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31.
In sweet potato tuber, which is a tropical plant, long‐term storage leads to loss of water and carbohydrate, thus water mobility was investigated using 1H‐NMR spectroscopy. Electrolyte leakage indicated that tubers stored at 15 °C for 1 year were partly injured and that frozen‐thawed tissues were dead. Nuclear magnetic resonance (NMR) spin–lattice relaxation time (T1) and spin–spin relaxation time (T2) clearly increased with the duration of storage, whereas these values decreased in the dead tissues. Furthermore, Arrhenius plots for T1 and T2 were determined at temperatures ranging from 20 to 0 °C in 2.5 °C steps. In the fresh tubers, a strong converse temperature dependency was shown in the T2 measurement. On the contrary, there was no temperature dependency in the T2 of the dead tissues. Thus, the existence of inverse temperature dependency reflected tissue viability. Additionally, any change in the T2 of the fresh tubers occurred at about 14 °C, which virtually coincided with the storage temperature of 15 °C. The slope change in T2 might have responded to a physiological change as a primary event. In conclusion, monitoring water status by NMR could provide early identification of changes in the quality of post‐harvest crops; this method shows great promise for use in environmental‐stressed crop yield research.  相似文献   
32.
Grape seeds accumulate in huge quantities as byproduct during wine production and are therefore a cheap source for pharmacologically active agents. However, studies prove poor antibacterial activity, and results of analyses are sometimes contradictory. The aim of this study was, thus, to determine the antibacterial activity of grape seed extracts with special focus on the chromatographic characterization of active fractions. In the course of these investigations, extraction protocols were optimized so that microwave-assisted extraction (MAE) guaranteed highest preconcentration efficiency. Proanthocyanidins, monomeric flavonoid aglycones, as well as some of their glycosides could be identified within yielded extracts via high-performance liquid chromatography-mass spectrometry (HPLC-MS). By that means the coherence number of possible isomers of procyanidins was approximated by a newly developed equation. As far as antibacterial activity determined via screening tests is concerned, the extracts generally have been found to be positively responsive toward 10 different gram-positive and gram-negative bacteria strains. After fractionation of the raw extracts, proanthocyanidins P2, P3, P4 and gallate esters P2G and P3G (P = proanthocyanidin consisting of catechin and epicatechin units, n = oligomerization degree, G = gallate ester) were determined as active antibacterial agents toward 10 different pathogens. Only moderate activity was found for monomeric flavonoid fractions.  相似文献   
33.
Plant growth promoting rhizobacteria (PGPR) promote the plant growth by various direct and indirect mechanisms. The present study was undertaken to isolate and characterise the PGPRs of plum (Prunus domestica) rhizosphere in Pakistan. A total of 95 rhizobacteria were isolated, out of which 40 strains were selected on the basis of morphological, biochemical and Gram staining characteristics. The selected isolates were screened for in vitro plant growth promoting potential and were subsequently evaluated for host plant growth promotion. The selected isolates demonstrated strong lytic enzymatic activities and were able to produce ammonia, siderophore, Hydrogen cyanide along with capability of phosphate solubilisation. Moreover, the results showed a significant growth suppression of pathogenic Fusarium oxysporum and Rhizoctonia solani in an in vitro assay. The plant microbe interaction study was carried out using 11 most efficient rhizobacterial strains inoculated to roots of plum plants. The inoculated PGPRs significantly augmented the leaves number per shoot, shoot diameter, shoot length and plant height. The inoculation also significantly increased the chlorophyll contents of leaves, concentration of micro and macro nutrients compared with control. The current study shows the importance of these selected PGPRs as bio-fertilizer to improve the health and productivity of plum species in Pakistan.  相似文献   
34.
Bioavailability and mobility of lead (Pb) in soils depend upon their partitioning between solution-solid phases and their further fractionation and redistribution among different solid-phase components. However, the dynamics of Pb in salt-affected (saline–sodic) Pb-contaminated (polluted) paddy soil need more exploration particularly under the influence of application of amendments at varying hydrological regimes and residence time. In this context, an incubation study was conducted to investigate the effect of application of three inorganic amendments (gypsum, rock phosphate and diammonium phosphate) on Pb fractions at two soil moisture regimes (flooding regime and 75% field capacity) and two incubation times (after 2 and 30 days) successively in non-saline/sodic and saline–sodic Pb-polluted paddy soils. After applied treatments, the concentration of Pb in five, i.e., exchangeable (F1), carbonate (F2), Fe–Mn oxide (F3), organic matter and sulfide bound (F4) and residual (F5) fractions, was assessed by sequential extraction. The results showed that the Pb spiked in the soils was significantly (P?≤?0.05) transformed from easily extractable (exchangeable and carbonate) fractions into less labile (Fe–Mn oxide, OM–S bound and residual) fractions. Among tested amendments, gypsum performed better in reducing the lability of Pb followed by DAP.  相似文献   
35.
The present study analyzes the prawn marketing chain before and after the implementation of a Danish-funded project (GNAEP) in three coastal districts of greater Noakhali, southeast region of Bangladesh. The results reveal that, before GNAEP, there was a longer prawn marketing chain with a number of intermediaries who used to share a considerable amount of market margin. However, after implementation of GNAEP, the prawn marketing chain has become shorter with a significant reduction of intermediaries which facilitates direct selling of prawns to processing plants through local Community Based Organizations (CBOs). The present prawn marketing system in the regions is in favor of prawn farmers. Farmers have greater advantages because 1) CBOs provide reasonable market price and actual weight, 2) CBOs can bargain with processing plants as the former are aware of the latest international market prices through Marketing Information System 3) number of intermediaries is lowered and 4) transport and preservation costs are reduced. The displaced intermediaries, some of whom are powerful persons in the society, have again started to influence the prawn market in different ways. This fact has opened up another discussion on how the power structure is shifting in this region and how they are affecting prawn marketing.  相似文献   
36.
The objective of this experiment was to evaluate the effect of foliar fertilization of some micronutrients [i.e., manganese (Mn) and boron (B)] on reproductive yield and fatty acid concentrations of a standard sunflower hybrid (‘NuSun 636') irrigated with different concentrations of saline water made by dissolving sea salt. Reproductive yield showed a significant decrease with the increase in salt in the rooting medium. However, foliar sprays of boric acid (H3BO3) and manganese chloride (MnCl2) showed a significant increase in seed number, seed weight, and oil content of seeds in the nonsaline control, which persisted even under saline water irrigation. An increase under the MnCl2 spray was more than with H3BO3 irrespective of non saline or saline water irrigation. Increasing levels of salinity appeared to be responsible for a decrease in oleic monounsaturated fatty acid concentration and an increase in the linoleic polyunsaturated, palmitic and stearic saturated fatty acid content whereas no significant change was found in linolenic polyunsaturated fatty acid content. Foliar applications of H3BO3 and MnCl2 brought some beneficial alteration in fatty acid concentrations of sunflower. Foliar application of H3BO3 caused a significant increase in palmitic and stearic saturated fatty acids and linoleic polyunsaturated fatty acids in control as well as under saline conditions. Oleic monounsaturated fatty acid concentration showed a decline under H3BO3 treatment irrespective to nonsaline or saline conditions. Foliar applications of MnCl2 increased the concentration of palmitic saturated fatty acid and oleic monounsaturated fatty acid irrespective to the plant growth under non saline or saline conditions. While stearic saturated fatty acid, linoleic and linolenic polyunsaturated fatty acid decreased with the application of manganese as compared to the non sprayed control.  相似文献   
37.
In the present investigation, different strains of Plant growth-promoting rhizobacteria (PGPR), namely Bacillus megaterium, Pseudomonas fluorescens and Bacillus subtilis were evaluated for their growth-promoting effects on wheat as well as on soil properties under field conditions at two different sites having sandy loam and silt loam type of soils. PGPR strains were evaluated either singly or in consortia. Amongst all the treatments, wheat inoculated with consortia was found most effective as it increased grain yield up to 53% over control in silt loam soil, whereas, corresponding effects in sandy loam soil were less pronounced as an increase of 31% was observed in corresponding treatments, respectively. Enhanced effects on soil properties were also more intense in silt loam as there was an increase of 205% organic matter as against sandy loam soil where this value was 110%.  相似文献   
38.
Variation in bread wheat including pre and post green revolutions varieties of Pakistan along with landraces was investigated for high molecular weight Glutenin subunits (HMW Gs) encoded at three genes (Glu-A1, Glu-B1, Glu-D1) with SDS-PAGE. The germplasm was diverse and unique on the basis of HMW Gs compositions and out of 14 alleles detected at all the Glu-1 loci, three belonged to Glu-A1, nine to Glu-B1 and two to Glu-D1 locus. High variation was observed in the landraces and higher gene diversity was observed between the populations as compared to the gene diversity within populations, whereas a reverse pattern of gene diversity was observed when populations were pooled across the region (higher within the regions than between the regions). A lack of relationship between the HMW Gs diversity and the altitude of collection site was observed. A data base has been generated in this study which could be expanded/exploited for cultivar development or management of gene bank.  相似文献   
39.
Species diversity and ethno-medicinal usage of 39 species of invasive plants were explored in and around two protected areas, Khadimnagar National Park (KNP) and Rema-Kalenga Wildlife Sanctu- ary (RKWS), of northeastern Bangladesh,. Status of invasive plants were investigated in 60 sample plots with 5 different habitat types, including forest, roadside, homestead, fallow land and others (ponds, canals, water logged areas, agricultural land, etc.). Data about the usage of invasive plants in traditional health care were collected through interviewing 110 households. Among the five habitat types, fallow land (28 species) pos- sessed the highest number of species, followed by roadside (25 species), forest (23 species), homestead (22 species) and others (13 species). Based on the survey, invasive plants of study areas were also categorized into five degrees of invasiveness e.g., naturalized, introduced, possibly invasive, moderately invasive and highly invasive. Additionally, there is the linear trend between degrees of invasiveness and use percentage of invasive plants. Total 39 species of invasive plants belonging to 29 fami- lies were recorded, which are generally used to treat 37 diseases, ranging from simple headache to highly complicated eye and heart diseases. The majority of the species used by the local inhabitants were herbs (16 spe- cies), followed by some shrubs (11 species), climbers (5 species), trees (5 species) and grasses (2 species). The use percentage of aboveground plant parts were higher (70.58%) than that of underground plant parts (16.18%).  相似文献   
40.
Stocking of all‐male fingerling produced by direct administration of male hormone 17‐α‐methyltestosterone is the most preferred method for present‐day aquaculture of the Nile tilapia Oreochromis niloticus. However, due to the growing concern of negative impact of steroid hormone in food fish, production of ‘genetically male’ tilapia, which depends on the concrete and thorough understanding of sex determination, has long been a scientific curiosity. The objective of the present study was to identify reliable sex‐linked markers and to evaluate the applicability of those markers in terms of monosex production approach. ‘XY’ neofemales were produced by using synthetic oestrogen and identified through selective breeding and progeny testing. Three females with progeny not deviating from 3:1 sex ratio (male:female) were designated as ‘XY’ neofemales and were used subsequently to produce putative YY progeny. Among the fifteen microsatellite markers tested, marker ARO172 was most informative in differentiating male and female genotypes. Twenty‐seven F2 fish from three families were identified as putative YY males based on marker genotyping, and four of them were crossed to produce F3 to validate marker association by progeny testing. The YY males produced 86%–100% male progeny indicating ARO172 a unique sex‐linked marker applicable in marker‐assisted selection.  相似文献   
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