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1.
S. V. Malyshev T. V. Dolmatovich A. V. Voylokov S. P. Sosnikhina N. V. Tsvetkova A. V. Lovtsus N. A. Kartel’ 《Russian Journal of Genetics》2009,45(12):1444-1449
Studies of phenotypical expression of synaptic mutations in combination with the localization of corresponding genes on a
genetic map permit individual stages of the meiotic process to be differentiated. Two rye asynaptic genes, sy1 and sy9, were mapped with the use of microsatellite markers (SSR) in the pericentromeric regions of the long chromosome arms 7R and
2R, respectively. The sy9 gene cosegregated with two SSR markers Xscm43 and Xgwm132. The asynaptic gene sy1 was mapped within the interval between the isozyme locus Aat2 and two cosegregating loci Xrems1188 and Xrems1135 that are located at a distance of 0.4 cM proximally and 0.1 cM distally with respect to the gene lous. Possible evolutionary
relationships of the mapped genes with homeological loci of the Triticeae species and more distant cereal species, such as maize and rice, are discussed. 相似文献
2.
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
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Tamara S. Al-Qudah Rida A. Shibli Feras Q. Alali 《In vitro cellular & developmental biology. Plant》2011,47(4):496-505
A protocol for in vitro propagation of the wild germander (Teucrium polium L.) was developed. In vitro plants were developed from ex vitro axillary buds. Then, shoot tips were excised and established on Murashige and Skoog medium. Proliferation of shoots was tested
with different levels of 6-furfurylaminopurin, 6-benzyladenine, or thiadiazuron. The highest proliferation of T. polium was obtained when 6-benzyladenine and 6-furfurylaminopurin were used at 2.0 and 1.6 mg l−1, respectively. Thiadiazuron gave the lowest response for shoot proliferation. Rooting was experimented at different levels
of Indol-3-butric acid, Indol-3-acetic acid, or 1-naphthaleneacetic acid. 1-Naphthaleneacetic was the only growth regulator
which promoted root induction. Rooted plants were acclimatized successfully with 75% survival and grown in the greenhouse.
In vitro- and in vivo-grown plants were analyzed for essential oil production. In vitro-grown T. polium on MS medium supplemented with 6-benzyladenine and 1-naphthaleneacetic gave higher oil yield than that grown on hormone-free
Murashige and Skoog medium. In vivo (wild)-grown T. polium produced different oil yield when collected in different months (April and October). β-caryophyllene, used as a marker compound
in the essential oil, was identified and quantified by gas chromatography (GC) analysis. Gas chromatography/mass (GC-MS) spectrometry
analysis was also used to identify other components of in vitro cultures and to compare with in vivo-grown plants. 相似文献
6.
S. E. Dawson 《Kew Bulletin》2008,63(3):517-517
Summary The name Pavetta modesta (Hiern) S. E. Dawson is a later homonym of P. modesta Bremek. Pavetta crystalensis is proposed as a new name. 相似文献
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Takehiko Yamanaka Koichi Tanaka Akira Otuka Ottar N. Bjørnstad 《Ecological Research》2007,22(2):185-196
We observed a weed (Ambrosia artemissifolia)–beetle herbivore (Ophraella communa) system for three years in a spatially continuous field (≈200 ha). We analyzed our field data in the light of two contrasting
theories: the resource-concentration hypothesis and reaction–diffusion theory. For the resource-concentration hypothesis, we calculated the correlation coefficients between weed and beetle abundances
for every season in each year. Although we found weak support for resource concentration in some seasons, we could not find
any clear relationships in other seasons. We discuss a dispersal-based mechanism to explain the differences observed among
seasons in lieu of the resource-concentration hypothesis. For the reaction–diffusion theory, we estimated the nonparametric
spatial covariance functions for the spatial autocorrelation of weeds and beetles. Although we could not find any strong spatial
structure for the individual species, we found evidence of spatial interactions between weeds and beetles using time lagged
cross-correlation functions. Weed abundance enhanced local beetle abundance. Through time, there was evidence of beetle spillover
to adjacent locations at roughly the one beetle-generation time scale. Sites with large number of beetles did not seem to
reduce subsequent weed abundance. 相似文献
9.
Selection on traits conferring reduced predation may be opposed by selection on other traits associated with reproduction.
Here, we examined the hypothesis that traits associated with reproduction in Gammarus pulex are driven by predation. We studied G. pulex originating from ponds with two different kinds of predator regimes: (1) ponds with fish—often large, non-gap-limited predators
and (2) ponds without fish where invertebrates are the dominant predators—often small, gap-limited predators with a much more
restricted prey size range. We examined the body size of males and females in G. pulex amplexus pairs originating from fish and fishless ponds. We also examined, in the laboratory, their mating success, the number
of offspring per female and offspring mortality under different rearing conditions, with or without fish cue. Mating success,
defined as the percentage of amplexus pairs that produced live offspring, was higher for G. pulex from fishless ponds independent of rearing condition. Individuals from fish ponds were larger and they produced a higher
number of offspring which tended to be related to female body size. Offspring mortality was higher in populations from fish
ponds compared to populations from fishless ponds. Despite the higher offspring mortality, females from fish ponds had a higher
number of offspring alive after 13 weeks, which is the approximate time it takes for G. pulex to reach maturity. Our data imply that no trade-off between reducing body size to reduce mortality caused by fish and maximising
reproductive success exist in G. pulex from fish ponds. The strategy with many offspring may be the correct strategy in fishponds where predation pressure generally
is higher than in fishless ponds. 相似文献
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Hiroki Saito Qingbo Yuan Yutaka Okumoto Kazuyuki Doi Atsushi Yoshimura Hiromo Inoue Masayoshi Teraishi Takuji Tsukiyama Takatoshi Tanisaka 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(2):315-323
A recently established rice breeding program in low latitudes aims to develop varieties with extremely long basic vegetative
growth (BVG) periods and weak photoperiod sensitivities. The Taiwanese japonica variety Taichung 65 (T65) harbors a recessive allele ef1 at the Ef1 (Early flowering 1) locus, thereby exhibiting an extremely long BVG period. The previous reported functional allele Ehd1 (Early heading date 1), located on chromosome 10, encodes a B-type response regulator, thereby shortening the BVG period, whereas its nonfunctional
allele ehd1 greatly prolongs the BVG period. A conventional analysis using F2 and F3 populations and a subsequent CAPS analysis based on the amino acid sequences of Ehd1 and ehd1 showed that Ef1 and Ehd1 were at the same locus. The CAPS analysis also indicated that the Taiwanese japonica varieties with extremely long BVG periods all harbor ef1, but that ef1 does not exist among indica and japonica varieties in the low latitudes. Since ef1 has not been found in any japonica varieties outside Taiwan, this allele might have originated in Taiwan. Sequence analysis revealed that the mutant allele
ef1-h, which prolongs the BVG period even more than ef1 does, harbors an mPing insertion in exon 2, which causes the complete loss of gene function. Our results indicate that both ef1 or ef1-h alleles can be used as new gene sources in developing rice varieties with extremely long BVG periods for low latitudes.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
11.
As a step toward greater understanding of the genetics of verticillium wilt resistance in plants, we report the sequencing
of a candidate wilt resistance gene, mVe1, from the mint diploid model species, Mentha longifolia (Lamiaceae). mVe1 is a putative homolog of tomato (Solanum lycopersicum L.) verticillium wilt (Ve) resistance genes. The mVe1 gene has a coding region of 3,051 bp. The predicted mVe1 protein contains a leucine-rich repeat domain, a common feature of plant disease resistance proteins. We compared 13 mVe1 alleles from three mint species. These alleles shared 96.2–99.6% nucleotide identity. We analyzed four M. longifolia populations segregating with respect to mVe1 alleles and wilt resistance versus susceptibility and found one association between mVe1 genotype and wilt phenotype. We conclude that mVe1 may play a role in mint verticillium wilt resistance, but variation for resistance in our segregating progenies is likely
polygenic. Therefore, further investigations of mVe1 and identification of additional candidate genes are both warranted. 相似文献
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Swasti S. Swain Tapasi Tripathy Pradipta K. Mohapatra Pradeep K. Chand 《In vitro cellular & developmental biology. Plant》2010,46(2):134-141
In vitro regeneration of black nightshade (Solanum nigrum L.) plants was achieved through callus-mediated shoot organogenesis followed by 30 d indoor ex vitro adaptation to nutritional stress under environmental ambience and thereafter 6-d outdoor acclimatization in pots prior to
field establishment. Relevant physiological parameters including pigment content, chlorophyll a fluorescence, net photosynthetic rate (P
N), transpiration rate (E), and stomatal conductance (g
s) of in vitro-regenerated plants were investigated during the course of ex vitro adaptation. During the first 4 d of indoor transplantation to potting substrate, there was a marginal reduction in the leaf
chlorophyll and carotenoid contents but P
N and E were strongly reduced. The stomatal conductance and E/P
N ratio were significantly higher in plants up to 20 d of indoor adaptation than those of comparable age grown naturally from
seeds. The shape of the OJIP fluorescence transient varied significantly with acclimatization, and the maximum change was
observed at 2.0 ms. The 2.0 ms variable fluorescence (V
j), 30 ms relative fluorescence (M
0), photon trapping probability (TR0/Abs), and photosystem II (PSII) trapping rate (TR0/RC) showed initial disturbance and subsequent stabilization during 30 d of indoor acclimatization. Energy dissipation (DI0/RC) and electron transport probability (ET0/TR0) showed an initial phase of increase during the 4 d after plants were transplanted outdoors. During the 6-d outdoor acclimatization
after transfer of plants to soil, no significant change in total chlorophylls and carotenoids, E, and g
s were observed, but P
N improved after reduction on the first d. The OJIP-derived parameters experienced change on the first d but were stabilized
quickly thereafter. There was no significant difference between outdoor acclimatized plants and those of the seed-grown plants
of comparable age with respect to photosynthetic and fluorescence parameters. Direct transfer of plants without indoor acclimatization,
however, showed a completely different trend with respect to P
N, E, and OJIP fluorescence transients. The bearing of this study on optimizing micropropagation is discussed. 相似文献
14.
Dynamics of growth and oxygen consumption during ontogenesis of insects with direct (striped shield bug Graphosoma lineatum L.) and indirect (cabbage moth Mamestra brassicae L.) development have been compared. The correlation between a character of energy metabolism alteration and peculiarities
of development of the insects has been shown. Cyclic decrease of oxygen consumption during molt and sharp dropping during
metamorphosis have been observed in insects with indirect development. The decrease of oxygen consumption has been observed
in insects with direct development only during molts. The coefficient a of allometric dependence of oxygen consumption on body weight of imago for cabbage moth was two times higher than that for
striped shield bug. 相似文献
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Source water utilized by four families of loblolly pine (Pinus taeda L.) was assessed by comparing the H isotope composition ('D) of xylem sap and of soil water from four depths (0-20 cm, 20-40 cm, 1.2 m, and 2.1 m) across 1 year. Soil water 'D values varied with soil moisture content in the well-drained, sandy site and at each of the four soil depths. In September and November 1997 and May through November 1998, xylem sap 'D values closely matched the soil water 'D values of the upper soil horizons (0-20 and 0-40 cm) and, therefore, reflected significant water uptake from upper regions of the soil profile. In March 1998, xylem sap 'D values closely matched the soil water 'D values of the 1.2 m soil depth and, therefore, indicated that trees during this portion of the growing season were obtaining their water from deep in the soil profile. Analysis of source water use with a two-ended mixing model in the 3 months of collection that exhibited a range of soil water 'D values across the soil profile confirmed that trees utilized different sources of water depending upon season of the year. In September 1997 and November 1998, source water uptake was primarily from the upper soil profile while in March 1998, source water uptake was from deep in the soil profile. With few exceptions, we did not find striking differences in source water use between drought-hardy families and those that were locally adapted. 相似文献
18.
Using scanning electron microscopy (SEM), the external morphology of all developmental stages (egg, oncomiracidium, diporpa,
just fused juvenile and adult) of the parasite, Eudiplozoon nipponicum (Monogenea, Diplozoidae), from the gills of carp was studied. During the ontogeny, the tegument, tegumentary and sensory
structures are subsequently developed. The tegument of free swimming oncomiracidium occurs in two types — the ciliated and
non-ciliated with numerous uniciliated sensory structures. An attachment apparatus starts to form during the oncomiracidium
stage. Further developmental stages are adapted to the environment of the gills. Tegumentary folds become more apparent later
in development and assist to the parasite’s attachment. In connection with its reproductive strategy, the two morphological
structures of diporpa (ventral sucker and dorsal papilla) appear to play important role. On the gills, two individuals need
to meet and these structures mediate the fusion between two diporpae. The hindbody of adult parasite is highly modified for
attachment. The haptor, folds and lobular extensions are most developed. The forebody is flexible and able to interact with
host gill tissue via the mouth and associated mouth structures. The process of food intake of the parasite was discussed. 相似文献
19.
H. R. Zabihi G. R. Savaghebi K. Khavazi A. Ganjali M. Miransari 《Acta Physiologiae Plantarum》2011,33(1):145-152
We have recently indicated the plant growth promoting activities of Pseudomonas sp. as well as their alleviating effects on some soil stressors such as salinity. This is because in recent years, biological
fertilizers have received special attention by scientists in sustainable agriculture. Accordingly, it is pertinent to specify
the beneficiary level of such soil bacteria on plant growth including phosphorous (P) uptake. Hence, the objectives were to
determine: (1) the plant growth promoting effects of the tested Pseudomonas sp., and (2) its combined effects with different P fertilization rates on the nutrient uptake (N, P, and K) and yield of
wheat (Triticum
aestivum L.) under greenhouse and field conditions. The experiments were factorially arranged on the basis of a completely randomized
block design with three replicates and were conducted at the Research Farm of Agriculture and Natural Resources Research Center
of Khorasan, Mashhad, Iran. P was fertilized at three levels including 0, 25 and 50 kg/ha P2O5. Pseudomonas sp. including Pseudomonas
fluorescens 153, P. fluorescens 169, P.
putida 4, and P.
putida 108 were tested. Activities such as production of ACC deaminase and IAA-like products, as well as P solubilization were among
the most important activities of the tested Pseudomonas sp. Such bacterial effects greatly enhanced wheat growth and yield under greenhouse and field conditions. The results also
showed that the effects of Pseudomonas sp. on wheat nutrient uptake and the effects of bacteria as well as P fertilization on wheat yield were significant. P.
putida 108 was the most effective strain enhancing wheat P uptake and grain yield under greenhouse (96 and 58%) and field (80 and
37%) conditions, respectively. Hence, although Pseudomonas sp. could be a suitable replacement for high P fertilization, however, the optimum wheat yield resulted when the bioinoculants
are combined with 50% (25 kg/ha P2O5) P fertilization. This finding has great agricultural and environmental implications. 相似文献
20.
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