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321.
The applicability of ovule culture was examined in reciprocal crosses between the diploid species D. grandiflorum L. and the tetraploid cultivar D. hybridum ‘Galahad’. An interspecific hybrid plant of D. hybridum ‘Galahad’ × D. grandiflorum was obtained,and hybridity was confirmed by chromosome counting. The hybrid was different from the parents in flower color
and size but intermediate between the parents in leaf shape. The hybrid showed low pollen fertility and failed to produce
viable seeds by either self- or backcross-pollination using fertile pollen grains from its parents. The applicability and
efficiency of the ovule culture technique for genetic improvement of the genus Delphinium through interspecific hybridization between different ploidies is discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
322.
The melon (Cucumis melo) plant introduction PI 414723 was observed to segregate for resistance after inoculation with a highly
virulent non-aphid-transmissible strain of zucchini yellow mosaic potyvirus (ZYMV-NAT). By self-pollination of selected resistant
plants, the percentage of resistant plants increased in successive generations until nearly 100% in the S7 progeny. A reciprocal cross was made between a resistant S5 plant of PI 414723 and a plant of the susceptible cultivar Dulce. Parental-, filial-, and backcross- generation plants were
inoculated with ZYMV-NAT. One-half of the F1 plants, regardless of the direction of the cross, were resistant, indicating that the PI 414723 individual used for crossing
was heterozygous. The F2 generation obtained by self-pollination of resistant F1 plants segregated to resistant and susceptible in accordance with a 27:37 ratio, indicating that, in this cross, three complementary
dominant genes are needed for resistance to be expressed. The resistance to ZYMV carried by PI 414723 is oligogenic with the
number of genes observed to segregate in crossing depending on the genotype of the susceptible parent.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
323.
To estimate variations in pesticide residue levels in crops, the variability factors (VFs, the 97.5th percentile of the residue levels in the sample divided by the average residue levels in the lot) in residue levels of acetamiprid and cypermethrin applied to cabbage and grapes were investigated, respectively. The VFs in the residue levels of both pesticides in cabbage (2.00 and 2.39, respectively) were clearly higher than those in grapes (1.82 and 1.63, respectively). Although the residue levels of both pesticides in grapes showed a normal distribution, those values in cabbage were slightly skewed at lower residue levels. Individual residue levels in grapes had a good agreement between acetamiprid and cypermethrin. In contrast, the distribution of cypermethrin residue levels in cabbage was slightly skewed at higher residue levels as compared to that of acetamiprid. These results indicate that the difference in the relative distribution of the two pesticides between cabbage and grapes might be due to the influence of various factors such as differences in crop species, plant cultivation methods, and physicochemical properties of the pesticides. 相似文献
324.
Yamamoto M Sato S Hemmi H Hoshino K Kaisho T Sanjo H Takeuchi O Sugiyama M Okabe M Takeda K Akira S 《Science (New York, N.Y.)》2003,301(5633):640-643
Stimulation of Toll-like receptors (TLRs) triggers activation of a common MyD88-dependent signaling pathway as well as a MyD88-independent pathway that is unique to TLR3 and TLR4 signaling pathways leading to interferon (IFN)-beta production. Here we disrupted the gene encoding a Toll/IL-1 receptor (TIR) domain-containing adaptor, TRIF. TRIF-deficient mice were defective in both TLR3- and TLR4-mediated expression of IFN-beta and activation of IRF-3. Furthermore, inflammatory cytokine production in response to the TLR4 ligand, but not to other TLR ligands, was severely impaired in TRIF-deficient macrophages. Mice deficient in both MyD88 and TRIF showed complete loss of nuclear factor kappa B activation in response to TLR4 stimulation. These findings demonstrate that TRIF is essential for TLR3- and TLR4-mediated signaling pathways facilitating mammalian antiviral host defense. 相似文献
325.
Shibata K Nakamura T Matsumoto T Otsuji K Okamoto TJ Nishizuka N Kawate T Watanabe H Nagata S Ueno S Kitai R Nozawa S Tsuneta S Suematsu Y Ichimoto K Shimizu T Katsukawa Y Tarbell TD Berger TE Lites BW Shine RA Title AM 《Science (New York, N.Y.)》2007,318(5856):1591-1594
The heating of the solar chromosphere and corona is a long-standing puzzle in solar physics. Hinode observations show the ubiquitous presence of chromospheric anemone jets outside sunspots in active regions. They are typically 3 to 7 arc seconds = 2000 to 5000 kilometers long and 0.2 to 0.4 arc second = 150 to 300 kilometers wide, and their velocity is 10 to 20 kilometers per second. These small jets have an inverted Y-shape, similar to the shape of x-ray anemone jets in the corona. These features imply that magnetic reconnection similar to that in the corona is occurring at a much smaller spatial scale throughout the chromosphere and suggest that the heating of the solar chromosphere and corona may be related to small-scale ubiquitous reconnection. 相似文献
326.
Yan Tan Kiyoshi Osatomi Yukinori Nozaki Tadashi Ishihara Kenji Hara 《Fisheries Science》2006,72(1):185-194
ABSTRACT: We purified cathepsins B1 and B2 from the ordinary muscle of carp Cyprinus carpio . The N-terminal amino acid sequences (12 residues) of 29 kDa bands of cathepsins B1 and B2 are the same and showed high homology of 75% and 83%, respectively, with the heavy chain of rat and human cathepsins B. Based on conserved sequences of other cathepsins B and the N-terminal amino acid sequences of 29 kDa bands, we cloned carp cathepsin B cDNA. The nucleotide sequence of carp cathepsin B cDNA consists of 1470 bp including a 993 bp open reading frame, encoding a deduced protein of 330 amino acids. The deduced amino acid sequence of carp cathepsin B has similarity of 80% to rainbow trout cathepsin B and of 76–78% to other vertebrate cathepsins B. The sequence of its isoform was also determined during molecular cloning, which has 94.8% similarity with first cloned cathepsin B. They are completely same in N-terminal amino acid sequence of heavy chain, active site and potential N-glycosylation site. This indicates there are at least two kinds of cathepsin B functioning in vivo in carp. 相似文献
327.
Wenresti G Gallardo Atsushi Hagiwara Kenji Hara Kiyoshi Soyano 《Fisheries Science》2006,72(4):781-786
ABSTRACT: A growth hormone (GH)-like substance was extracted from the rotifer Brachionus plicatilis and subsequently purified by gel filtration and ion exchange chromatography. The GH-like substance had a molecular weight of approximately 28 kDa and had cross-reactivity with salmon GH antibody. In vivo bioassay showed a higher intrinsic rate of increase and net reproduction rate of B. plicatilis treated with the GH-like substance. 相似文献
328.
Weng WY Wu T Chen WQ Liu GM Osatomi K Su WJ Cao MJ 《Fish physiology and biochemistry》2011,37(3):543-552
Three pepsinogens (PG1, PG2, and PG3) were highly purified from the stomach of freshwater fish rice field eel (Monopterus
albus Zuiew) by ammonium sulfate fractionation and chromatographies on DEAE-Sephacel, Sephacryl S-200 HR. The molecular masses
of the three purified PGs were all estimated as 36 kDa using SDS–PAGE. Two-dimensional gel electrophoresis (2D-PAGE) showed
that pI values of the three PGs were 5.1, 4.8, and 4.6, respectively. All the PGs converted into corresponding pepsins quickly at
pH 2.0, and their activities could be specifically inhibited by aspartic proteinase inhibitor pepstatin A. Optimum pH and
temperature of the enzymes for hydrolyzing hemoglobin were 3.0–3.5 and 40–45°C. The K
m values of them were 1.2 × 10−4 M, 8.7 × 10−5 M, and 6.9 × 10−5 M, respectively. The turnover numbers (k
cat) of them were 23.2, 24.0, and 42.6 s−1. Purified pepsins were effective in the degradation of fish muscular proteins, suggesting their digestive functions physiologically. 相似文献
329.
Kiyoshi Soyano Toshihiko Saito Masaki Nagae Kohei Yamauchi 《Fish physiology and biochemistry》1993,11(1-6):265-272
Blood and ovarian samples were collected at intervals of 4h prior to spawning time from medaka (Oryzias latipes) that were maturationally synchronized with artificial photoperiod (14h light: 10h dark). Plasma estradiol-17β (E2) levels increased rapidly from 16h before spawning and peaked at 8h before spawning. Follicle-enclosed oocytes (ovarian follicles) at different stages of development were isolated from the ovaries and used to study the in vitro effects of thyroid hormone (triiodothyronine; T3) on pregnant mare serum gonadotropin (GTH)-induced E2 production. GTH at a concentration of 100 IU/ml stimulated E2 production by ovarian follicles collected between 32 and 16h before spawning. At 32h before spawning, T3 (5 ng/ml) administered along with GTH (100 IU/ml) resulted in a 3.5 fold increase in E2 production, compared with GTH administered alone. These results suggest that T3 can act on ovarian follicles directly to modulate GTH-stimulated E2 production in the medaka. 相似文献