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81.
An investigation was made of the action of the juvenile hormone analogues (JHAs) methoprene (ZR-515) and 3-[5-(4-ethylphenoxy)-3-methylpent-3-enyl]-2, 2-dimethyloxirane (R-20458), and the insecticides chlorpyrifos and methomyl, when applied, separately or in combination, to the late insect stages of susceptible (S) and aminocarb-resistant (Rm) strains of Spodoptera littoralis Boisd. Sixth-instar larvae of the Rm strain showed detectable levels of cross-resistance to chlorpyrifos, methomyl and R-20458. However, cross-resistance to methoprene was less pronounced in the Rm strain. Treatment of the same instar with the ED50 of methoprene produced an appreciable level of sterility in the S strain, but this level decreased in the Rm strain. Similar treatment with R-20458 caused a lower level of sterility in the S strain and the Rm strain was less affected. In the S strain, the ED25 of either chlorpyrifos or methomyl when applied simultaneously with the ED25 of R-20458, produced an antagonistic effect and the Rm strain was more capable of resisting the joint action of these compounds. The treatment, ED25 chlorpyrifos + ED25 methoprene produced an additive effect on the S strain, while the Rm strain tolerated their combined action. Nevertheless, the treatment, ED25 methomyl + ED25 methoprene produced additive effects on both the S and Rm strains. The prepupae of the Rm strain tolerated the action of the insecticides methomyl and chlorpyrifos. A similar pattern of cross-resistance was also detected against the action of the two hormones at the ED25 level, while at the ED25 level, both the S and Rm strains were almost equally sensitive to the action of the two juvenoids. Chlorpyrifos-JHA combinations produced additive effects on prepupae of the S strain while the Rm strain completely resisted their joint action. Methomyl-JHA combinations produced high potentiation in the S strain, but the Rm strain remained insensitive to their joint action. Detectable levels of tolerance to the action of chlorpyrifos and methomyl at the ED25 and ED50 levels were indicated in 2-day-old pupae of the Rm strain. This was less evident in the case of JHAs, particularly methoprene, which was to some extent equally effective on both strains; the reproductive ability of the S and Rm strains was highly affected by this compound. The pupae of the Rm strains were equally as affected as those of the S strain by the combination ED25 chlorpyrifos+ ED25 R-20458. Nevertheless, the two strains showed antagonism to the action of chlorpyrifos with methoprene. A high level of potentiation was produced in the S strain to the combination of methomyl and R-20458 but the Rm strain was able to withstand their combined action. Of interest in this respect was the action of the combination of methomyl and methoprene, for which high levels of potentiation were detected in pupae of the S and Rm strains. This combination also Produced a high percentage of sterility in mated females of the Rm strain.  相似文献   
82.
Veterinary Research Communications - Industrial chemical solutions are widely used as a method to disinfection of aquaculture water and environments. The aim of the present study was to evaluate...  相似文献   
83.
Chu  Demiao  Yao  Tao  Zhou  Liang  Yan  Hanwei  Yu  Min  Liu  Yamei  You  Yunfei  Bahmani  Mohsen  Lu  Changqing  Ding  Zhenhao  Liu  Shengquan 《European Journal of Forest Research》2022,141(1):59-69

This work focuses on the genetic variation of Chinese fir clones in the radial direction. Four 20-year-old Chinese fir clones were selected in Kaihua Forest Farm, Zhejiang, China, and the differences and genetic characteristics were studied. Clonal repeatability, genotype coefficient of variable, and phenotypical coefficient of variable were calculated to light on the genetic variation on the radial direction. Results showed significant differences (P?<?0.05) between the clones and annual rings of the same clone. The clonal repeatability of the ten wood properties is ranged from 0.5 to 0.8, wherein the fiber length, elastic modulus, and total dry density are higher than 0.7. For all the measured traits, the phenotypic variation of clones is greater than that of the genetic variation. Overall, the measured wood traits, especially the mechanical and physical properties, are strongly controlled by heredity, which means they are potentially helpful for genetic improvement of wood properties and optimal breeding. Furthermore, the clonal repeatability of the measured traits varies between annual rings, and the physical and mechanical properties are relatively stable. The principal component analysis results reveal that the clone of Kai 13 has the highest score.

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84.
In this paper, laccase enzyme was immobilized onto zinc ferrite nanoparticle and the characteristics of enzyme immobilized nanoparticle (EIN) were evaluated by Fourier transform infrared (FTIR) and scanning electronic microscope (SEM). Enzymatic decolorization of dyes using EIN from single and binary systems was studied. Direct red 31 (DR31) and Acid blue 92 (AB92) were used as model dyes. The effects of several parameters such as EIN dosage, pH, and dye concentration on decolorization of dyes from single and binary systems were evaluated. The optimized amount of EIN, reaction time, and pH for decolorization of dyes from single and binary systems were 0.2 g (for DR31) and 0.3 g (for AB92), 40 min, and 3 in single systems and 0.2 g (for DR31 and AB92), 40 min, and 3 in binary systems, respectively. Dye decolorization kinetics followed Michaelis-Menten model. The results showed that enzymatic process using EIN was effective method to decolorize dyes from single and binary systems.  相似文献   
85.
The objectives of this study were to determine the effects of nitrogen (N) forms and deficient and toxic rates of boron (B) on the growth, NO3 accumulation, membrane permeability, mineral nutrition, and nitrogen use efficiency (NUE) of bunch onion (Allium cepa L. var. Radar) plants. Therefore, 20% of NO3 in reference nutrient solution was replaced by NH4, urea, or mixed amino acids (AA). To each of these solutions 3, 30, or 300 mmol m?3 B was added. Fresh and dry weights were the same in the reference and mixed AA treatments, but NH4 and urea decreased these growth parameters as compared to the reference. Mixed AA decreased the NO3-N content while urea increased it, and NH4 treatment yielded similar NO3-N content as compared to the reference. The nitrogen content of plants was increased by NO3 replacement with either NH4 and, urea or mixed AA. At the 300 mmol m?3 B rate, B content of plants was decreased by NH4 and urea, but increased by the mixed AA treatment. Membrane permeability was increased by NH4?replacement of NO3. Nitrogen use efficiency was found the highest in the reference treatment. Nitrogen and NO3-N contents were increased by the 300 mmol m?3 B rate. Increasing B in nutrient solution increased the B contents of plants. Mixed AA treatment decreased the phosphorus (P) content of plants. Potassium (K) and chloride (Cl) contents of plants were decreased in the NH4 treatment where B was applied at the 3 mmol m?3 rate. These results suggest that bunch onion growers may reduce NO3 content in onion tops by partially replacing NO3 with amino acids without reducing yield.  相似文献   
86.
87.
This study was undertaken to compare patterns of agronomic characters and yellow pigment content diversity between Iranian durum landraces and modern varieties. In four field experiments, a collection of 127 accessions of landraces and 23 modern cultivars tetraploid wheat representing Iranian and global genetic diversity were tested under optimum and rain-fed conditions. Across the environments, the yellow pigment concentrations ranged from 1.85 mg kg?1 to 8.95 mg kg?1 in the field-grown samples. Multivariate analysis detected five groups, four including landraces and one comprising modern cultivars. As a group, modern cultivars were the most productive and showed high mean values for harvest index, grains per spike and yellow pigment, but they had the lowest plant height. Landraces had the highest mean number of spikes per m2 and 1000-kernel weight, but were characterized by low plant height and yellow pigment content. Clustering analysis also showed that, based on yield and yellow pigment content, the accessions in different groups were of different origins, suggesting that there was no clear relationship between accessions and geographical diversity. According to our results, Iranian landraces can be particularly useful as germplasm in breeding programmes to improve spikes per m2 and 1000-kernel weights.  相似文献   
88.
The aim of this study was to survey long-term changes in phosphorus (P) fractions in soils in different land uses. Sequential extraction had been used to determine soil P fractionation on the basis of land-use change, i.e. native forest to vineyard and wetland to both alfalfa and wheat at the end of 30 and 20 years, respectively. The highest values of labile-P (L-P) fractions in surface soil layers were observed in the cultivated land. The calcium-bound P was the most affected fraction by land-use change with the lowest amount in the vineyard and the highest amount in the alfalfa land. Conversion of forest to vineyards causes P in the soils to be more vulnerable to transmission; thus, the least amount of total P (T-P) in vineyard may be attributed to the removal of sediment and sediment bond P from runoff in response to land-use changes. Average L-P in alfalfa land was two times more than that in vineyard. Results showed that 44.5% of T-P in native land was stored in surface layer; besides, the portion of the arable surface horizon in T-P sequestration was 33%.  相似文献   
89.
Soil organic matter and its components play a key role in the stabilization of soil aggregates. This study aimed to investigate the distribution of organic carbon (OC), total nitrogen (TN), hot-water extractable (HWE) and dilute acid extractable (DAE) carbohydrates and CaCO3 in water-stable aggregates in histosols of Shahrekord, Iran. Additionally, correlations between aggregate stability (mean weight diameter (MWD) values) and mentioned characters were also examined. Results showed that at all depths in all 18 profiles, larger aggregates contained more OC, TN and carbohydrate content than the smaller aggregates, whilst CaCO3 had the opposite trend. OC, TN and carbohydrate fractions followed a consistent similar trend by aggregate size. The positive correlation between OC and TN within the aggregates was considerable. OC, TN, carbohydrate fractions and MWD significantly (P < 0.01) decreased with depth. Average concentration of CaCO3 was almost the same in aggregates <4 mm at all depths. We observed very low values of ratios HWE:OC and DAE:OC in the study site. OC, TN and carbohydrate fractions each gave highly or very highly significant correlations with aggregate stability. We obtained significant, but weak negative correlation of CaCO3 with aggregate stability (P = 0.05; r = ?0.23), implying that CaCO3 is a disaggregating agent in these histosols.  相似文献   
90.
Plant growth-promoting fungi (PGPF) such as Phoma sp. (isolates GS8-1, GS8-2 and GS8-3) and non-sporulating fungus (isolate GU21-2) were tested for their ability to induce systemic resistance against Colletotrichum orbiculare in cucumber. These isolates, used as colonized barley kernels to natural soils, induced systemic resistance in the greenhouse as well as in the field. Different elicitors from PGPF such as cell walls retaining or lacking protein and lipids, cell walls lipid fraction, and three fractions of culture filtrate (CF) with different molecular weight ranges were tested for their ability to elicit the defense response of cucumber plants under controlled conditions. Cell wall fraction lacking protein and lipids and the cell wall lipid fraction from root colonizing isolates GS8-1, GS8-2, and GS8-3 protected plants against C. orbiculare. While, only cell wall lipid fraction and CF fractions of different molecular weight ranges of the isolate GU21-2 protected plants against C. orbiculare infection. Methanol-soluble substances from CF fractions with molecular weight greater than 12,000 and less than 8000 consistently protected plants against the pathogen. Germination of C. orbiculare spores decreased significantly at 72 h of incubation on leaves of PGPF-protected plants. Isolate GU21-2 was the most effective in inhibiting spore germination. On the other hand, isolates GS8-1 and GU21-2 induced lignifications in the hypocotyls of seven-day-old cucumber seedlings after challenge inoculation with C. orbiculare. Three-week-old cucumber plants treated with isolate GU21-2 and challenged with C. orbiculare showed increased activities of exo- and endo-forms of glucanase and chitinase, as well as peroxidase and polyphenol oxidase in the second true leaves. Induction treatment with isolate GS8-1 also increased the activities of these enzymes with the exception of exo-glucanase. This study shows that the inoculation of PGPF or its CF resulted in additive effect on the suppression of anthracnose disease in cucumber.  相似文献   
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