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951.
A 12‐week growth trial was conducted to assess an improved soybean meal (ISBM) in the diet of Pacific white shrimp (PWS). Four isonitrogenous and isolipidic experimental diets were formulated: the control diet (ISBM‐0) contained 30% fishmeal (FM) and three test diets (ISBM‐33, ISBM‐66 and ISBM‐100) were formulated by gradually replacing FM on an isonitrogenous basis. Groups of PWS (3.2 g mean initial weight) were fed their respective experimental diets three times per day. Production performance of PWS was unaffected by diet, except the final weight of shrimp‐fed ISBM‐66 diet was significantly lower than those fed ISBM‐0. Whole‐body moisture was significantly higher and protein was significantly lower in PWS‐fed ISBM‐100 versus shrimp‐fed ISBM‐0. PWS‐fed ISBM‐66 had significantly higher oleic acid than shrimp‐fed ISBM‐0 and linolenic acid versus shrimp‐fed ISBM‐0 and ISBM‐100. The lowest linoleic acid and n‐6 polyunsaturated fatty acids levels were found in shrimp‐fed ISBM‐100. Based on second‐degree polynomial regression analysis of final weight and weight gain, the estimated optimum levels of ISBM to replace FM in PWS diets are 89.13% and 95.56% respectively. Overall, results indicate alternative, sustainable, plant‐based protein sources such as ISBM may potentially replace FM in PWS diets.  相似文献   
952.

The use of organophosphate pesticides (OPs) in agricultural practices in India has gained popularity due to their broad spectrum, low cost and high potency. Monocrotophos (an OP) which is a systemic and contact broad-spectrum cholinesterase inhibitor is being widely used in India. However, its use entails the damage to other non-target organisms such as fish. In the present study, zebrafish (Danio rerio) were exposed to various doses of monocrotophos (0.125, 0.625 and 1.25 μL/L) and genotoxicity studies were carried out employing the comet assay and micronucleus test in the peripheral blood of these fish after 24, 48 and 72 h of exposure. Significant DNA damage in the form of % tail DNA and micronuclei was observed in all the treated fish compared to the control. Both % tail DNA and micronuclei frequency were found to increase significantly as the concentration increased. DNA damage was also observed at all the time intervals for all treatments except in the 0.125 μL/L-treated group. A positive correlation was also observed between the comet assay and micronucleus test. The study thus suggests the use of zebrafish as an experimental model to study the genotoxic effects of agricultural pesticides using the comet assay and micronucleus test.

  相似文献   
953.
Phosphorus (P) in soil exists both in organic and inorganic forms and their relative abundance could determine P supplying capacity of soil. Differential input of exogenous and plant-mediated phosphorus and carbon in soil under different land-uses could influence P availability and fertilizer P management. While the effect of land-use on soil organic carbon (SOC) is fairly well-documented, its effect on soil P fractions is relatively less known. We investigated the effect of different land-uses including rice–wheat, maize–wheat, cotton–wheat cropping systems and poplar-based agroforestry systems on soil P fractions and organic carbon accrual in soils. Total P concentration was the highest under agroforestry (569 mg P kg?1) and the lowest under maize–wheat (449 mg P kg?1) cropping systems. On the contrary, soils under rice–wheat had significantly higher available P concentration than the agroforestry systems, probably because of higher fertilizer P application in rice–wheat and prevailing wetland conditions during rice growth. In soils under sole cropping systems viz. rice–wheat, maize–wheat and cotton–wheat, inorganic P was the dominant fraction and accounted for 92.2–94.6% of total P. However, the soils under agroforestry had smaller proportion (73%) of total P existing as inorganic P. Among soil P fractions, water soluble inorganic P (0.13–0.26%) represented the smallest proportion inorganic P in soils under different land-uses. Agroforestry showed significantly (p < 0.05) higher concentrations of SOC than the other land-uses. Soil organic C was significantly correlated with soil P fractions. It was concluded that poplar-based agroforestry systems besides leading to C accrual in soil result in build-up of organic P and the P supplying capacity of soil.  相似文献   
954.
The natural upper boundary of a forest (forest line) in mountain environments is an indicator of climate conditions. An increase in global average temperatures has resulted in an upward advance of the forest line. This advance may result in fragmentation of the alpine ecosystem and a loss of biodiversity. Therefore, it is important to identify potential areas where current forests can advance under scenarios of future climate change. I used expert knowledge and cartographic modeling to create a hybrid cartographic model considering five topographic variables to predict areas where forest line can expand in the future. The prediction accuracy of the model is around 82%. The model is able to predict areas above the current forest line that are suitable or unsuitable for future forest advance. Further inclusion of high-resolution satellite imagery and digital elevation models, as well as field-based information into the model can help to improve the model accuracy.  相似文献   
955.
Pigeonpea is an important food legume of the semi-arid tropics grown mainly under subsistence agriculture. As a first step to address the five decades-long yield stagnation, a proof-of-concept for a commercially viable CMS-based hybrid technology with high standard heterosis and fertility restoration has been demonstrated. Six generations of backcrossing and selection for male sterility, and agronomic superiority using a Cajanus cajanifolius- (A4 cytoplasm) based CMS donor (ICPA 2039) and a medium-maturity group recurrent parent ICPL 20176 (ICPB 2043) which resulted in a stable male sterile line (ICPA 2043) with near-perfect male sterility and superior agronomic traits. Following backcrossing and selections, the A-line (ICPA 2043) appeared to be morphologically similar in terms of various qualitative and quantitative traits compared to the B-line (ICPB 2043). However, differences between ICPA 2043 and ICPB 2043 were observed for days to maturity, 100-seed weight, pods plant-1, and seed weight plant-1. These differences may not be genetic but physiological. The best heterotic restorer line selected in a cross (ICPH 2671) combination restored a mean of 96.49% male fertility in 36 environments (12 locations, 3 years). Present investigation did not reveal significant G×E interaction for fertility restoration, indicating the possibility of obtaining high and stable grain yields in the pigeonpea growing areas of South and Central India.  相似文献   
956.
Two fast-growing Indian species, Melia composita Benth. and Eucalyptus tereticornis Sm., which have different sets of physical properties, were dried together in a vacuum press dryer(VPD) under two drying conditions,i.e., above boiling point(ABP) and below boiling point(BBP). The ABP and BBP conditions were maintained by keeping the temperature constant at 75 ℃ and maintaining two pressure levels: 300 mm of Hg(ABP) and 450 mm of Hg(BBP). In order to understand pressure conditions at the core during vacuum drying, a cylindrical brass pipe was inserted in both wood cores and attached with pressure gauges placed outside of the VPD. The results indicate that the Melia wood core attained equilibrium pressure immediately with the pressure of VPD, while Eucalyptus attained it very slowly, reaching equilibrium at later stages of drying when cracks and checks advanced to the core.The drying rate was higher for Melia than Eucalyptus under both drying conditions. The drying rate of Melia(ABP) was higher than Melia(BBP), however, the drying rate for Eucalyptus(ABP) was not significantly different from the BBP drying rate.  相似文献   
957.
Plantation-grown progenies of Melia composita Willd.were studied for variability in several physical properties: density,radial and tangential shrinkage,longitudinal permeability of heartwood and sapwood.Furthermore,flat-sawn planks from each of the progeny were subjected to a quick-drying test for determination of kilndrying schedule.The mean density of the species was 0.39 g cm~(-3) and the wood may be categorized as light wood.Mean radial shrinkage(%) for the species was 2.8% with progeny-wise variation in radial shrinkage from 1.56 to 4.11%.Mean tangential shrinkage(%) for the species was 5.54% with progeny-wise variation in tangential shrinkage from 3.69 to 7.71%.The resultant tangentialradial shrinkage ratio was 1.98(less than two),which suggests that the wood is relatively stable with respect to drying behavior.Mean sapwood and heartwood longitudinal permeability of the species were 3.38 and 2.02 Darcy,respectively.Higher longitudinal permeability of sapwood and heartwood indicate better drying and preservative properties of the species.Terazawa quick-drying test method suggests that the species is less susceptible to drying defects.During the test,only moderate checks and cracks were observed.A tentative kiln-drying schedule was recommended based on these results.  相似文献   
958.
The present study was conducted to study the genetic architecture of grain micronutrients (Zn, Fe and β-carotene contents), grain protein content and four yield traits in a spring wheat reference set comprising 246 genotypes. Phenotypic data on these traits recorded at two locations and the genotyping data for 17,937 SNP markers (obtained through outsourcing) were used for genome wide association study, which gave following results after Bonferroni correction using four methods: (1) single locus single trait analysis gave 136 marker-trait associations; (2) multi-locus mixed model gave 587 MTAs; (3) multi-trait mixed model gave 28 MTAs and (4) matrix-variate linear mixed model gave 33 MTAs. As many as 73 epistatic interactions were also detected. Keeping all the results in mind, nine most important MTAs were selected for biofortification. These markers were associated with three traits (GPC, GFeC and GYPP). These MTAs can be used in wheat improvement programs either using marker-assisted recurrent selection or pseudo-backcrossing method.  相似文献   
959.
With the exception of Cajanus cajan (L.) Millspaugh (pigeonpea), the remaining species of genus Cajanus have not been domesticated. For millennia these taxa have persisted in natural habitats through self-sown seeds. These wild species are an asset for sustaining future pigeonpea breeding programmes since they contain certain traits (genes) that are necessary for encountering various breeding challenges related to crop improvement and adaptation. In this review we identify the key traits from wild Cajanus species, and discuss various physical and genetic constraints encountered in their utilization in introgression breeding. Some noteworthy achievements recorded from inter-specific breeding programmes in pigeonpea are also discussed. These include the development of (1) high protein (>?28%) genotypes (2) cytoplasmic nuclear male sterility systems (3) highly (>?95%) self-pollinating genotypes, and (4) resistance sources to sterility mosaic disease, nematodes, salinity, photo-insensitivity, pod borers, podfly, bruchids, and Phytophthora blight. To help pigeonpea breeders engaged in inter-specific breeding programmes, we suggest the division of the secondary gene pool germplasm into two sub-group/tiers on the basis of ease in hybridization.  相似文献   
960.
Adoption of pigeonpea hybrids in central and southern India is showing high impact with on‐farm yield advantages of >30%. The hybrid pigeonpea technology, the first in any legume crop, is based on a cytoplasmic‐nuclear male‐sterility (CMS) system. For a long‐term sustainability of hybrid programme, it is imperative that both nuclear diversity and cytoplasmic diversity are maintained among hybrid parents. In this context, a continuous search for new CMS‐inducing cytoplasms is necessary. This paper reports detection of maternal inheritance of male sterility in the progeny derived from a natural hybrid between a wild relative [Cajanus lineatus (W. & A.) Maesen comb. nov.] of pigeonpea and an unknown pigeonpea [Cajanus cajan (L.) Millsp.] genotype. In the present study, the male sterility was maintained up to BC7F1 generation by an advanced breeding pigeonpea line ICPL 99044. This male sterility inducing cytoplasm of C. lineatus was tagged as A6. In future, this CMS genetic stock can be used to develop a range of new pigeonpea hybrids with high yield and adaptation.  相似文献   
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