Accumulation of cadmium in growing peanut (Arachis hypogaea L.) seedlings—Its effect on lipid peroxidation and on the antioxidative enzymes catalase and guaiacol peroxidase     

Sunil Kumar  Urmil J. Mehta  Sulekha Hazra 《植物养料与土壤学杂志》2008,171(3):440-447

In plants exposed to high metal concentrations, mechanisms to counteract the oxidative burst are crucial for its survival. To investigate the temporal sequence of physiological reactions of peanut seedlings (Arachis hypogaea L.) to cadmium exposure, seeds were cultured in increasing concentrations of CdCl₂, ranging from 50 to 300 μM. Germination frequency was scored, and the distributions of Cd in root, stem, and leaves were determined after 2 and 4 weeks of culture. Lipid peroxidation and activities of antioxidative enzymes including catalase (CAT; EC 1.11.1.6) and guaiacol peroxidase (GPX; EC 1.11.1.7) were estimated in these three parts of the plant. Germination of seedlings was not affected, but the growth of seedlings was severely suppressed with increasing concentrations of CdCl₂ and incubation period. Pattern of Cd distribution in the three organs varied with concentration and period of exposure to Cd. Increased lipid peroxidation was detected in all parts of the developing seedlings with increasing metal accumulation. Catalase and guaiacol peroxidase activity varied in the three parts of the seedlings with concentration of Cd and incubation period. Guaiacol peroxidase activity appears to be more active in scavenging the reactive oxygen species in developing peanut seedlings. The results of the present experiment demonstrate the advantages of a tissue‐culture model system in studying the complex network of interactions of various factors in stress tolerance.  相似文献   

Nitrogen metabolism and seed composition as influenced by glyphosate application in glyphosate-resistant soybean     

Bellaloui N  Zablotowicz RM  Reddy KN  Abel CA 《Journal of agricultural and food chemistry》2008,56(8):2765-2772

Previous research has demonstrated that glyphosate can affect nitrogen fixation or nitrogen assimilation in soybean. This 2-year field study investigated the effects of glyphosate application of 1.12 and 3.36 kg of ae ha(-1) on nitrogen metabolism and seed composition in glyphosate-resistant (GR) soybean. There was no effect of glyphosate application on nitrogen fixation as measured by acetylene reduction assay, soybean yield, or seed nitrogen content. However, there were significant effects of glyphosate application on nitrogen assimilation, as measured by in vivo nitrate reductase activity (NRA) in leaves, roots, and nodules, especially at high rate. Transiently lower leaf nitrogen or (15)N natural abundance in high glyphosate application soybean supports the inhibition of NRA. With the higher glyphosate application level protein was significantly higher (10.3%) in treated soybean compared to untreated soybean. Inversely, total oil and linolenic acid were lowest at the high glyphosate application rate, but oleic acid was greatest (22%) in treated soybean. These results suggest that nitrate assimilation in GR soybean was more affected than nitrogen fixation by glyphosate application and that glyphosate application may alter nitrogen and carbon metabolism.  相似文献   

Design of Optimum Response Surface Experiments for Electro-Coagulation of Distillery Spent Wash     

R. Krishna Prasad  R. Ram Kumar  S. N. Srivastava 《Water, air, and soil pollution》2008,191(1-4):5-13

Electro-coagulation (EC) of a distillery spent wash has been optimized by Box–Behnken design of surface response analysis in terms of color removal. The design was employed to derive a statistical model for the effect of parameters studied on removal of color using iron anodes. The current density (31 mA/cm²), dilution (17.5%) and time of electrolysis (4 hours) had been found to be the optimum conditions for maximum 95% color removal. The actual color removal at optimized conditions was found to be 93.5% which confirms close to the predicted response using response surface methodology.  相似文献   

Biocontrol potential of Pseudomonas azotoformans,Serratia marcescens and Trichoderma virens against Fusarium wilt of Dalbergia sissoo     

Sabyasachi Banerjee  Seema Singh  Shailesh Pandey  Maneesh S. Bhandari  Amit Pandey  Krishna Giri 《Forest Pathology》2020,50(2)

Wilt disease caused by Fusarium solani is a serious constraint to Dalbergia sissoo (shisham) plantations in northern India. In this study, the antagonistic potential of 40 bacterial isolates recovered from rhizophere soil of healthy shisham trees, and a well‐characterized Trichoderma species (Trichoderma virens) were tested for their possibility as biocontrol agents for F. solani. Two promising isolates (S1 and S15) were identified which inhibited pathogen growth, caused chitin degradation, produced siderophores and solubilized phosphate in vitro. Isolate S15 scored highest for hydrogen cyanide (HCN) production while isolate S1 was a non‐HCN producer. These two isolates were identified as Serratia marcescens (S1) and Pseudomonas azotoformans (S15) following sequence analysis of 16S rDNA. In dual culture assays, T. virens caused 80% inhibition of mycelial growth of the test fungus. The three selected antagonists when tested in planta in the glasshouse completely suppressed production of wilt symptoms on 12‐month‐old shisham plants. Further work is needed to ascertain the potential of these isolates to be used as biocontrol agents to manage shisham wilt under field conditions.  相似文献   

Effects of salinity on growth characteristics and osmoregulation of juvenile cobia,Rachycentron canadum (Linnaeus 1766), reared in potassium‐amended inland saline groundwater     

Jose Antony  Appidi Krishna Reddy  Arun Sudhagar  Hari Krishna Vungurala  Luke A Roy 《Journal of the World Aquaculture Society》2021,52(1):155-170

The suitability of inland saline groundwater as a medium to culture juvenile cobia, Rachycentron canadum, was assessed. In the first experiment, juvenile cobia stocked in raw (unamended) saline groundwater at salinities of 5, 10, and 15 g/L exhibited complete mortality after 108, 176, and 195 hr, respectively. The second experiment evaluated the rearing of juvenile cobia (mean weight ~9.23 ± 0.12 g) in potassium (K⁺)‐amended saline groundwater (100% K⁺ fortified) and reconstituted seawater at salinities of 5, 10, and 15 g/L to assess growth and osmoregulation in distinct culture media. Following 60 days of culture, all fish survived the experimental period. Final mean bodyweight of cobia reared in K⁺‐amended saline groundwater (103.2–115.8 g) and seawater (111.2–113.8 g) of different salinities did not vary significantly (p > .05). No differences (p > .05) were observed in specific growth rate, weight gain (%), and feed conversion ratio between treatment groups. Serum osmolality increased with salinity and was significantly higher (p < .05) for fish in K⁺‐amended saline groundwater (353–361 mOsmol/Kg) than in reconstituted seawater (319–332 mOsmol/Kg), although differences were not observed between salinities by water type. Cobia stocked in saline groundwater of different salinities were osmoregulating normally, and the higher values observed may be because of variations in ionic composition and other interfering ions in saline groundwater. Trial results suggest that juvenile cobia can achieve optimal growth in K⁺‐amended saline groundwater of low and intermediate salinities.  相似文献   

Adoption and Impact of Modern Rice Varieties on Poverty in Eastern India     

Kwasi Bannor Richard  Amarnath Krishna Kumar Gupta  Oppong-Kyeremeh Helena  Abawiera Wongnaa Camillus 《水稻科学》2020,27(1):56-66

The factors affecting the adoption of modern varieties(MVs) of rice and impact on poverty in Odisha, India were discussed. A total of 363 households from Cuttack and Sambalpur districts of Odisha via multistage sampling technique participated in the survey. The Cragg's Double hurdle model was used to model the determinants of adoption and intensity of adoption of MVs of rice, and the propensity score matching was used to analyze the impact of adoption on poverty. The results showed that age, education, risk aversion, land size, yield, perception of MVs as high yielding, resistant to diseases and availability of MVs positively influenced the decision to adopt. However, variables such as household size, experience of a farmer, off-farm job participation, amount of credit received, cost of seeds, insecticides and fertilizers negatively influenced the adoption of MVs. Intensity of adoption of MVs was negatively influenced by experience of a farmer, cost of fertilizer and marketability of MVs, and positively affected by household size, risk aversion, land size, cost of insecticides, perception of MVs as high yielding and availability of MV seeds. Poverty incidence, gap and severity were high among non-adopters to adopters of MVs. After matching adopters and non-adopters of MV groups using four different algorithms of nearest neighbour matching, stratification matching, radius matching and kernel matching, the impact of MV adoption resulted in higher per capita monthly household expenditure by about US$ 52.82 to US$ 63.17.  相似文献   

Mango explant browning: Effect of ontogenic age,mycorrhization and pre-treatments     

Hare Krishna  R.K. Sairam  S.K. Singh  V.B. Patel  R.R. Sharma  Minakshi Grover  Lata Nain  A. Sachdev 《Scientia Horticulturae》2008

The in vitro performance of mango shoot culture is delimited by several factors, of which explant necrosis and media browning are considered as major constraints for successful exploitation of such an important commercial crop. Our results showed that source of explants had a significant effect on the performance of in vitro cultures of mango. The variations in survival of explants collected from glasshouse grown seedlings and field-grown stock plants indicated towards differences between their physiological/ontogenic age. Though, chronologically, both are young, the glasshouse grown shoots are ontogenetically younger and; therefore, responded better over field-grown shoots. Improved performance of explants harvested from mycorrhizal plants suggests integration of mycorrhizal biotechnology with tissue culture biotechnology in order to achieve better results as mycorrhiza being a well-known stress alleviator may help explants mitigate in vitro stresses. Furthermore, shoot tip explants of field-grown ‘Amrapali’ mango was assayed for their browning propensity at pre- and post-culture stages. Status of different bio-chemicals such as in vivo phenol, in vitro phenol exudation, phenylalanine ammonia lyase, peroxidase and polyphenol oxidase as affected by various pre-treatments were estimated to establish the relationship of these bio-chemicals with necrosis of mango shoot cultures. The different pre-treatments comprised etiolation of newly emerged shoots (5–7 days old) of stock plants using black polythene for 7 days, etiolation treatment + agitation of explants in antioxidant solution (antioxidants: ascorbic acid at 100 mg l⁻¹ + citric acid at 50 mg l⁻¹), etiolation treatment + agitation of explants in polyvinylpyrrolidone solution (PVP) at 0.2% and non-etiolated control. Of these, explants treated with PVP proved to be superior to other treatments with regards to explant necrosis percentage as such explants exhibited least activities of phenols and oxidative enzymes. Correlation studies indicated existence of high positive correlation between explant necrosis and these bio-chemicals.  相似文献   

Genetics of five hairy phenotypes and a linkage group of Pennisetum americanum     

M. Krishna Rao  Prasad R. K. Koduru 《Euphytica》1979,28(2):445-451

Summary In pearl millet hairy lamina, hairy sheath and hairy stem were inherited as monofactorial recessives while hairy leaf margin and hairy node were inherited as monogenic dominant traits. The gene for hairy lamina hl showed independent assortment from the gene for hairy node, Hn, and showed linkage with the genes hst (hairy stem), hs (hairy sheath) and Hm (hairy leaf margin). Furthermore, Hl was observed to have an epistatic effect on the expression of hs. The percentages of recombination between the gene pairs hl-hst, hl-hs and hl-Hm were 0.0, 8.30±0.44 and 19.81±0.98 respectively. Thus the genes hl-hst-hs Hm form one linkage group.  相似文献   

Should I stay or should I go? Fishers’ ability and willingness to adapt to environmental change in Cambodia's Tonle Sap Lake     

Krishna Bahadur KC  Ratha Seng  Evan Fraser 《Fisheries Management and Ecology》2019,26(3):211-223

The livelihoods of people dependent on the Tonle Sap floodplain ecosystem in Cambodia are expected to be affected by changes in economic conditions, social circumstances, environmental perturbations, demographic shifts and political climates. This study assesses how small‐scale fisheries’ livelihoods are changing in response to social and environmental conditions using the opinions of fishers collected through an intensive family survey of 514 households from Pursat and Battambang Provinces in Cambodia. Probit modelling approach was used to assess whether a fisher would continue fishing or not in the future when subjected to a variety of shifting conditions and identify the factors associated with their response. It was found that in any future condition about 50% of fishers would likely continue to fish, which suggests how much they love their traditional livelihood of fishing. The remaining 50% considered to diversify their livelihood strategy by shifting towards a combination of fishing, farming, and off‐farm jobs. Furthermore, the analysis found that the fishers will change their fishing practices depending on how other sectors in the region develop. The model showed increasing access to agricultural activities decreased the likelihood of continuing to fish, whereas finding an off‐farm job corresponded to increased likelihood of continuing to fish.  相似文献   

Resistance of pearlspot larvae,Etroplus suratensis,to redspotted grouper nervous necrosis virus by immersion challenge     

Makesh Marappan  Aathithya Rengarajan  Venkata Satyanarayana Nallala  Krishna Sukumaran  Aritra Bera  Thirugnamurty Sivaramakrishnan  Govindarajan Thiagarajan  Muniyandi Kailasam  Vijayan Koyadan Kizhakedath 《Journal of fish diseases》2019,42(2):249-256

Viral nervous necrosis (VNN) affects more than 120 species mostly belonging to the order Perciformes. However, none of the brackishwater species belonging to the family Cichlidae under the order Perciformes are reported to be susceptible. Hence, the present experiment was undertaken to study the susceptibility of the brackishwater cichlid, pearlspot, Etroplus suratensis to NNV. Thirty‐day‐old pearlspot larvae were infected with NNV by immersion. Mortality was recorded till 14 days post‐infection, and the infected larvae were subjected to nested RT‐PCR and histology. The virus was isolated from infected larvae using SSN‐1 cells. To study the replication of the virus in vitro, primary cultured brain cells of E. suratensis and IEK cells were infected with NNV. No mortality was observed in any of the control or experimentally infected larvae. However, the experimentally infected larvae were positive for NNV by nested RT‐PCR and the virus was isolated using SSN‐1 cells. Further, the infected pearlspot brain cells and IEK cells showed cytopathic effect at second and third passage of the virus and they were positive for NNV by nested RT‐PCR. Pearlspot is relatively resistant to VNN although the virus could replicate in the larvae and in cell culture.  相似文献