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991.
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994.
Effect of two species of cyanobacteria as biofertilizers on some metabolic activities, growth, and yield of pea plant 总被引:1,自引:0,他引:1
Mohamed Elanwar H. Osman Mostafa M. El-Sheekh Amal H. El-Naggar Saly F. Gheda 《Biology and Fertility of Soils》2010,46(8):861-875
Two cyanobacterial species (Nostoc entophytum and Oscillatoria angustissima) were tested as biofertilizers, substituting the normally used chemical fertilizer, for pea plant. Inoculation of soil with a suspension of each species or a combination of the two species significantly increased the germination percentage and stimulated the other measured growth parameters and photosynthetic pigment fractions of pea. However, the soil inoculation with one cyanobacterial species and the addition of the recommended dose or half the recommended dose of chemical fertilizer were usually more effective and also increased carbohydrate and protein contents of produced pea seeds. However, biofertilization combined with half the recommended dose of the chemical fertilizer was usually more effective than the addition of the full rate of the chemical fertilizer, and this may allow saving 50% of the used chemical fertilizer. The protein profile of the produced seeds showed appearance and disappearance of some protein bands in response to fertilization treatments compared to the control. Blue green algae analyses show that N. entophytum fixed more N, produced more exopolysaccharide, and contained more auxin and cytokinin than O. angustissima, the latter contained more gibberellins. These data may explain their different influences on growth and yield of pea. 相似文献
995.
K. M. Vlassak F. Mercante R. Straliotto A. Franco M. Vuylsteke J. Vanderleyden 《Biology and Fertility of Soils》1997,24(3):274-282
Inoculation of beans (Phaseolus vulgaris L.) with strains of R. tropici IIB and R. etli resulted in the disappearance of the R. tropici IIB stains from the nodule population and their replacement by other (non R. tropici IIB) bean symbionts (Vlassak et al. 1996). Coinoculation studies in monoxenic conditions and in soil core microcosms with
plants harvested at two different growth stages indicated that the inoculated R. tropici IIB strains CIAT899 and F98.5 possess a good intrinsic competitiveness which declines, however, at a later plant growth stage
and in soil conditions. The poor saprophytic competence of R. tropici IIB strain CIAT899 was further demonstrated by its poor survival in soil core microcosms after bean harvest. Strains were
isolated from the field plots with a 3-year bean-planting history, characterized and evaluated for their competitiveness against
R. tropici IIB strain CIAT899. Isolates from field plots, which had been repeatedly inoculated with R. tropici IIB strain CIAT899, showed a higher nodule occupancy compared to R. tropici IIB strain CIAT899, and this higher competitiveness exhibited by the field isolates might be an additional reason for the
poor performance of R. tropici IIB strain CIAT899 in the field study. Plots with and without a history of bean production revealed after 3-year bean cultivation
an almost totally different population that also significantly differed in competitiveness.
Received: 12 February 1996 相似文献
996.
Genetic analysis of resistance of wheat seedlings to two races of Puccinia striiformis was conducted on F1 , F2 and F3 generations from crosses Carstens V (CV) × Lee, Spaldings Prolific (SPA) × Lee and CV × SPA. F2 generations from crosses of CV and SPA with Strubes Dickkopf (SD) were also studied. The plants were classified into six resistance classes and analysed by factorial correspondence analysis and nonhierarchical classification. The two P. striiformis isolates tested were a French isolate of race 43E138 and a Lebanese isolate of race 2E16, selected for the differences in their virulence spectra for the common differential cultivars Strubes Dickkopf and Nord Desprez. Resistance of CV and SPA was recessive and dominant to races 43E138 and 2E16, respectively. CV possessed three or four resistance genes, one of them being expressed with both races. Two genes of CV had a cumulative effect for resistance to 43E138 and two or three gave dominant resistance to 2E16. SPA had three resistance genes, all of which gave resistance to 2E16 and two of which also gave resistance to 43E138. SPA had one gene in common with CV for resistance to both races. Furthermore, the gene for resistance to race 2E16 in CV and SPA was allelic with a gene in SD, and was probably Yr25 . 相似文献
997.
Rachel E. Creamer Pat Bellamy Helaina I. J. Black Clare M. Cameron Colin D. Campbell Paul Chamberlain Jim Harris Nisha Parekh Mark Pawlett Jan Poskitt Dote Stone Karl Ritz 《Biology and Fertility of Soils》2009,45(6):623-633
The use of indicators in soil monitoring schemes to detect changes in soil quality is receiving increased attention, particularly
the application of soil biological methods. However, to date, the ability to compare information from different laboratories
applying soil microbiological techniques in broad-scale monitoring has rarely been taken into account. This study aimed to
assess the consistency and repeatability of two techniques that are being evaluated for use as microbiological indicators
of soil quality: multi-enzyme activity assay and multiple substrate-induced respiration (MSIR). Data were tested for intrinsic
(within-assay plate) variation, inter-laboratory repeatability (geometric mean regression and correlation coefficient) and
land-use discrimination (principal components analysis). Intrinsic variation was large for both assays suggesting that high
replicate numbers are required. Inter-laboratory repeatability showed diverging patterns for the enzyme assay and MSIR. Discrimination
of soils was significant for both techniques with relatively consistent patterns; however, combined laboratory discrimination
analyses for each technique showed inconsistent correspondence between the laboratories. These issues could be addressed through
the adoption of reliable analytical standards for biological methods along with adequate replication. However, until the former
is addressed, dispersed analyses are not currently advisable for monitoring schemes. 相似文献
998.
999.
1. Two experiments were conducted with 1056 1-d-old Cobb x Cobb feather-sexed broiler chicks, to determine the relative nicotinic acid biopotencies of nicotinic acid (NA) and nicotinamide (NAm). 2. Two methods were used: the slope-ratio technique and the broken-line model. 3. In experiment 1, using the slope-ratio technique, NAm was 0.82 as active as NA in promoting growth to 21 d of age. In experiment 2 NAm was 0.96 as bipotent as NA. 4. Applying the broken-line model to the body weight data at 21 d of age for both NA and NAm in experiment 1, it was found that NAm had approximately 0.82 NA activity. The same analysis applied to the data of experiment 2 indicated that the biopotency of NAm was 1.09. 5. A t-test of the slope-ratio values obtained in both experiments indicated that the average (0.89) was not significantly different from 1.0. 6. It was concluded that the relative biopotencies of NA and NAm in broiler chicks fed a maize-soyabean meal diet were similar. 相似文献
1000.
A. Akramkhanov R. Sommer C. Martius J. M. H. Hendrickx P. L. G. Vlek 《Irrigation and Drainage Systems》2008,22(1):115-126
In Khorezm, a district of Uzbekistan situated in the Aral Sea Basin, soil salinization is an important driver of soil degradation
in irrigated agriculture. The main objective of this study was to identify techniques that enable rapid estimation of soil
salinity. Therefore, bulk electrical conductivity of the soil (ECa-meas) was measured with three different devices (2P, 4P, and CM-138) and electrical conductivity of the soil paste (ECp-meas) was measured with the so-called 2XP device. These measurements were compared with independent estimates of ECa-calc and ECp-calc based on laboratory measurements of the saturated extract, ECe, of soil samples from the same sites. Soil salinity could be assessed satisfactorily with all four devices. ECp-meas could be well reproduced by the 2XP device (R
2 = 0.76), whereas ECa-meas estimates using 2P, 4P, and CM-138 in the field were less accurate (R
2 < 0.50). The sensitivity of all devices to the main ions Cl− and Ca2 + suggests that the measuring principles are similar for all instruments. The devices can therefore be used interchangeably.
Field assessment of soil salinity was considerably enhanced by the use of CM-138, because large areas can be quickly assessed,
which may be desirable in spite of the lower accuracy. 相似文献