
we investigated the structural composition of the mushroom body neuropils in the polychaete species Nereis diversicolor and Harmothoe areolata. Comparative analysis revealed a common organization of neuropil substructures in both species that closely matches the basic
assembly of arthropod mushroom bodies. Concurring with earlier homology assessments, these neuroarchitectural similarities
provide support for a common origin of mushroom body neuropils in polychaetes and arthropods. Beyond that, differences in
the morphological differentiation of neuropil substructures indicate polychaete mushroom bodies to show a high degree of morphological
variability, thus impeding the quest for a common ground pattern of these brain centers. 相似文献
7.
Genetic variability of modulus of elasticity (MOE) was investigated in three genetic trials, including two progeny (16 years
old) and one clonal (19 years old) trials of hybrid larch (Larix x eurolepis Henry). MOE was directly assessed on standing trees using the Rigidimeter, a bending device, and related to other traits
including height, BH diameter and wood density. Mean MOE ranged from 5,183 to 9,228 MPa among families in the progeny trials
and from 4,591 to 11,486 MPa in the clonal trial. Among traits studied, MOE was one of the most variable traits. It was strongly
and positively related to wood density at both the individual and genotype mean levels. Interestingly too, wood stiffness
did not seem, or only weakly, unfavourably linked to stem diameter at the phenotypical level, but it was negatively or not
correlated to diameter at the genetic level. As well, MOE showed a high GxE stability over the two progeny trial sites. Narrow-sense
heritabilities for MOE were moderate (around 0.36). In all three trials, they were lower than those for wood density or total
height, and of the same level as for diameter. Improvement of wood stiffness of hybrid larch using the Rigidimeter seems possible
and promising genetic gains are expected. Impacts of selection for growth traits on MOE are also discussed. 相似文献
8.
Marcin Sielezniew Izabela Dziekańska Anna M. Stankiewicz-Fiedurek 《Journal of Insect Conservation》2010,14(2):141-149
Phengaris (=Maculinea) arion is an endangered social parasite of Myrmica ants, and for a very long time was considered as specific to Myrmica sabuleti. Previous studies carried out in Poland suggested some discrepancies within this assumption, and therefore a much more intensive
survey was undertaken. The host ant use of P. arion was studied at five sites in different types of biotopes in Poland, i.e. xerothermal grasslands where Thymus pulegioides was used as a larval food plant by the butterfly, and more or less sandy biotopes with Thymus serpyllum. Altogether nine Myrmica species were recorded, and considerable variation in species composition and density of nests was recorded. At four localities
M. sabuleti proved to be the most common ant. A total of 529 Myrmica nests were examined, and only 20 of them contained larvae and pupae of P. arion. Host ants belonged to five different species, i.e. M. sabuleti, Myrmica scabrinodis, Myrmica schencki, Myrmica lobicornis and Myrmica hellenica. Only at one site (NE Poland) was a significant heterogeneity in parasitation rates among Myrmica species detected. M. lobicornis was the most often infested ant there, which may suggest local specialisation of the butterfly. Overall low parasitism rates
may explain the vulnerability of P. arion in Central Europe but further studies are also necessary. 相似文献
9.
H. Khosravinia 《Russian Journal of Genetics》2009,45(1):98-104
This study was undertaken to evaluate the impact of slow/rapid feathering sex-linked gene on carcass weight (CW) and yield
(CY) as well as carcass main parts in an experimental colored broiler flock employing to evaluate the response to selection
for breast and thighs weight with imposing restriction against low value portions of carcass over three generations. Random
samples of the birds were slaughtered to evaluate the carcass traits at 42 days of age. Cut up yield was determined by partitioning
each carcass to breast, thighs as high value parts and wings, neck, rack and saddle as low value portions (LVP). Live body
weight (BW; 42d) and legs yield (LY) as a proportion of carcass weight (as % CW) were significantly greater for k
+
k
+/k
+
W genotypes compared to K-/KW bearing birds (P < 0.05). Intersex t test comparisons revealed significant superiority of the k
+
k
+ genotype over K- in male birds for LY (as % CW) and LY (as % BW) (P < 0.05). Interfamily analysis for eight larger half-sib families revealed infrequent superiority of K-/KW bearing birds over their sibs with the alternate genotype for breast yield (BrY; as % CW), legs weight (LW) and LY (as %
CW) in two families. Interfamily and interfemales analysis for seven larger half-sib families showed highly significant superiority
for k
+
W birds in LW (as % CW), BW and LVW in two families (P < 0.01). Considering feathering rate as a fixed effect (KW vs. k
+
W) to analyze the females data revealed significantly greater means for fast feathered females (k
+
W) for BW, CW, breast weight, LW and LVW than the alternate genotype (P < 0.05). It is concluded that in the today straight-run broiler flocks with numerous influencing factors of margin effects,
and with increasing demands for uniformity of carcass market where sexable day-old chicks are not of interest, to launch the
fast feathering gene (k
+) could be of positive economic consequences in broiler production.
The text was submitted by the autor in English. 相似文献
10.
There are three most important bacterial causative agents of serious infections that could be misused for warfare purposes:
Bacillus anthracis (the causative agent of anthrax) is the most frequently mentioned one; however, Fracisella tularensis (causing tularemia) and Yersinia pestis (the causative agent of plague) are further bacterial agents enlisted by Centers for Disease Control and Prevention into the category A of potential biological weapons. This review intends to summarize basic information about these bacterial
agents. Military aspects of their pathogenesis and the detection techniques suitable for field use are discussed. 相似文献
11.
12.
Jorge Hernandez Valeria Prado Daniel Torres Jonas Waldenström Paul D. Haemig Björn Olsen 《Polar Biology》2007,30(10):1227-1229
Rectal swabs were collected from Antarctic fur seal pups Arctocephalus gazella at Cape Shirreff, South Shetland Islands, and analyzed for the presence of anthropogenic pathogens. Two of the 33 pups tested
positive for enteropathogenic Escherichia coli (EPEC). These samples are the first records of EPEC in Antarctic wildlife and suggest that more needs to be done to protect
the Antarctic fauna from exotic anthropogenic pathogens. 相似文献
13.
D. N. Malysheva V. I. Korchagin O. N. Tokarskaya A. P. Ryskov 《Russian Journal of Genetics》2012,48(3):268-275
In the genome of unisexual (parthenogenetic) lizard Darevskia armeniaca, highly variable locus Du161 (arm) was discovered. Analysis of allelic polymorphism was carried out using locus-specific PCR of the lizard DNA specimens from
13 isolated Armenian populations (N = 138). In the sample examined, a total of 12 Du161(arm) alleles were identified, and their differences at the level of primary DNA structure were determined. Sequence analysis of
the Du161(arm) alleles showed that their microsatellite clusters contained repeats of one type (GATA repeats). Allelic Du161(arm) variants differed in the number of GATA monomers in microsatellite, point mutations of transition and transversion types,
located at fixed distances from micro-satellite cluster, and by single nucleotide insertions, as well as by longer insertions
located within and outside of the microsatellite cluster. Moreover, point mutations formed different combinations (haplotypes),
typical of certain alleles. These combinations can be used for the analysis of the origin and inheritance of these alleles
in D. armeniaca, as well as for investigation of their interspecific variation in the representatives of the genus Darevskia. 相似文献
14.
Rui Fernando da Silva Andréa Carla de Almeida Barros Márcia Pletsch Adriana Carla Cavalcante Malta Argolo Brancilene Santos de Araujo 《World journal of microbiology & biotechnology》2010,26(10):1761-1767
Scavenging and anti-Staphylococcus
aureus activities of extracts, fractions and subfractions from the in vitro mycelium of two strains of the edible mushroom Volvariella volvacea were determined. Chloroform subfractions of the ATCC62890 strain showed the highest inhibition percentage of the DPPH radical
(over 80%) after 180 min. When chloroform and hexane subfractions of the R83 strain were combined they showed moderate (inhibition
zone of 8.99 ± 0.78 mm) to high (inhibition zone of 13.06 ± 0.41 mm) activity against the Gram-positive bacteria Staphylococcus
aureus, which are 74.4 and 51.2% of tetracycline (inhibition zone of 17.55 ± 0.11 mm). Partitioning suggested that the substances
in the chloroform and hexane fractions of the R83 strain act synergistically to give the antimicrobial activity, while separating
the substances of the ATCC62890 subfractions reduced their activity. In general, the R83 strain seems to be a source of antimicrobial
substances, while the ATCC62890 strain appears to be an alternative source of antioxidants. 相似文献
15.
16.
Eustáquio Souza Dias Cláudia Regina Gontijo Labory Karina Marjorie Silva Herrera Alexandre Alonso Alves Giovana Augusta Torres Danny Lee Rinker 《World journal of microbiology & biotechnology》2008,24(11):2473-2479
Agaricus brasiliensis is a medicinal mushroom native to Brazil. It was first identified as Agaricus blazei and its scientific name continues to be debated. We examined the cytology of different Brazilian commercial strains of A. brasiliensis and the nuclear behavior of strain CS1 during basidiospore development using fluorescent microscopy. All strains have multinucleate
hyphae and no significant differences in nuclei numbers were observed between them. Basidia from A. brasiliensis strain CS1 are typically tetrasporics and produce binucleate basidiospores, demonstrating that a postmeiotic mitosis occurs
during basidiospore development. This result suggests that A. brasiliensis is primarily a heterothallic species. 相似文献
17.
Mature seed-derived embryogenic calli of indica rice (Oryza sativa L. cv. PAU201) were induced on semisolid Murashige and Skoog medium supplemented with 2.5 mg dm−3 2,4-dichlorophenoxyacetic acid + 0.5 mg dm−3 kinetin + 560 mg dm−3 proline + 30 g dm−3 sucrose + 8 g dm−3 agar. Using OsglyII gene, out of 3180 calli bombarded, 32 plants were regenerated on medium containing hygromycin (30 mg dm−3). Histochemical GUS assay of the hygromycin selected calli revealed GUS expression in 50 % calli. Among the regenerants,
46.87 % were GUS positive. PCR analysis confirmed the presence of the transgene of 1 kb in 60 % of independent plants. Further,
these plants have been grown to maturity in glasshouse. In vitro screening for salt tolerance showed increase in fresh mass of OsglyII putative transgenic calli (185.4 mg) as compared to control calli (84.2 mg) on 90 mM NaCl after 15 d. When exposed to 150
mM NaCl, OsglyII putative transgenic plantlets showed normal growth while the non-transgenic control plantlets turned yellow and finally did
not survive. 相似文献
18.
Hail Z. Rihan Mohammed Al-Issawi Stephen Burchett Michael P. Fuller 《Plant Cell, Tissue and Organ Culture》2011,107(2):243-250
An effective protocol for the mass production of cauliflower microshoots was refined using the meristematic layer of cauliflower
curd. After the meristematic layer was surface sterilized and shaved off, a commercial blender was used for homogenization
and several blending treatments were tested in the range 15–120 s and 30 s was found to be optimal in terms of the amount
explants produced and their subsequent growth ability. Explants were cultivated in S23 liquid medium (4.4 g L−1 MS (Murashige and Skoog) and 3% v/w sucrose) supplemented with several combinations of plant growth regulators (PGRs) including
1 and 2 mg L−1 of Kinetin in combination with three types of auxins (indole butyric acid (IBA), Naphthaleneacetic acid (NAA) and Indole-3-acetic
acid (IAA)), each at 1 and 2 mg L−1 concentration. The use of 2 mg L−1 Kinetin and 1 mg L−1 IBA gave the best results in terms of its effects on explant induction. Microshoots of different sizes were encapsulated
in a sodium alginate matrix and the optimal stage suitable for the production of artificial seeds was assessed in terms of
both subsequent conversion and plantlet viability. The feasibility of cultivating cauliflower artificial seeds in commercial
substrates (compost, vermiculite, perlite and sand) irrigated with different solution mixtures including sterilized distilled
water (SDW), PGRs-free S23 medium and S23 medium supplemented with Kinetin (1 and 2 mg L−1) and IBA or NAA at (1 and 2 mg L−1) was investigated. The use of 2 mg L−1 Kinetin and 2 mg L−1 NAA applied with S23 gave the optimal response with both perlite and compost. This study showed high growth capacity of cauliflower
artificial seeds in commercial substrates which is considered a promising step for their direct use in vivo. 相似文献
19.
Submerged macrophytes are known to serve as refuge for zooplankton but also seem to suppress the zooplankton growth. Thus,
there is a conflict between the positive and negative role of macrophytes for zooplankton. We tested the influence of physical
structure using artificial macrophytes, chemicals released by a macrophyte (Myriophyllum verticillatum), as well as the combined effects of these two factors on the life history of Daphnia magna. Daphnids matured at a smaller size and produced fewer eggs but larger individual offspring in the presence of artificial
and real plants. Thus, under conditions with plants, we observed a trade off between number of eggs produced and the individual
size of the offspring. Daphnids grown in the presence of exudates without plants were larger at maturity and showed no reduction
in clutch size as compared with the control. We suggest that the macrophytes (real and artificial) negatively affected the
daphnids in two ways: (1) food particles were settling down faster on the plant structures and this reduced the available
food for Daphnia, (2) the plant structures were obstacles for the daphnids causing them to spent more energy during swimming. Both effects
resulted in a reduced somatic growth, whereas the increased individual offspring size was probably a response to the reduced
food level. Daphnia was not negatively affected by Myriophyllum exudates. 相似文献
20.
A branched mid-Holocene bamboo coral skeleton of the isidid gorgonian genus Keratoisis (Octocorallia) recovered at southwestern Chatham Rise (New Zealand) from an average water depth of 680 m is described with
respect to sclerochronology and age determination. Growth rates of the Mg-calcitic internodal increments were investigated
by the counting of colour bands and radiocarbon dating. Growth banding is produced by varying orientations of crystal fan
bundles towards the image plane. The skeleton shows three growth interruptions, which are documented in all branches. AMS
14C ages decrease from base to top of the trunk and from the central axes to the margins of the branches, documenting a simultaneous
vertical and lateral growth. The data provide a maximum age of 3,975 ± 35 years BP, and a record spanning 240 ± 35 years. While calculated longitudinal growth rates amount to an average of 5 mm year−1 during a 55-year record, average lateral linear extension rates of 0.4 mm year−1 are an order of magnitude lower, still allowing for a seasonal to annual resolution of colour bands on a macroscopic scale
and for a daily to monthly resolution on microscales of individual crystal generations to fascicle bundles. Hence, the isidid
skeleton provides a high-resolution archive of paleoceanographic dynamics in deeper water masses. Concentric incremental accretion
around the central axis in the early growth stages changed into a unilaterally asymmetric growth during late-stage evolution,
probably triggered by the establishment of a stable system of unidirectional currents and nutrient flux. While colour band
counts, related to the AMS 14C ages, support a seasonal to annual accretion of macroscopic growth bands in the inner concentric and complete outer parts
of the skeleton, incremental growth rates at the condensed side are highly variable, as documented by hiatuses and unconformities.
Thus the specimen proves that growth rates of bamboo corals may vary within individual skeletons and strongly deviate from
the annual mode, hence showing implications on paleoceanographic proxy analyses. 相似文献