Effect of hot water extracts of brown seaweeds Sargassum spp. on growth and resistance to white spot syndrome virus in shrimp Penaeus monodon postlarvae

An experiment was conducted to evaluate the effect of a hot water extract of brown seaweeds Sargassum duplicatum and Sargassum wightii on the growth and white spot syndrome virus (WSSV) resistance in shrimp Penaeus monodon postlarvae (PL). Artemia nauplii (instar II) were enriched with both seaweed extracts at various concentrations (250, 500 and 750 mg L^?1) and fed to the respective P. monodon (PL15–35) group for 20 days. A control group was also maintained without seaweed extract supplementation. The weight gain of the experimental groups was significantly higher (0.274–0.323 g) than the control group (0.261 g). Similarly, the specific growth rate was also significantly higher (16.27–17.06%) in the experimental groups than in the control group (16.03%). After 20 days of the feeding experiment, the shrimp PL were challenged with WSSV for 21 days. During the challenge test, the control shrimp displayed 100% mortality within 8 days. In contrast, the mortality percentage of the highest concentration (750 mg L^?1) of seaweed extract enriched Artemia nauplii fed shrimp was 54–79%. Comparatively, low mortality was observed in S. wightii extract‐enriched Artemia nauplii fed shrimp. The polymerase chain reaction analysis indicated the concentration‐dependent infection of WSSV in P. monodon PL.     

Effects of stocking density and presence or absence of soil base on growth,weight variation,survival and body composition of pearlspot,Etroplus suratensis (Bloch) fingerlings

With the objective to develop an indoor tank seed rearing system for pearlspot (Etroplus suratensis), effects of three stocking densities in presence or absence of soil base were evaluated on growth, weight variation, survival and body composition in a 60‐day trial. The experiment had a 3 × 2 factorial design with three levels of stocking density (150, 300 and 450 fish m^?3) and two levels of soil base (with and without) in triplicates. Pearlspot fry (27.5 ± 0.5 mm/0.39 ± 0.02 g) were stocked in experimental tanks (Length×Breadth×Height: 0.65 × 0.50 × 0.48 m) and fed with a formulated diet containing 29.85% crude protein. Increasing the stocking density from 150 to 450 fish m^?3 significantly decreased the growth (average body weight and total length), daily weight gain, specific growth rate and survival (P < 0.001) and increased the feed conversion ratio (P < 0.01). Significantly lower growth and survival were observed in treatment having soil base compared with that of without soil base (P < 0.001). However, coefficients of variation at harvest weight and body composition of fingerlings were independent to stocking density and presence or absence of soil base (P > 0.05). A significant positive interaction effect of stocking density and presence or absence of soil base was observed on average body weight (P < 0.05) and survival (P < 0.001) of pearlspot fingerlings. This study suggests that stocking density of 150 fish m^?3 without soil base in tanks would be appropriate for raising pearlspot fingerlings in brackishwater indoor seed rearing system.     

Effect of stocking density on soil,water quality and nitrogen budget in Penaeus monodon (Fabricius, 1798) culture under zero water exchange system

Soil and water interactions and their influence on growth and production in different densities (SD8 & SD16) under zero water exchange were studied in two successive crops of Penaeus monodon in Tamil Nadu, India during 2007 and 2008. Scraping and tilling during pond preparation increased the mineralization rate than scraping only. During crop, there was no significant difference in soil organic carbon and total nitrogen between the SDs. However, as the crop progressed, organic carbon and total nitrogen content of the soil showed significant difference under both the SDs. Between the SDs, nitrate and phosphate content in water significantly differed, whereas the progress of the crop significantly increased both available and total nutrients. Mass balance of nitrogen indicated that applied feed contributed to 97.4–98.5% of input nitrogen, of which nitrogen in sediment accounted for 16.5–27.3%, nitrogen recovery in shrimp was 34.2–43.6% and the nitrogen lost through denitrification and volatilization varied from 4.7% to 34.7%. Zero water exchange system is highly efficient as nitrogen recovery is higher in shrimp and lower in discharge water. Lack of significant difference in metabolites between the SDs indicates the role of aeration and probiotics in sustaining SD16 cultures.     

CNS activity of Alstonia macrophylla leaf extracts: an ethnomedicine of Onge of Bay Islands

Methanol extract at 100-200 mg/kg p.o. and major nonpolar fraction B at 50 mg/kg of Alstonia macrophylla leaves caused a significant reduction in spontaneous activity, remarkable decrease in exploratory behavioural pattern, a reduction in muscle relaxant activity and also significantly potentiated phenobarbitone sodium-induced sleeping time. The phytochemical study of crude leaf extract revealed the presence of tannin, triterpenoid, flavonoid, sterol, alkaloid and reducing sugars. Further fractionation and purification of the n-butanol part of methanol extract yielded fraction A, fraction B and fraction C along with some minor fatty acids as the major compounds.     

Effect of macrophage secretory products on elaboration of virulence factors by planktonic and biofilm cells of Pseudomonas aeruginosa

Macrophages, which constitute the first line of defense, pour their secretions in the mileu following stimulation with pathogens. These secretory products, referred to as macrophage secretory products (MSPs), can influence ultimate outcome of an infection. In the present investigation, it was observed that different strains of Pseudomonas aeruginosa vary in their ability to stimulate macrophages leading to variability in generation of macrophage secretory products. Cytokine levels, reactive nitrogen intermediates and protein content of macrophage secretory products generated with biofilm cells of P. aeruginosa was found to be more as compared to their planktonic counterparts. The effect of macrophage secretory products produced in response to interaction of macrophages with P. aeruginosa on elaboration of virulence factors produced by planktonic and biofilm cell forms of this pathogen was assessed. Significant enhancement in growth and elaboration of all the virulence determinants by both the cell forms was observed when P. aeruginosa was grown in presence of supernatants with macrophage secretory products. Implications of these findings in relation to urinary tract infections induced by P. aeruginosa have been discussed.     

Fingerprinting in cucumber and melon (<Emphasis Type="Italic">Cucumis</Emphasis> spp.) Genotypes using morphological and ISSR markers

In the present investigation, 13 Cucumis genotypes from different geographical areas of India were screened for genetic diversity using 19 morphological traits and 15 ISSR primers. The analysis of morphological traits grouped the accessions into six clusters. Cluster V contained the maximum number of genotypes namely Kanivellari, Long Green, Andaman Local, Perundurai Local, and Sempatti Local. Clusters I and VI contained the minimum number of genotypes. Among all the characters, the highest mean value was observed in fruit length (23.38) and the lowest mean value was observed in stripes on the blossom end (1.31). The 15 ISSR primers generated 109 polymorphic alleles. The average number of ISSR alleles generated was 8.3 per primer and the level of polymorphism was 87.20%. The ISSR primer UBC 825 was highly informative with a PIC value of 0.8934. The 13 genotypes were grouped into six clusters based on ISSR markers. Cluster III contained the maximum number of genotypes, namely Kanivellari, Sankagiri Local, Perundurai Local, Long Melon, and Sempatti Local, while Clusters I, II, IV, and V (Karur Local, Andaman Local, Edapaddi Local, and N 78, respectively) contained the minimum number of genotypes. The ISSR profile generated genotypes specific allele namely, UBC 812_700bp and UBC 812_1000bp for Cluster VI which contained Cucumis genotypes collected from the northern part of India. Similarly, UBC 808 produced specific allele UBC 808_650bp formed in Cluster III which contained genotypes collected from Tamil Nadu and Kerala.     

Ecological stability of genetic diversity among landraces of little millet (<Emphasis Type="Italic">Panicum sumatrense</Emphasis>) in south India

Risk-prone agriculture by resource-poor tribal farmers in Kolli hills, south India is slowly giving way to commercial exploitation for paltry compensation thus eroding genetic diversity of millets. Cultivation and conservation of millets, particularly, little millet (Panicum sumatrense Roth ex Roem. et Schult.), called samai in the local language, Tamil are on the wane. Whether irregular and sparse cultivation of little millet by tribals has an impact on the current level of genetic divergence is also not clear. Therefore genetic divergence among 7 landraces and 1 check variety was evaluated based on morphometric traits at two sites over two seasons. The seven landraces formed six distinct groups with high inter-group distances. Days to maturity and flowering time contributed the most to genetic differentiation. Principal component analysis confirmed the results of divergence analysis. But a recent molecular analysis of diversity reported that the landraces were all genetically uniform and any observed diversity could be due environmental variation. An analysis of the contradictory results only emphasized the fact that lack of polymorphism need not imply lack of genetic divergence. The findings co evaluated with relevant published work highlight the value of morphometric analysis and reveal sustained genetic divergence in little millet.     

Atmospheric pressure ionization LC-MS-MS determination of urushiol congeners

This paper describes atmospheric pressure ionization (API) LC-MS-MS determination of urushiols, 3-n-alkenyl- and -alkyl-substituted catechols responsible for poison oak dermatitis. Urushiol was isolated from Western poison oak according to the method of Elsohly et al. (1) (J. Nat. Prod. 1982, 45, 532-538)-the purified preparation contained C(17)- and C(15)-substituted urushiols with zero, one, two, and three double bonds as determined from GC-MS analysis of trimethylsilyl derivatives. Urushiol mixtures were separated on a C(18) reversed phase HPLC column with a methanol-water gradient with urushiols eluting in 100% methanol. Atmospheric pressure chemical ionization (APCI) produced primarily [M - H](-) and MH(+) molecule ions. Electrospray ionization (ESI) yielded [M - H](-) and adduct ions including [M + Cl](-). Daughter ions of [M - H](-) included quinoid radical anions ([M - H - H(2)](-) and m/z 122(-)) and a benzofuran phenate (m/z 135(-)). A suite of hydrocarbon fragments were produced by collision-induced dissociation of MH(+) directly or via an intermediate [MH - H(2)O](+) daughter ion. Six urushiol congeners, one not previously reported in poison oak, were determined by negative ion API-LC-MS-MS with detection limits of approximately 8 pg/microL (ESI) and approximately 800 pg/microL (APCI). API-LC-MS-MS was used to determine urushiol in surface wipes, air samples, and plant materials.     

Effect of mixed-cropping and water-stress on macro-nutrients and biochemical constituents of rhizomatous medicinal plants in Central Himalaya, India

Plants in the alpine zone mainly depend on the reserved food materials stored in their rhizomes for the next growing season.We investigated the effect of mixed cropping(Phaseolus vulgaris L.var.Pinto) with four rhizomatous medicinal plants,i.e.,Angelica glauca,Arnebia benthamii,Rheum emodi and Pleurospermum angelicoides as well as three levels of water stress treatment under two conditions(shade net and open field) on macronutrients(NPK) and biochemicals(carbohydrates and protein).The experiment was conducted by completely randomized design(CDR).The data were analyzed with ANOVA as well as CDR.The experimental results show that in all the species shade conditions with sever water stress(SSWS) increased the level of macronutrients(NPK).However,(N) concentration was highest under shade with mixed cropping(SMIX).Under SMIX,carbohydrate content was highest than open field control conditions(CONT).This investigation results demonstrate that mixed cropping of medicinal plants with Phaseolus vulgaris could be a good livelihood option in the mountainous regions of Indian Central Himalaya.And the water-stress conditions along with mixed cropping could improve the biochemical constituents in the rhizome of these species.     

Antiviral Effect of Fucoidan Extracted from the Brown Seaweed,Sargassum wightii,on Shrimp Penaeus monodon Postlarvae against White Spot Syndrome Virus

This study was carried out to determine the effect of seaweed polysaccharide, fucoidan from brown seaweed, Sargassum wightii, on Penaeus monodon postlarvae (PL) against white spot syndrome virus (WSSV). The fucoidan was extracted from S. wightii, and the yield was observed as 2.832 ± 0.204%. Artemia franciscana nauplii were enriched with extracted fucoidan at four different concentrations (100, 200, 300, and 400 mg/L) and fed to shrimp P. monodon PL for 20 d. After feeding experiment, the P. monodon PL were challenged with WSSV, and the mortality percentage was recorded daily up to 21 d. During the challenge test, the control PL showed 100% cumulative mortality within 9 d, but the fucoidan‐enriched Artemia nauplii fed groups of PL exhibited 60–94% cumulative mortality within 21 d. The reduction in mortality percentage of experimental groups of PL over control PL was ranged between 33.71 and 61.65%. The polymerase chain reaction analysis confirmed the concentration‐dependent variation in WSSV infection.