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101.
The first enzyme of the basidiomycete Piptoporus soloniensis, a peptidase (PsoP1), was characterized after isolation from submerged cultures, purification by fractional precipitation, and preparative native-polyarylamide gel electrophoresis (PAGE). The native molecular mass of PsoP1 was 38 kDa with an isoelectric point of 3.9. Similar to chymosin from milk calves, PsoP1 showed a maximum milk-clotting activity (MCA) at 35-40 °C and was most stable at pH 6 and below 40 °C. The complete inhibition by pepstatin A identified this enzyme as an aspartic peptidase. Electrospray ionization-tandem MS showed an amino acid partial sequence that was more homologous to mammalian milk clotting peptidases than to the chymosin substitute from a fungal species, such as the Zygomycete Mucor miehei. According to sodium dodecyl sulfate-PAGE patterns, the peptidase cleaved κ-casein in a way similar to chymosin and hydrolyzed β-casein slowly, as it would be expected from an efficient chymosin substitute.  相似文献   
102.
Tropical Animal Health and Production - It is known that using antibiotics by way of growth promoters has harmful side effects on both animals and consumer health due to cross-resistance among...  相似文献   
103.
Effects of NaCl, KC1, and CaCl2 alone, and in combinations of NaCl/KCl and NaCl/CaCl2 on growth and ion uptake by ‘Kallar'grass in soil and in solution cultures were studied. In soil up to 150 mM NaCl and KCl had little effect on growth but CaCl2 depressed growth strongly. Dry weights in 150 mM NaCl/KCl decreased but remained little affected in NaCl/CaCl2. Plant response to Na+ was little affected by Ca++ or K+ and no interactions between Na+ and Ca++ or Na+ and K+ were observed. Plant tissue exhibited a strong selectivity for K+ over Na+ Concentrations of Na and Cl in the tops exceeded those in the roots. Leaf transections are presented providing some information on the tissue anatomy.  相似文献   
104.
Abstract

Groups of “Kallar”; grass plants were subjected to various treatments of 100 mM NaCl simultaneously labelled with 22Na+ and 36Cl?. On the basis of the specific activity, the distribution of Na and Cl? in the tissue was followed during and after treatment, i.e. after transfer of some groups to an identical but inactive solution. Sequential collections of leaf washes showed that both Na and Cl? were extruded at a somewhat constant rate. Leaf sheaths accumulated more Na+ and Cl? than the leaf blades and the amounts of Na+ and Cl? in the leaf sheaths as a percentage of their total plant content (i.e. 28% and 31%) approximated the amounts of Na and Cl? extruded by the leaves (i.e. 23%). Moreover, almost equivalent amounts of Na+ (21%) and Cl? (29%) were removed by root efflux which continued even several days after transfer of the plants to the inactive, saline solution. Part of the Na+ and Cl? was retranslocated from the tops to the roots and was attributed to phloem export.

Tolerance of Kallar grass to NaCl was thus related to preventing the tissue from accumulating high concentration by extrusion of both Na+ and Cl? by the leaves and their efflux by the roots in addition to an equivalent retention in the leaf sheaths.  相似文献   
105.
Three‐week‐old nodulated faba bean plants were subjected to two levels of water stress (0.5 and 0.25 field capacity; soil water content of 20 and 10%) for five weeks. Half of the stressed plants was treated with potassium chloride (KC1) at 10 (K1) and 150 mg (K2)/kg soil at the beginning of water deficit. Nodulation was examined and some nodule activities were assayed. Nodulation, nitrogenase activity, total nitrogen (N), and dry matter yield were significantly decreased by increasing stress but were significantly higher with the two levels of potassium (K) supply. Leghaemoglobin and protein contents of cytosol as well as nodule protease and invertase were severely depressed by drought stress. Soluble carbohydrate contents of nodules, however, was significantly increased. Protein and leghaemoglobin contents and enzyme activities were greater with K fertilization but less soluble carbohydrate was accumulated. The results indicate that K supply, particularly at the 150 mg/kg soil level, increased faba bean resistance to water stress.  相似文献   
106.

Two field trials were conducted in 2018 and 2019 to develop practical and economically efficient weed control programs in corn. The experiment included six treatments (cowpea, rice straw, sorghum extract, hoeing, foramsulfuron herbicide and weedy check). The treatments were arranged in randomized complete block design with four replicates. Findings showed that reduction in total weed number was evident with application of hoeing, cowpea and rice straw in 2018 and 2019 seasons, in addition to foramsulfuron herbicide and sorghum extract in 2019. Cowpea, hoeing, foramsulfuron herbicide and rice straw recorded higher reduction in dry biomass of grassy weeds in both seasons. Reductions in N, P and K uptake by weeds because of rice straw and cowpea treatments were similar to hoeing treatment in both seasons. The increases in ear grain weight and grain yield ha?1 due to cowpea and hoeing treatments were similar to rice straw one. In 2019 season, cowpea treatment was the superior practice for improving N, P and K uptake of maize, significantly leveling hoeing for K uptake. The values of gross returns and benefit/cost ratio of cowpea and sorghum extract, respectively, were higher than rice straw application. In conclusion, cowpea as a live mulch achieved acceptable weed control in maize by reducing weeds growth and lowering their ability to deplete the soil nutrients. Also, cowpea treatment improves growth and yield of maize with better utilization of nutrients. Thus, cowpea could be exploited as an eco-friendly method of weed management programs in maize cultivation.

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107.
108.

To investigate the effect of different planting dates and irrigation regimes on six canola cultivars, a 2-year (2014–2016) experiment was conducted at the Seed and Plant Improvement Institute of Karaj. The experiments were conducted as the factorial split-plot in a randomized complete block design including six canola cultivars (Gabriella, Brutus, Triangle, Marathon, Danube, and Natali), two irrigation regimes (fully irrigated and irrigation termination at the flowering stage) and two planting dates (October 1 and November 1). The results showed that irrigation termination from the flowering stage prevented the supply of required material for filling the seeds and the metabolism of the seed compounds and reduced the growth period of the seed. Therefore, a reduction was observed in the content of oleic and linoleic acids and proline. Also, water deficit stress caused an increase in the glucosinolate content of the seed. The response of canola cultivars was different in terms of fatty acids, so that the Natali cultivar had higher palmitic, oleic acids, and proline content compared to the other cultivars at both planting dates. Fully irrigated treatment and planting date of October 1 produced the highest amount of seed and oil yield (4659 and 2073?kg ha?1), palmitic acid (5.5%), and proline (22.7?μmol/g) content, and the lowest glucosinolate content (13.2?mg/g). Generally, the Natali cultivar and planting date of October 1 and the fully irrigated regime are highly recommended in the studied area regarding qualitative traits and yield of canola.

  相似文献   
109.
Genetic Resources and Crop Evolution - In order to assess the genetic diversity among six Egyptian rice cultivars and developing cultivars resistant to different rice stem borers, random amplified...  相似文献   
110.

For effective varietal improvement of horticultural crops peach (Prunus persica) and nectarine (Prunus persica var. nucipersica), information about their population structure and genetic relatedness plays an important role. In this study we used retrotransposon-based markers (iPBS) to estimate the genetic diversity and population structure of 48 peach and nectarine genotypes from various distinct geographical regions of Punjab and Khyber Pakhtunkhwa, Pakistan. A total of 461 alleles were identified from PCR amplicons derived from nine iPBS primer pairs with an average of 8.5 alleles/locus. Among all four groups the genotypes collected from Swat and Hunza had the highest and the lowest expected heterozygosity, unbiased expected heterozygosity and Shannon’s information index, respectively. We constructed a Neighbour-Joining dendrogram and performed principal coordinate analysis based on the distance matrices, and both forms of analysis grouped the 48 genotypes into two distinct clusters. The STRUCTURE software distributed the forty-eight genotypes into two main populations (k?=?2) indicating a low diversity between genotypes collected from Chakwal, Swat, Mansehra and Hunza.

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