Effect of sublethal concentrations of mercury on the composition of liver,muscles and ovary of Notopterus notopterus

The present investigation was undertaken to evaluate the effect of sublethal concentrations (0.088 and 0.044 mg 1^?1, i.e., 1/5th and 1/10th fraction of 96 h LC₅₀) of mercuric chloride on Ca, inorganic phosphate, water content, ash, glycogen, Fe, total protein, lipid contents and vitamin A, C, D, and E of liver, muscles and ovary of the freshwater fish Notopterus notopterus exposed for 30 days. The results obtained indicate that Ca, inorganic phosphate, water, ash, glycogen, Fe, total protein contents and vitamin D decreased significantly or insignificantly in these tissues of the Hg exposed fishes. However, lipid content increased in liver and muscles, but decreased in the ovaries. Vitamin A and D increased in the liver but decreased in the muscles and ovaries. Moreover, vitamin E increased in all the tissues of the fish exposed to 0.088 mg 1^?1 and decreased in the fish exposed to 0.044 mg 1^?1 of Hg concentrations.     

Vegetative Growth and Foliage Nutrient Content of Super Chief Apple under Different Irrigation and Fertigation Schedules in NW Himalayan Region

ABSTRACT

In the scheduling of nutrient supply programs, analysis of plant nutrient status has been found to be useful to prevent the deficiency or toxic effects of nutrients in any horticultural crop. So the present study was framed to assess the foliage nutrient content and vegetative growth under different irrigation and fertigation combination modules. Recently apple (Malus ×domestica) orchards in the state Himachal Pradesh of India have converted from the traditional royal delicious orchard at 6 × 6 m spacing with rainfed/basin irrigation to early spur varieties on dwarfing rootstock with drip irrigation, both with or without fertigation. An experimental field trial was started at the end of 2018 in a ‘Super Chief’/MM106 orchard at an experimental farm of the department of Soil Science & Water Management, Dr. YS Parmar University of Horticulture and Forestry, Nauni, Solan (HP). A factorial experiment with 16 treatment combinations of 4 irrigation levels viz. I_{1 –} drip irrigation at 100% ETc, I_{2 –} drip irrigation at 80% ETc, I_{3 –} drip irrigation at 60% ETc, I_{4 –} conventional irrigation, and four fertigation levels viz. F_{0 –} No fertilizer application (absolute control), F_{1 –} 100% of AD (NPK), F_{2 –} 75% of AD (NPK) and F₃ – 50% of AD (NPK) were replicated thrice with 3 plants in each replication. Vegetative growth parameters and leaf nutrient contents were affected by both fertilization and water rate. Irrigation and nutrient levels and their interactions exhibited significant effect on leaf N (3.10%), P (0.28%), K (1.77%), and S (0.44%) contents. Significantly maximum contents were observed in the irrigation level I₁ (DI at 100% ETc). Among fertigation level, F₁ [100% AD (NPK)] recorded highest contents of leaf N (3.17%), P (0.29%), K (1.80%), S (0.46%). Interaction I₁F₁ registered maximum leaf N (3.36%), P (0.36%), K (1.92%) and S (0.63%).

With an increase in the water volume and an increasing dose of NPK, vegetative growth parameters, i.e., tree height, plant spread, tree volume, trunk girth, and annual extension growth were noted to increase proportionately. Treatment DI at 100% ETc (I₁), increased the tree height by 9.41, plant spread (EW by 32.0, NS by 16.3), tree volume by 61.36, trunk girth by 8.05, and annual extension growth by 14.22% over conventional irrigation (I₄). Drip fertigated trees with F₁ [100% AD (NPK)] reported the highest growth parameters. The results of two years apple trial suggested a positive effect of fertigation on enhanced effectiveness of fertilization and improved foliage nutrient content and vegetative growth.     

Characterization of the interspecific cross Cicer anetinum L. ×C. judaicum (Boiss)

An interspecific cross involving Cicer anetinum L. and C. judaicum (Boiss) No. 182 was established. The F₁ could be distinguished from the parents by its prostrate growth habit at the seedling stage and through isozyme patterns for peroxidases and esterases. The inheritance of PRX-3 was found to be relatively simple and behaved as a monomer. Meiotic studies indicated the occurrence of six bivalents and four uni-valents in about 6% of F₁ PMC's at metaphase I, but normal 8–8 chromosomal distribution in anaphase I, indicating near complete homology. The F₁ hybrid was characterized for three morphological and six agronomical characters. A large F₂ was studied for secondary branches per plant, 100-seed weight (g), pods per plant, and grain yield per plant (g). Distributions of F₂ for pod number and grain yield displayed high C.V. and were highly skewed in a positive direction. F₂ recombinants were isolated with a very large number of secondary branches and a high pod number and yield. Such wide variability is not normally encountered in intevarietal crosses.     

Identification and characterization of quantitative trait loci related to lodging resistance and associated traits in bread wheat

Lodging is a major constraint to increasing yield in many crops, but is of particular importance in the small‐grained cereals. This study investigated the genetic control of lodging and component traits in wheat through the detection of underlying quantitative trait loci (QTL), The analysis was based on the identification of genomic regions which affect various traits related to lodging resistance in a population of 96‐doubled haploid lines of the cross ‘Milan’בCatbird’, mapped using 126‐microsatellite markers. Although major genes related to plant height (Rht genes) were responsible for increasing lodging resistance in this cross, several other traits independent of plant height were shown to be important such as fool and shoot traits, and various components of plant yield. Yield components such as grain number and weight were shown to be an indicator of plant susceptibility to lodging. QTL for lodging and associated traits were found on chromosomes IB, ID. 2B. 2D. 4B, 4D. 6D and 7D. QTL for yield and associated traits were identified on chromosomes IB, ID. 2A. 2B. 2D. 4D and 6A,     

Effect of probiotic on reproductive performance in female livebearing ornamental fish

A probiotic bacterial strain, Bacillus subtilis, isolated from the intestine of Cirrhinus mrigala (Hamilton), was incorporated in fish feed at four different concentrations (5 × 10⁸ cells g⁻², 5 × 10⁷ cells g⁻², 5 × 10⁶cells g⁻¹ and 5 × 10⁵ cells g⁻¹) and fed to four species of livebearing ornamental fish, Poecilia reticulata (Peters), Poecilia sphenops (Valenciennes), Xiphophorus helleri (Heckel) and Xiphophorus maculatus (Gunther) for one year duration to observe the effect of dietary probiotic supplementation on their reproductive performance. Sixty virgin females of each species were stocked separately in circular FRP tanks (350 L) and fed diets with varying levels of probiotic cells and control feed. Broodstock performance was evaluated based on gonadosomatic index (GSI), fecundity and fry production of female broodstock. The results showed that supplementation of feed with probiotics increased significantly (P<0.05) the GSI, fecundity and fry production of spawning females and length and weight of fry in all the four species of fish. The number of dead and deformed fry were also significantly lower (P<0.05) in fish fed with the probiotic feeds. The use of higher concentration of the probiont in diet did not always lead to significantly improved reproductive performance of the spawners. Collectively, this study showed that female livebearers benefit from inclusion of probiotics in diet during their reproductive stages.     

Recent advances in carp seed production and milt cryopreservation

The fish-seed production industry in India has recorded remarkable growth over the last three decades. The hypophysation technique was successfully introduced into India in 1957 and steady progress towards the refinement of the technique has been registered, which has revolutionized carp seed production in the Indian subcontinent. Advancement of carp maturity through brood stock management and multiple breeding has enabled spawn production well ahead of the monsoon and even beyond, ensuring seed availability throughout the year. The quality of seed is an important consideration for commercial aquaculturists. So, partial stock replenishment in carp hatcheries is practised to overcome the problem of inbreeding, which otherwise leads to poor growth of carps. Similarly, gametes of improved stock are cryopreserved and utilized for quality seed production as well as upgrading the brood stock of carps. The gamete cryopreservation protocol for carps is the focus of this review. An attempt has also been made to incorporate information on carp brood stock management, inducing agents, and seed production, including hatchery management.     

Effect of methyl parathion and chlorpyrifos on certain biomarkers in various tissues of guppy fish, Poecilia reticulata

Tests of acute toxicity were performed on the most common species of aquarium fish, Poecilia reticulata. Guppies (P. reticulata) were exposed to progressive concentrations of methyl parathion (MP) and chlorpyrifos (CPF); a semi-static method according to guidelines of OECD was used. Tests of acute toxicity were conducted using 10 fish for each separate concentration and for the control group. The results were subjected to probit analysis to determine the 96 h LC₅₀ values. The 96 h LC₅₀ values of MP and CPF to P. reticulata were 8.48 ppm/L (5.98–10.89) and 0.176 ppm/L (0.313–0.224) respectively. In addition, behavioral changes at each concentration were observed for the individual fish. Fish were exposed for 96 h to different sublethal concentrations of MP and CPF (¼ LC₅₀, 1/8 LC₅₀ and 1/10 LC₅₀) and their oxidative stress-induction potential was estimated in brain, liver and gills of fish. MDA content is induced in all tissues but maximum rise was observed in gills (161% and 153% for MP and CPF respectively). With regard to antioxidant defense system (ADS), GSH level decreased in the brain, liver and gills of tissues of MP treated fishes (22%, 6% and 13% respectively) and showed increase in brain and gills CPF treated (23% and 21% respectively). CAT, GST, GR and SOD levels fluctuated in all treatment groups relative to the control. Brain AChE showed dose-dependent inhibition in fish exposed to the higher concentrations reached 45% and 66% for MP and CPF respectively. Collective findings demonstrated that pesticide exposure of fish induced an increase in MDA and fluctuated ADS along with inhibited AChE. These findings may be used as valuable biomarkers for evaluation of water pollution.     

Forage production and nitrogen nutrition in three grasses under coconut tree shades in the humid-tropics

Reduction in forage production (FP) under trees in the humid tropics is well known, but information on how different levels of nitrogen (N) fertilizer influence FP under trees is meager. The present study reports effects of four N fertilizer levels (0, 60, 80 and 120 kg ha⁻¹ N) on net soil N mineralization rate (NMR) and soil moisture (SM), FP, shoot biomass/root biomass ratio (SB/RB), N concentration in SB, N uptake and nitrogen use efficiency (NUE) of three grasses [guinea (Panicum maximum Jacq.), para (Brachiaria mutica (Forssk) Stapf) and hybrid-napier (Pennisetum purpureum Schumach.)] under three canopy positions [under canopy (UC, representing high shade), between canopy (BC, representing low shade) and open] of coconut trees (Cocos nucifera L.) in a coconut based silvopastoral system in the humid tropical climate of South Andaman Island of India. The study was performed for two annual cycles (2005–2006 and 2006–2007). The hypotheses tested were: (1) FP would decline under tree shades, both in N fertilized as well as no N fertilized conditions, when SM was not growth limiting in the open. However, amount of decline in the FP would depend on grass species and intensity of shades i.e., higher was the shade greater would be the decline; (2) N fertilizer would increase FP under tree shades, but the increase depended on grass species, intensity of shades and amount of N applied. Amount of N applied, however, would not annul the shades effects when SM was not growth limiting in the open. The study revealed that the tree reduced light 59% under UC and 32% under BC positions, but the N fertilizer levels increased NMR by 11–51% under UC and 3–44% under BC positions compared to the open. SM did not differ across the canopy positions. Under all situations, FP of all grasses declined under UC (47–78%) and BC (18–32%) positions compared to the open; the decline was greater in Hybrid-napier than Guinea and Para grasses. Forage production of all grasses increased with N fertilizer increments under all canopy positions reaching 32 t ha⁻¹ dry matters for hybrid-napier at 120 kg ha⁻¹ N in the open. Both guinea and para grasses outyielded hybrid-napier grass under UC but not under BC or in the open. N concentration in the forage (SB) also increased as N fertilizer level increased. These observations support our hypotheses and suggest that forage production under coconut palms can be increased by the application of N fertilizer with both guinea and para grasses being more productive than hybrid-napier grass under the high shade. Where light conditions are better, hybrid-napier would produce more forage than the other species.     

Salt Tolerance of Some Oats (Avena sativa L.) Varieties at Germination and Seedling Stage

Soil salinity is the serious problem of the arid and semi-arid tracts of the world. It causes great losses to agriculture by lowering the yields of various crops. However, such soil may be utilized either after reclaimation or by growing tolerant plant species. The degree of salt tolerance varies not only with plant species but the different varieties of the same species show variation in salt tolerance. Germination and seedling stages have a bearing on plant development at later stages of growth and ultimately crop yield. Therefore, in the present investigation, twelve varieties of oats viz., Colabagh, Kent, JHO-801, JHO-802, JHO-810, JHO-815, JHO-816, S-3021, S-2688, Chauripatti, UPO-201 and Sierra were tested for their relative salt tolerance to increasing levels of salinity in those combination of salts which nearly exist in the natural salt affected soils. Seeds were sown in petri dishes and were exposed to five salinity (40, 80, 120, 160 and 200 me/L. of salts) levels. The germination percentage, root and shoot length and dry weight of the seedlings decreased with increase in salinity. In general, varieties JHO-815, JHO-802, JHO-816 and UPO-201 were found to be more tolerant at germination and seedling stages.     

Fuel and fodder from village woodlots: A Gujarat (India) experience

Having attained self-sufficiency in food production, India is now concentrating in using wastelands to increase its production of other products of agroforestry namely, fodder, fuel and small timber for the poorer section of society. Many agroforestry practices are being tried towards the attainment of this goal. In one such attempt, a 4 ha plantation was established in 1974 on Community grazing land in the village of Dhanori in Gujarat as a part of the State Village Forests Scheme. Casuarina equisetifolia was planted beca se it suited the site and because the villagers wished it. Grasses grew up naturally as a result of the enclosure. The trees were felled in 1983–4 and the distribution of benefits determined by the village panchayat. The internal Rate of Return was 35%. Villagers benefited from grasses, fuelwood and small timber for house construction and repair and from the employment generated. The success of the project led the village to organize itself into a Tree Grower's Society and undertake further planting in 1985–6. The demonstrated efficiency of the woodlot let to 200 ha of other plantations being established in the area. the poor benefited considerably from the project but if they had a greater say in the deliberations of the panchayat, the benefits could have been even greater. this agroforestry system has the potential of increasing the production of grasses, fuelwood, small timber and fruits (food) from wastelands.