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191.
A series of available phosphorus (Olsen) levels ranging from 10 to 40 ppm were achieved in a semi-arid soil. The influence of the levels of phosphorus on the symbiotic interaction between two subtropical tree species, Acacia nilotica and Albizzia lebbeck, and a mixed inoculum of indigenous arbuscular mycorrhizal (AM) fungi was evaluated in a greenhouse study. The extent to which the plant species depended on AM fungi for dry matter production decreased as the levels of soil P increased, but the degree of this decrease differed in the two species tested. Acacia nilotica colonized by AM fungi showed a significant increase in shoot P and dry matter at a soil P level of 10 ppm whereas in Albizzia lebbeck, such increase occurred at 20 ppm. Mycorrhizal inoculation response disappeared beyond soil P levels of 25 ppm in Acacia nilotica and 30 ppm in Albizzia lebbeck. Levels of soil P greater than 25 ppm suppressed AM fungus colonization in both species. Soil P levels of 30 and 40 ppm and 40 ppm caused negative mycorrhizal dependencies (MD) in Acacia nilotica and Albizzia lebbeck respectively. Values of MD for both species were negatively correlated with soil P levels. Based on the MD values, regression equations were developed to predict MD for given levels of available P. 相似文献
192.
Aritra Bera Paramita Banerjee Sawant Subrata Dasgupta N. K. Chadha Bhawesh T. Sawant Asim Kumar Pal 《Fish physiology and biochemistry》2017,43(6):1677-1688
Diel cyclic hypoxia occurs with varying frequency and duration in freshwater habitats, yet little is known about its effects on reproduction of freshwater fishes. The present study shows that long-term exposure of goldfish (Carassius auratus) to cyclic hypoxia (0.8 ± 0.2 mg/l dissolved oxygen) for 9 h or more, per day, altered plasma lipid and sex steroid profiles, which in turn directly or indirectly suppressed ovarian growth and viable spermatozoa production. Hypoxia decreased total cholesterol and high density lipoprotein (HDL p < 0.05) and elevated triglycerides (TG; p < 0.05) in both sexes. Plasma steroid concentrations particularly of 17α-hydroxyprogesterone (17-HP), estradiol (E2), testosterone (T) in females, and T and 11-ketotestosterone (11-KT) in males were attenuated under diel hypoxic conditions. Intriguingly, both diel and continuous hypoxia elevated plasma E2 and vitellogenin levels in males. However, neither lipid nor steroid profiles recorded any variation in a dose-dependent manner in response to diel hypoxia. The reduced GSI, decreased number of tertiary oocytes, and motile spermatozoa in hypoxic fish clearly indicate suppression of gametogenesis. Thereby, prolonged diel cyclic hypoxia may affect valuable fishery resources and fish population structure by impairing reproductive performances and inducing estrogenic effects in males. 相似文献
193.
Nivedita Sur Srikumar Pal Hemanta Banerjee Narayan Adityachaudhury Anjan Bhattacharyya 《Pest management science》2000,56(3):289-292
The photodegradation of aqueous alcoholic solutions of fenarimol at λ ≥ 250 nm has been examined. UV irradiation of an aqueous methanolic solution for 24 h yielded two photoproducts, identified as 2,4′‐dichlorobenzil and p‐chlorobenzoic acid, while irradiation of a solution in aqueous isopropanol yielded p‐chlorobenzoic acid and two additional products identified as 2,4′‐dichlorobenzophenone and o‐chlorobenzoic acid. A mechanism for the formation of the photoproducts is suggested. © 2000 Society of Chemical Industry 相似文献
194.
Employing four mathematical models (first-order, parabolic-diffusion, Elovich and zero-order), kinetics of potassium desorption from eight soils with and without cropping were studied to evaluate their ability in explaining K release from soils. The decline in the soil test K in cropped soils over original soils was drastic in easily desorbable forms compared to that of strongly held forms like 3 M H2SO4 K. Results showed that parabolic diffusion as well as first-order kinetic equation explained the K release data well for both original and K depleted (cropped) soils. Elovich and zero-order equations were not suitable to describe the kinetic data. However, zero-order equation explained K release data better in case of K-depleted soils as compared to original soils. Soils with higher initial K contents registered higher release rate constants. Over the entire period of cropping the range of release rate (b) decreased from 1.26 to 1.53 × 10?2 to values ranging from 1.12 to 1.30 × 10?2 h?1. In contrast, the first-order equation, parabolic diffusion showed higher b values for cropped soils as they represent the diffusion gradient. Mica and its biotite content in both silt and clay fractions showed significant correlation (r) with b values. Similarly with the rate of K release, clay content of soils maintained significant r whereas the silt content did not. 相似文献
195.
Vikas Kumar N. P. Sahu A. K. Pal Shivendra Kumar Amit Kumar Sinha Jayant Ranjan Kartik Baruah 《Fish physiology and biochemistry》2010,36(3):491-499
A 60-day experiment was conducted to study the effect of dietary gelatinized (G) and non-gelatinized (NG) starch on the key
metabolic enzymes of glycolysis (hexokinase, glucokinase, pyruvate kinase, and lactate dehydrogenase), gluconeogenesis (glucose-6
phosphatase and fructose-1,6 bisphosphatase), protein metabolism (aspartate amino transferase and alanine amino transferase),
and TCA cycle (malate dehydrogenase) in Labeo rohita juveniles. In the analysis, 234 juveniles (2.53 ± 0.04 g) were randomly distributed into six treatment groups each with three
replicates. Six semi-purified diets containing NG and G cornstarch, each at six levels of inclusion (0, 20, 40, 60, 80, and
100) were prepared viz., T1 (100% NG, 0% G starch), T2 (80% NG, 20% G starch), T3 (60% NG, 40% G starch), T4 (40% NG, 60%
G starch), T5 (20% NG, 80% G starch), and T6 (0% NG, 100% G starch). Dietary G:NG starch ratio had a significant (P < 0.05) effect on the glycolytic enzymes, the highest activities were observed in the T6 group and lowest in the T1 group.
On the contrary, the gluconeogenic enzymes, the glucose-6-phosphatase and fructose-1,6 bisphosphatase activities in the organs,
liver and kidney were recorded highest in the T1 group and lowest in the T6 group. The liver aspartate amino transferase activity
showed an increasing trend with the decrease in the dietary G level. However, the muscle aspartate amino transferase activity
was not significantly (P > 0.05) influenced by the type of dietary starch. The alanine amino transferase activity in both liver and muscle showed an
increasing trend with the decrease in the dietary G level. The liver and muscle malate dehydrogenase activities were lowest
in the T6 group and highest in the T1 group. Results suggest that NG (100%) starch diet significantly induced more the enzyme
activities of amino acid metabolism, gluconeogenesis, and TCA cycle, whereas partial or total replacement of raw starch by
gelatinized starch increased the glycolytic enzyme activity. 相似文献
196.
Kateřina Matějíčková Ľubomír Pojezdal Dagmar Pokorová Stanislava Reschová Veronika Piačková Miroslava Palíková Tomáš Veselý Ivana Papežíková 《Journal of fish diseases》2020,43(9):971-978
This work describes the first confirmed cases of carp oedema virus disease (CEVD) in Slovakia and the Czech Republic and the phylogenetic analysis of Czech and Slovak carp oedema virus (CEV) isolates. Four cases of disease outbreak in the Czech Republic are described, the oldest dating from mid-May 2013 and one case from Slovakia dating from May 2019. In all cases, virus presence was confirmed using nested PCR. PCR products were sequenced and compared with 357-bp nucleotide sequences encoding the CEV P4a protein in GenBank. In four cases of disease outbreak (three common carp breeding facilities and one koi garden pond), CEV detected belonged to genogroup I. In one case (koi garden pond), fish were confirmed as infected with CEV from genogroup II. This work complements data on CEV occurrence in European countries and contributes to a better understanding of the pathways leading to transmission of the virus throughout Europe. 相似文献
197.
José Ruiz Hidalgo Melina Santillán Eduardo Alberto Parellada Priyanka Khyaliya Adriana Neske 《国际虫害防治杂志》2020,66(2):116-121
AbstractThis is the first report on the antifeedant, toxic and nutritional effects produced by the synthetic chalcones on the lepidopteran Spodoptera frugiperda followed by structure-activity relationship. Bis (5a-c) and mono (8a-d) chalcones have been synthesized via Claisen-Schmidt condensation and have been purified and characterized. The mono chalcones 8b and 8d displayed toxic effects on early larval instars when incorporated to the larval diet at 100?µg per g of diet (40 and 60%, respectively) and low adults emergency with malformations leading to death. The remaining chalcones 8a, 8c, 5a, 5b and 5c do not displayed toxic effects at the same dose. The evaluation of nutritional indices indicated that 8a and 8c were the only tested chalcones to produce decrease in the growth rate and to reduce the efficiency with which larvae converted ingested food into biomass. 相似文献
198.
Dávid U. Nagy Emily S. J. Rauschert Tamás Henn Kevin Cianfaglione Szilvia Stranczinger Robert W. Pal 《Weed Research》2020,60(3):232-240
Developing invasive plant management strategies is an important task in modern ecology, conservation biology and land management. Solidago gigantea is considered a problematic invader in Europe and Asia, where it forms dominant stands that can decrease species diversity. There is, therefore, an urgent need for effective management to reduce S. gigantea infestations and their negative impacts. We examined the efficacy of multiple approaches to S. gigantea management in Hungary. In our study, we evaluated the effect of several long-term management techniques such as grazing, mowing and periodic flooding on the invader's density as well as native community diversity. In addition, we investigated the short- and long-term effects of mowing combined with other treatment options, to estimate the influence of increased management intensity. Our results indicate that all tested management techniques had negative impacts on S. gigantea density. Short-term mowing did not appear to improve species diversity in the resident community; however, all long-term options improved species diversity. Moreover, combining treatments with mowing varied in its effectiveness; mowing once increased the efficacy of flooding, but decreased the efficacy of grazing, while mowing twice decreased efficacy of flooding. We suspect this is due to the increased intensity of disturbance, which does not allow for the natural recovery of communities, and after management ceases, invasion is able to re-occur. Our results indicate that for effective management, we need to combine management options which act via different mechanisms, leading to cumulative positive effects on the resident community when applied at moderate levels. 相似文献
199.
This study focuses on the effect of Aegilops longissima on wheat bread making quality. Chromosome 1Sl disomic addition line of Ae. longissima (DAL1Sl) had significantly higher dough strength, grain hardness, mixographic peak height, band width, and unextractable polymeric protein content compared with wheat. DAL1Sl also had additional glutenin and gliadin proteins contributed by Ae. longissima. The larger size of 1Sl coded HMW-GSs sequenced from DAL1Sl and their phylogenetic similarity to the D-genome-coded subunits were suspected to be one of the major reasons for the increased dough strength of DAL1Sl. To transfer the chromosome 1Sl genes responsible for the good bread-making quality to wheat, we generated a chromosome-specific disomic substitution line [DSL1Sl(1A)] by crossing DAL1Sl with nulli 1A tetra 1B genetic stock and further selection. Grain quality analysis revealed significantly lower grain hardness and significantly higher dough strength, farinograph development time, stability time, gluten index, bread loaf volume, and bread quality score in DSL1Sl(1A), compared with wheat. However, the increased bread loaf volume and quality were not proportional to the relatively higher increases in dough strength and gluten index, indicating importance of other traits influencing bread making quality. The presence of a minor hardness locus on chromosome 1A is speculated. 相似文献
200.
T.K. Behera S.S. Dey A.D. Munshi Ambika B. Gaikwad Anand Pal Iqbal Singh 《Scientia Horticulturae》2009,120(1):130-133
Gynoecism has been used on a large scale in heterosis breeding of cucumber. Production of hybrid seeds in bitter gourd is highly expensive because it is done mainly through hand pollination. But utilization of a gynoecious line would be more economical and easier method. Since gynoecious parent has only female flowers, the open pollinated seeds it produces will be F1 hybrid. It will reduce the cost of male flower pinching and hand pollination. Two gynoecious lines, DBGY-201 and DBGY-202 were crossed with two monoecious cultivars, “Pusa Do Mausami” and “Pusa Vishesh” and their F2 populations were observed to determine the inheritance pattern of gynoecious sex form. Another experiment was conducted to determine magnitude of heterosis by utilizing nine inbred lines including one gynoecious line, DBGY-201 in diallel (without reciprocal) mating system. All the gynoecious hybrids showed significant heterosis in a desirable direction for traits like sex ratio (male:female), days to first picking, number of fruits per plant, yield per plant, and vine length. The segregation pattern in F2 suggested that gynoecious sex form in bitter gourd was governed by single recessive gene. The gynoecious hybrids DBGY-201 × “Pusa Vishesh” and DBGY-201 × “Pusa Do Mausami” were important for early harvest (~50 days after sowing) whereas DBGY-201 × “Priya” and DBGY-201 × “Arka Harit” were promising for higher yield. 相似文献