Nano zinc vis‐à‐vis inorganic Zinc as feed additives: Effects on growth,activity of hepatic enzymes and non‐specific immunity in rohu,Labeo rohita (Hamilton) fingerlings

The effects of dietary administration of inorganic zinc (zinc sulphate, ZnSO₄) and nano zinc (zinc oxide nanoparticles, ZnO‐NP) were evaluated in rohu, Labeo rohita fingerlings. Fish were fed with a basal diet (Control) supplemented with ZnSO₄ (T1, T2 and T3) and ZnO‐NP (T4, T5 and T6) at 10, 20 and 30 mg/kg, respectively, for a duration of 45 days. The results revealed that fish fed diet containing 20 mg ZnO‐NP per kg (T5) had the highest weight gain and specific growth rate (SGR, % per day), which was significantly different (p < .05) from the other experimental diets. Significantly (p < .05), higher activities of the digestive and metabolic enzymes were recorded in the fish fed ZnO‐NP containing diets as compared to the diets containing inorganic Zn or control diet. The maximum serum glucose and protein levels were noted in fish reared on diet T5. Both SGOT and SGPT activities were significantly increased in fish fed Zn‐supplemented diets (T1 to T6), as compared to the control group. Similarly, innate immune parameters were improved with feeding Zn incorporated diets. The highest phagocytic (40.74 ± 0.65%) and respiratory burst (0.33 ± 0.001, OD 630nm) activities were recorded in the fish fed diet containing ZnO‐NPs at 20 mg/kg (T5). The maximum superoxide production and serum peroxidase activity were detected in the fish fed T5 and T6 diets. Overall, results indicated that short‐duration feeding (≤45 days) of dietary ZnO‐NP (20 mg/kg) improved growth, enzyme activity, serum biochemical parameters and immune function in rohu fingerlings.     

Fabrication and in-pond operation of a low-cost,semiautomated portable carp hatchery with a temperature-adjustability feature

The present study describes a simple, portable, and inexpensive in-pond hatchery model assembled from locally available materials for seed production of small and medium-sized carp at high efficiency. This light-weight hatchery requires minimal engineering skills for assembly and operation. Further, the hatchery water supply mechanism has built-in components to filter out sediments and zooplankton from the pond water besides maintaining the water temperature 5°C–7°C lower than the pond surface water by drawing water from a metalimnion layer without additional energy requirements. Spontaneous spawning, automatic transfer of eggs to the incubation tank, and 80% hatching rates at an egg-holding capacity of 2,000 eggs/L was recorded for Barbonymus gonionotus, Labeo bata, and Labeo rohita with minimal human intervention. The production capacity of 0.06 million fry per cycle and estimated benefit-cost ratio of 2.48 demonstrated the high efficiency and economic feasibility of this portable hatchery.     

Protective immune responses of recombinant VP2 subunit antigen of infectious bursal disease virus in chickens

Infectious bursal disease virus (IBDV) is the causative agent of Gumboro disease and poses a huge threat to poultry industry. The risks associated with conventional attenuated viral vaccines make it indispensable to probe into the development of novel and rationally designed subunit vaccines which are safer as well as effective. VP2 is the major host-protective antigen found in IBDV capsid. It encompasses different independent epitopes responsible for the induction of neutralizing antibody. Here, we report the efficacy of the immunodominant fragment of VP2 which induces both humoral and cellular immunity against infectious bursal disease. A 366bp fragment (52-417bp) of the VP2 gene from an IBDV field isolate was amplified and expressed in Escherichia coli as a 21kDa recombinant protein. The efficacy of rVP2(52-417) antigen was compared with two commercial IBDV whole virus vaccine strains. The rVP2(52-417) induced significantly high antibody titres in chicken compared to commercial vaccines and the anti-rVP2(52-417) sera showed reactivity with viral antigens from both commercial strains (P<0.0001) and field isolates. Also, the chicken splenocytes from rVP2(52-417) immunized group showed a significantly high proliferation (P<0.01) compared to other groups, which implies that the rVP2(52-417) fragment contains immunogenic epitopes capable of eliciting both B and T cell responses. Further, rVP2(52-417) conferred 100% protection against vIBDV challenge in the immunized chickens which was significantly higher (P<0.001) compared to 55-60% protection by commercial vaccine strains. Hence, the study confirms the efficacy of the immunodominant VP2 fragment that could be used as a potent vaccine against IBDV infection in chicken.     

Management strategies for sustainable yield of potato crop under high temperature

High temperature has a deleterious effect in productivity of cool season crops like potato. This study was conducted to assess the efficacy of soil management practices to high-temperature tolerance in potato. Two popularly grown potato cultivars of northeast India, Kufri megha and Rangpuria, were sown under optimal and high-temperature conditions with soil application of inorganic nutrients (N, P, K, Ca, Zn), organic amendment, i.e. farm yard manure (FYM), and straw mulch. This integrative soil management practice showed significant positive influence on membrane integrity, chlorophyll content, total soluble sugars and superoxide dismutase activity of potato plant. Higher tuber bulking rate and tuber yield in both optimal and high-temperature situation was recorded under these soil applications. Kufri megha performed better with the application of Ca and Zn along with straw mulch, while Ca with farm yard manure substantially improved restore yield in Rangpuria. Application of CaSO₄ and ZnSO₄ (20 and 60 kg ha^?1, respectively) with FYM and straw mulch (10 and 6 t ha^?1, respectively) can mitigate the high-temperature stress in potato grown in acidic soil (deficient of Ca and Zn) of northeast India.     

Genetic diversity of ash gourd [Benincasa hispida (Thunb.) Cogn.] inbred lines based on RAPD and ISSR markers and their hybrid performance

Ten inbred lines of ash gourd [Benincasa hispida (Thunb.) Cogn.] were crossed to produce 45 F₁ hybrids (without reciprocal) which were evaluated along with the parents for 20 growth- and yield-related traits, in a replicated field trial. High level of heterosis was observed among the hybrids for most of the traits examined, including yield. These inbred lines were analysed by using 42 RAPD primers those produced 282 DNA marker bands. A total of 130 RAPD markers were obtained with a mean of 3.1 per primer, which in combination discriminated all the inbreds from each other. Pair-wise genetic distance measurements ranged from 0.07 to 0.31, suggesting a wide genetic diversity for these inbreds. These inberds were also analysed with five ISSR primers of which four were informative. Twenty-six ISSR marker bands were generated of which 11 were polymorphic with an average of 2.80 per primers. The percentage of polymorphic bands produced were higher in ISSR markers (>80%) than generated through RAPD markers (46%). Although the results indicated significant positive correlations of genetic distance with hybrid performance and heterosis, the RAPD based genetic distance measures and use of limited ISSR markers in this present study could not effectively predict hybrid performance in this crop. The genetic variation among ash gourd inbred lines examined, herein, defined a marker array (combined ISSR and RAPD) for the development of a standard reference for further genetic analyses, and the selection of potential parents for predicting hybrid performance and heterosis.     

Toxicity ameliorative effect of vitamin E against super-paramagnetic iron oxide nanoparticles on haemato-immunological responses,antioxidant capacity,oxidative stress,and metabolic enzymes activity during exposure and recovery in Labeo rohita fingerlings

Aquaculture International - The present study assessed the toxic effect of super-paramagnetic iron oxide nanoparticles (SPIONs) on haemato-immunological responses, antioxidant capacity, oxidative...     

Indole acetic acid and ACC deaminase-producing <Emphasis Type="BoldItalic">Rhizobium leguminosarum</Emphasis> bv. <Emphasis Type="BoldItalic">trifolii</Emphasis> SN10 promote rice growth,and in the process undergo colonization and chemotaxis

This study focuses on the chemotaxis, colonization and rice growth promoting ability of indole acetic acid (IAA) and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase-producing rhizobacteria Rhizobium leguminosarum bv. trifolii SN10, previously isolated from root nodules of Trifolium alexandrium L. We show here that R. leguminosarum bv. trifolii SN10 promote the growth of four different rice varieties grown in India in terms of biomass, root branching and N content. In addition, using scanning electron microscopy and viable cell counts, we provide evidence that the bacteria successfully colonize the root surface of the rice variety which showed maximum growth promotion upon inoculation. Not only this, R. leguminosarum bv. trifolii SN10 exhibit a strong chemotaxis response towards the rice seed and root exudates despite the presence of a bacteriostatic phenolic compound, 7-hydroxycoumarin (umbelliferone). Further, R. leguminosarum bv. trifolii SN10 secretion of phytohormones such as IAA and ACC deaminase suggest the potential of the plant growth promoting rhizobacteria to be used as biofertilizer to enhance rice crop production in the subcontinent.     

Molecular diversity and phenetic relationship of Momordica spp. of Indian occurrence

Twenty-one RAPD and twelve ISSR primers were used for assessment of genetic diversity and establishing phenetic relationships among 35 genotypes of six currently cultivated Indian Momordica species and five genotypes of two Luffa species. A total of 436 RAPD and 230 ISSR scorable fragments were produced of which 99.8% fragments showed polymorphism among the species and varieties of Momordica and Luffa. The level of polymorphism detected by the 33 random primers was higher among the species (99.8%) of Momordica than that estimated among the varieties (61.3%). The varieties belonging to dioecious Momordica species (75.6%) showed a higher level of polymorphism as compared to monoecious species (50.3%). A significant level (68.6%) of polymorphism however was detected by the two marker types among the Indian varieties of monoecious M. charantia species. A wider range of molecular diversity (16–95%) detected by both RAPD and ISSR markers reflected presence of high level of genetic variation among the species and Indian varieties of Momordica and Luffa. The level of inter-specific diversity was maximum (90%) between annual monoecious M. charantia and perennial dioecious M. cochinchinensis whereas the extent of intra-specific diversity was highest particularly in dioecious species (51%) as compared to monoecious species like M. charantia (38%). Wider divergence of the taxon of controversial identity, M. cymbalaria from the other Indian cultivated Momordica species and their evolutionary closeness with Luffa species was evident. The clustering pattern obtained among the 40 genotypes belonging to different Momordica and Luffa species corresponded well with their morphological, cytological and taxonomic classification, which was further supported by high boot-strap values and PCA analysis. Species and genotype-specific fragments detected by the random markers would be useful in introgression breeding for genetic improvement of Momordica cultivated in India. A smaller set of 28 informative random markers screened in this study could precisely differentiate the Momordica genotypes from each other and thus would be of use in many marker-based genotyping applications in Momordica.     

Evaluation and impact assessment of culture‐based fisheries to enhance fish yield in small reservoirs in Odisha State,India

The present study investigates the success of stocking fingerlings of Indian major carps ‐Gibelion catla (Hamilton), Labeo rohita Hamilton and Cirrhinus mrigala Hamilton – to enhance fish yield in 58 small reservoirs in Odisha State, India. Fish stocking and yield data were collected from State Fisheries Department, Odisha. The relationships between area, stocking density and fish yield of different size groups of reservoirs were assessed using the Pearson correlation coefficient (r). Fish yield increased significantly (p < 0.05, t‐test) from 204 kg/ha/year in 2012–13 to 323 kg/ha/year in 2013–14 due to adoption of CBF. The corresponding per capita fish production increased from 398 kg fisher^?1 year^?1 to 702 kg fisher^?1 year^?1 benefitting more than 8,000 fisher households. Reservoirs in the size group 100–500 ha showed the highest response of fish yield with respect to stocking of fingerlings. The size of fingerlings at stocking and area of the reservoir had greater impact on enhancing fish yield. Stocking had a profound positive impact on fish yield. This study forms a baseline evaluation of the impact of stocking on small tropical reservoirs in India. It also recommends management measures and discusses issues, and the way forward for sustainable fisheries enhancement in small tropical reservoirs in eastern India.