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121.
Marcelo Grandi Teixeira José Guilherme Marinho Guerra Dejair Lopes de Almeida Adelson Paulo Araújo Avilio Antonio Franco 《Journal of plant nutrition》2013,36(10):1599-1611
Abstract An experiment was conducted in the greenhouse to evaluate the effects of seed phosphorus (P) concentration on growth, nodulation, and nitrogen (N) and P accumulation of three common bean (Phaseolus vulgaris L.) cultivars. Seeds were produced under low or high soil P levels, and soaked, or not, in 200 mM KH2PO4 solution. The experiment had a 3×3×2×2 factorial block design: three cultivars (ICA Col 10103, Carioca and Honduras 35), three levels of applied P (15, 30 and 45 mg P kg?1 soil), two native seed P concentrations, and two seed soaking treatments. Plants were harvested at flowering. Soaked seeds increased the number, dry mass and P content of nodules, but did not affect plant growth. Plants originated from seeds with high native P concentration presented higher shoot dry mass and nodule number and mass at every soil P level, and were less responsive to increased soil P supply, than plants from low seed P. In plants from seeds with high P, soil P levels did not alter significantly root dry mass, while in plants from seeds with low P bean cultivars expressed wider differences in root dry mass. The genotypic variability of nodulation was influenced by soil P levels and seed P concentration. Both higher soil or seed P supply enhanced N and P accumulation in shoots. These results indicate that a high seed P concentration produces plants less dependent on soil P supply, and can enhance nodulation and N2 fixation of common bean. Seed P supply affected the cultivar performance, and should be considered in evaluation of bean genotypes. 相似文献
122.
Lax Paola Rondan Dueñas Juan C. Andrade Alberto J. Doucet Marcelo E. 《European journal of plant pathology / European Foundation for Plant Pathology》2021,160(2):397-409
European Journal of Plant Pathology - Trichoderma aggressivum, a mycopathogen causing green mould disease, is a major problem in Agaricus bisporus cultivation due to crop loss, and resistance to... 相似文献
123.
Barley alpha-amylase isozymes 1 (AMY1) and 2 (AMY2) have 80% sequence identity but possess different physico-chemical properties. By incubation in the range 37–85 °C T50 is 75.2 °C of AMY1 and 79.2 °C of AMY2. While AMY2 is also most stable in urea at pH 6.7, [urea]50 being 8.2 M compared to 7.9 M for AMY1, AMY1 has highest stability in urea below pH 6 or in the presence of NaCl. Moreover AMY1 is most stable in guanidinium chloride. Charge screening thus destabilises AMY2 but stabilises AMY1. Isozyme sequence comparison suggests that AMY1 lacks four of the 20 salt-bridges identified in the crystal structure of AMY2. The four residues that differ comprise Lys67AMY2 and Asp267AMY2, forming salt-bridges on the surface of the catalytic (β/α)8-barrel (domain A), and Glu96AMY2 and His344AMY2 that participate in charged networks between domain A and the small domain B and the C-terminal domain, respectively. Four corresponding AMY2 mimics A68K; D97E; Q269D; N346H were made in AMY1 by site-directed mutagenesis. While D97E and Q269D have slightly improved stability compared to AMY1 wild-type, N346H and, under certain conditions, A68K are destabilised. The four mutants show 22–176% activity (kcat/Km) toward 2-chloro-4-nitrophenol β-
-maltoheptaoside and amylose DP17 and 43–117% activity for insoluble starch. 相似文献
124.
de Sá Silvia Ferreira dos Santos Luísa C. Aragão da Conceição Léo D. H. C. Schwartzhaupt Braga Marcelo Fideles Laviola Bruno Galvêas Cardoso Alexandre Nunes Sayd Ricardo Meneses Junqueira Nilton T. Vilela 《Genetic Resources and Crop Evolution》2021,68(8):3193-3204
Genetic Resources and Crop Evolution - Macauba [Acrocomia aculeata (Jacq.) Lodd. ex Mart.], a palm tree native to Brazil, has a high potential as an alternative source for vegetal oil production.... 相似文献
125.
Brenda Colleen Clifton-Cardoso Marcelo Schramm Mielke José Roberto De Melo Rondinele Nascimento Querino 《New Forests》2008,35(1):15-31
Dimorphandra jorgei MF Silva (Caesalpinaceae) and Swartzia macrostachya Benth. var. riedelii Cowan (Fabaceae) are tree species from the southern Bahian Atlantic Forest, identified for the restoration of degraded areas.
The objective of this research is to study their seed germination and seedling growth to develop simple methods for seedling
production in small scale nurseries. Because the species have distinct dormancy and germination characteristics, the seeds
were submitted to different treatments. D. jorgei seeds were immersed in hot water, scarified and stored for 12 weeks in the laboratory environment (25°C). S. macrostachya seeds were submitted to different combinations of drying and storage in the laboratory environment or refrigerator (4°C).
Seedlings were submitted to two light treatments for 3 months: partial shade (52% of full sun) and full shade (12% of full
sun). In D. jorgei, the highest germination occurred for scarified seeds (87%) and for seeds stored for 12 weeks and then scarified (69%). In
S. macrostachya the undried control seeds had the highest germination, followed by that of the refrigeration storage treatment, without predrying
(99% and 97%, respectively). The average values for the growth parameters were greater in full shade for D. jorgei, while S. macrostachya seedlings showed greater growth rates in partial shade. Two months growth is recommended before D. jorgei seedlings are of the sufficient size and leaf number for field planting. On the other hand, a period of 4 months is recommended
for S. macrostachya, due to its relatively slow growth. 相似文献
126.
Julio C. Barbosa Sarah S. Barreto Alice K. Inoue-Nagata Marcelo S. Reis Ana Carolina Firmino Armando Bergamin Filho Jorge Alberto Marques Rezende 《Journal of General Plant Pathology》2009,75(6):440-443
Nicandra physaloides, a common weed in South America, was found to be infected by an isolate of Tomato severe rugose virus (ToSRV), a bipartite begomovirus. The plants developed severe yellow rugose mosaic and were collected in São Paulo State, Brazil. This isolate of ToSRV was transmitted by Bemisia tabaci B biotype from infected plants of N. physaloides to healthy plants of N. physaloides and tomato in a glasshouse. This is the first report of natural infection of N. physaloides by ToSRV in Brazil. 相似文献
127.
Flaviano O Silvério Elson S de Alvarenga Shaiene C Moreno Marcelo C Picanço 《Pest management science》2009,65(8):900-905
BACKGROUND: Pyrethroids are among the most potent pesticides known, with great potential for structural variation with retention or enhancement of potency. The simple methyl ester is easier to prepare (at least one step shorter) than the more complex pyrethroids modified on the alcohol moiety. The objective was to synthesise methyl esters of pyrethroid acids containing an aromatic ring on the acid moiety and evaluate their biological activity against Ascia monuste orseis Latr., Tuta absoluta Meyrick, Periplaneta americana (L.), Musca domestica L. and Sitophilus zeamais (Motsch.). RESULTS: The synthetic sequence required seven steps: protection of the hydroxyl groups of D ‐mannitol, diol oxidative cleavage with sodium metaperiodate, alkene formation by Wittig reaction with methoxycarbonylmethylidene(triphenyl)phosphorane, cyclopropanation, acetal hydrolysis with perchloric acid and oxidative cleavage with sodium metaperiodate gave methyl (1S, 3S)‐3‐formyl‐2,2‐dimethylcyclopropane‐1‐carboxylate. The final step comprised reaction of the aldehyde with five different aromatic phosphorus ylides to give the pyrethroids. CONCLUSION: An efficient and versatile synthesis of ten new pyrethroid methyl esters has been accomplished from the readily available D ‐mannitol in seven steps. All compounds showed insecticidal activity, and methyl (1S, 3S)‐3‐[(Z)‐2‐(4‐chlorophenyl)vinyl]‐2,2‐dimethylcyclopropane‐1‐carboxylate was the most active, killing 90% of A. monuste orseis and 100% of T. absoluta and P. americana. Copyright © 2009 Society of Chemical Industry 相似文献
128.
Marta Borobia Marcelo De las Heras Javier Godino Luis M. Ferrer Delia Lacasta Araceli Loste Juan J. Ramos Aurora Ortín 《Journal of veterinary diagnostic investigation》2022,34(1):112
Jaagsiekte sheep retrovirus (JSRV) causes ovine pulmonary adenocarcinoma. JSRV can be transmitted via infected colostrum or milk, which contain somatic cells (SCs) harboring JSRV provirus. Nevertheless, the cell types involved in this form of transmission and the involvement of the mammary gland remain unknown. We separated adherent cells (macrophages and monocytes) by plastic adherence, and lymphocytes (CD4+ and CD8+ T cells, and B cells) by flow cytometry, from SCs in milk samples from 12 naturally infected, PCR blood test JSRV–positive, subclinical ewes. These cell populations were tested by PCR to detect JSRV provirus. The ewes were euthanized, and mammary gland samples were analyzed immunohistochemically to detect JSRV surface protein. We did not detect JSRV provirus in any milk lymphocyte population, but milk adherent cells were positive in 3 of 12 sheep, suggesting a potential major role of this population in the lactogenic transmission of JSRV. Immunohistochemistry did not reveal positive results in mammary epithelial cells, pointing to a lack of participation of the mammary gland in the biological cycle of JSRV and reducing the probability of excretion of free viral particles in colostrum or milk. 相似文献
129.
A sandwich enzyme-linked immunosorbent assay for the detection of Streptococcus suis. 总被引:4,自引:0,他引:4 下载免费PDF全文
B Serhir R Higgins D Dubreuil M Gottschalk R Lallier 《Canadian journal of veterinary research》1993,57(1):19-24
A double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the detection and the identification of Streptococcus suis capsular types 1, 2, 1/2, 3 and 22. The specificity of this test was first evaluated using reference strains of S. suis capsular types 1 to 28 and 1/2 as well as 15 different bacterial species susceptible to be isolated from swine. The ELISA developed was very specific for capsular types 1, 3 and 22 but it could not discriminate between capsular types 2 and 1/2. In a second study, S. suis isolates from 328, 493, 368 and 76 diseased pigs were used to detect capsular types 1, 2 or 1/2, 3 and 22 respectively. The relative specificity and sensitivity varied between 98% and 100%. The ELISA results were in excellent agreement with the standard techniques (biochemical tests, coagglutination and capsular reaction tests) in detecting both positive and negative strains. Kappa values were 0.80, 0.99, 0.97 and 1.00 for detecting S. suis capsular types 1, 2 or 1/2, 3, and 22 respectively. To evaluate the relative-sensitivity of the test, primary cultures from 73 diseased pigs and tissue samples from 67 diseased pigs were used directly for detecting these capsular types. With primary cultures, the relative specificity and sensitivity (95.9% and 91.6% respectively) remained high and the test was very suitable (Kappa = 0.87). The ELISA using tissue samples gave a good specificity (97.6%), a moderate sensitivity (62.5%) and a low agreement with standard tests (Kappa = 0.64).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
130.
Eliana Guedes Stehling Tatiana Amabile Campos Marcelo Brocchi Vasco Ariston de Carvalho Azevedo Wanderley Dias da Silveira 《Journal of veterinary science (Suw?n-si, Korea)》2008,9(1):75-83
An Escherichia coli strain (SEPT13) isolated from the liver of a hen presenting clinical signs of septicaemia had a LD50 of 4.0 × 105 CFU/ml in one-day-old chickens, expressed Ia, Ib, E1, E3, K and B colicins and aerobactin. The strain was ampicillin and streptomycin resistant, and found to have fimA, csgA and tsh DNA related sequences; it could adhere to and invade HEp-2 and tracheal epithelial cells, expressed fimbriae (observed by electron microscopy), and had five plasmids of 2.7, 4.7, 43, 56, and 88 MDa. Transposon mutagenesis of strain SEPT13, with transposon TnphoA, resulted in a mutant strain named ST16 that had a LD50 of 1.2 × 1012 CFU/ml. All other biological characteristics of strain ST16 were the same as those detected for strain SEPT13 except for the migration of an 88 MDa plasmid to the 93 MDa position indicating the insertion of the transposon into the 88 MDa plasmid. The 93 MDa plasmid of strain ST16 was transferred, by electroporation assay, to non-pathogenic receptor strains (E. coli strains K12 MS101 and HB101), resulting in transformant strains A and B, respectively. These strains exhibited adhesion properties to in vitro cultivated HEp-2 cells but did not have the capacity for invasion. The adherence occurred despite the absence of fimbriae; this finding suggests that the 88 MDa plasmid has afimbrial adhesin genes. 相似文献