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131.
132.
Growth and photochemical response of triazine-susceptible and -resistant rutabaga ‘Laurentian’ genotypes to cyanazine (chloro-s-triazine) and metribuzin (methylthio-as-triazine) were evaluated. The young seedlings of the susceptible rutabaga were killed when cyanazine or metribuzin were applied either pre- or post-emergence. The triazine-resistant rutabaga, however, displayed a differential response to these herbicides. Metribuzin applied pre-emergence killed the seedlings at 0.4 kg ha?1, and at 0.2 kg ha?1 the growth was severely affected. Cyanazine even at higher rates applied pre- or post-emergence failed to inhibit growth in these plants.Chlorophyll fluorescence in leaf sections at the cotyledonary, 2-leaf and 4-leaf stages in the susceptible plants increased by 130 and 172% in response to 10?5 M cyanazine and metribuzin, respectively, suggesting that Photosystem II reactions in these plants were severely impaired. In resistant plants, there was little or no leaf chlorophyll fluorescence (LCF) increase at this herbicide concentration. However, at 10?4 M cyanazine and metribuzin, the LCF in resistant plants increased significantly and the increase was greater in response to metribuzin (86%) than to cyanazine (51%). This indicates that with these triazine-resistant genotypes, metribuzin is relatively more potent and at high rates is capable of interfering with photosynthesis. 相似文献
133.
Imada T Abdul Rahman MA Kashiwazaki Y Tanimura N Syed Hassan S Jamaluddin A 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(1):81-83
Eight clones of monoclonal antibodies (Mabs) to Nipah virus (NV) were produced against formalin-inactivated NV antigens. They reacted positive by indirect immunofluorescent antibody test, and one of them also demonstrated virus neutralizing activity. They were classified into six different types based on their biological properties. These Mabs will be useful for immunodiagnosis of NV infections in animals and further research studies involving the genomes and proteins of NV. 相似文献
134.
De la Mora A Trigo F Jaramillo L Garfias Y Solórzano C Agundis C Pereyra A Lascurain R Zenteno E Suárez-Güemes F 《Veterinary immunology and immunopathology》2006,113(1-2):148-156
In this work we identified specific bovine leukocytes that were bound by the Mannheimia haemolytica adhesin molecule (MhA) and the biological effect on the leukocytes. Histochemical staining and flow cytometry showed that MhA bind neutrophils (90%) and monocytes (5%). MhA induced an oxidative response in purified neutrophils; this effect was 1.5-fold higher than the effect observed with control cells activated with Zymosan. Cellular binding by MhA was inhibited with GlcNAc and its oligomers, as well as by glycoproteins containing tri- and tetra-antennary N-glycosydically linked glycans. MhA-induced oxidative burst was significantly inhibited by GlcNAc, iodoacetamide, superoxide dismutase, and piroxicam (p<0.05). Our findings suggest that among bovine leukocytes, neutrophils are the main target for MhA, inducing production of oxidative radicals by non-opsonic mechanism that seem to play an important role in tissue damage during mannheimiosis. 相似文献
135.
Several members of the bacterial genus Brenneria are pathogenic on different tree species. Cell-free extracts from the bacterial phytopathogens Brenneria rubrifaciens, B. salicis, and B. nigrifluens induced production of the red pigment rubrifacine in the B. rubrifaciens bruI insertional mutant Br-212. Analysis of the bruI locus identified an adjacent open reading frame, designated bruR, with homology to luxR. High-performance liquid chromatography and mass spectrometry analysis of ethyl acetate extracts from wild-type B. rubrifaciens and Escherichia coli expressing the bruI gene identified two acyl homoserine lactone (AHL) peaks, N-(3-oxohexanoyl)-homoserine lactone (3OC6HSL) and N-hexanoyl-homoserine lactone (C6HSL). Addition of synthetic 3OC6HSL and C6HSL at 10 μM to the bruI mutant, strain Br-212, induced rubrifacine production and the ability to elicit a hypersensitive reaction (HR) in tobacco leaves. Synthetic C6HSL was less effective at inducing pigment production than 3OC6HSL at 10 μM. The bruI mutant Br-212 did not produce detectable AHLs, indicating that C6HSL and 3OC6HSL are the major AHLs produced by this species. The AHLs N-heptanoyl-DL-homoserine lactone (C7HSL), N-octanoyl-DL-homoserine lactone (C8HSL), and N-(3-oxooctanoyl)-DL-homoserine lactone (3OC8HSL) also induced pigment production in Br-212 and restored its ability to elicit an HR in tobacco, suggesting that cross-talk with other bacterial species may be possible. 相似文献
136.
Naeem AbbasSarfraz Ali Shad Muhammad Razaq 《Pesticide biochemistry and physiology》2012,103(3):181-188
Imidacloprid has been used as a key insecticide for controlling sucking insect pests of cotton, whereas Spodoptera litura also has been indirectly exposed to this insecticide in Pakistan. To evaluate the risk of resistance evolution and to develop a better resistance management strategy, a field collected population was selected with imidacloprid in the laboratory. Thereafter, fitness cost, realized heritability and cross resistance of imidacloprid resistance in S. litura were investigated. After 14 generations of selection with imidacloprid, S. litura developed a 137.48-fold resistance to the insecticide. Bioassay revealed that this strain showed cross-resistance to acetamiprid (RR 8.52) and a little to lamdacyhalothrin (1.92) but negative cross-resistance was found to methomyl (−0.19). The resistant strain had a relative fitness of 0.38, with substantially lower rates of larval survival, larval duration, male pupal duration, development time, emergence rate of healthy adults, fecundity, hatchability, and prolonged larval and pupal duration. Mean relative growth rate of the larvae, intrinsic rate of population increase, and biotic potential was lower for the selected populations. The estimated realized heritability (h2) of imidacloprid resistance was 0.15 in the resistant strain of S. litura. Development of the resistance may cost significant fitness for the resistant population. This study provided valuable information for further understanding the impact of imidacloprid resistance on physiological parameters of S. litura and for facilitating the development of resistance management strategies. 相似文献
137.
根据塔克拉玛干沙漠北缘荒漠过渡带哈德、肖塘2个试验点的风、温梯度观测数据,利用风速比法计算了中性大气层结、无风沙运动条件的空气动力学粗糙度[WTBX](z0),并分析探讨z0[WTBZ]与下垫面状况、大气稳定度及风速的相互关系。结果表明:哈德、肖塘中性条件下z0的取值范围分别为 1.81×10-11~1.20×10-3 m,1.00×10-11~1.65×10-3 m,平均值为2.70×10-5 m 和6.05×10-5 m,与平坦沙面的值较为接近;z0随下垫面性质变化明显;空气动力学粗糙度总体上随着理查逊数(Ri)增大而变大,但又呈现出一定的离散程度;空气动力学粗糙度与2 m高度风速呈显著的负指数关系;大气稳定度对空气动力学粗糙度的影响作用有待于进一步确定。 相似文献
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140.
A crossbreeding experiment was carried out to determine the sire breed effects on fattening performance of fat-tailed lambs.
Rams from four Iranian fat-tailed sheep breeds, namely Kurdi (K), Afshari (A), Chaal (C) and Sanjabi (S) were mated to Kurdi
ewes producing 454 progeny of four genotype groups (KK, AK, CK and SK). A total of 80 lambs comprising ten female and ten
male lambs from each genotype group were used in a fattening experiment during a period of 88 days. Genotype of the lamb had
significant effect on average dry matter intake (ADMI) (P < 0.05). SK lambs had the lowest ADMI. Average daily gain (ADG) and food conversion ratio (FCR) were not influenced by genotype
of the lamb. Sex of the lamb had significant effect on both ADG and FCR (P < 0.01). Slaughter weight (SLW), hot carcass weight (HCW), cold carcass weight (CCW) and daily carcass gain (DCG) were not
affected by lamb's genotype. However, genotype had significant effect on dressing percentage, carcass loss percentage (P < 0.01), carcass length (CL), leg circumference (LC), carcass compactness (CC) (P < 0.01) and carcass density (CD) (P < 0.05). Carcass width (CW) and leg length (LL) were not affected by lamb's genotype. Sex of the lamb had significant effects
on CL, CW, LC, CC, CD (P < 0.01) and LL (P < 0.05). The results indicated the existence of sire breed difference for daily dry matter intake and carcass conformation
in the fat-tailed sheep. 相似文献