The Nutrient Expert decision support system improves nutrient use efficiency and environmental performance of radish in North China          下载免费PDF全文

ZHANG Jia-jia  DING Wen-cheng  CUI Rong-zong  LI Ming-yue  Sami ULLAH  HE Ping 《农业科学学报》2022,21(5):1501-1512

Excessive fertilization has led to nutrient use inefficiency and serious environmental consequences for radish cultivation in North China.  The Nutrient Expert (NE) system is a science-based, site-specific fertilization decision support system, but the updated NE system for radish has rarely been evaluated.  This study aims to validate the feasibility of NE for radish fertilization management from agronomic, economic, and environmental perspectives.  A total of 46 field experiments were conducted over four seasons from April 2018 to November 2019 across the major radish growing regions in North China.  The results indicated that NE significantly reduced N, P₂O₅, and K₂O application rates by 98, 110, and 47 kg ha⁻¹ relative to those in the farmers’ practice (FP), respectively, and reduced N and P₂O₅ inputs by 48 and 44 kg ha⁻¹, respectively, while maintaining the same K₂O rate as soil testing (ST).  Relative to FP and ST, NE significantly increased radish yield by 2.7 and 2.6 t ha⁻¹ (4.2 and 4.0%) and net returns by 837 and 432 USD ha⁻¹, respectively.  On average, NE significantly improved the agronomic efficiency (AE) of N, P, and K (relative to FP and ST) by 42.4 and 31.0, 67.4 kg kg⁻¹ and 50.9, and 20.3 and 12.3 kg kg⁻¹; enhanced the recovery efficiency (RE) of N, P, and K by 11.4 and 7.0, 14.1 and 7.5, and 11.3 and 6.3 percentage points; and increased the partial factor productivity (PFP) of N, P, and K by 162.9 and 96.8, 488.0 and 327.3, and 86.9 and 22.4 kg kg⁻¹, respectively.  Furthermore, NE substantially reduced N and P₂O₅ surpluses by 105.1 and 115.1 kg ha⁻¹, respectively, and decreased apparent N loss by 110.8 kg ha⁻¹ compared to FP.  These results indicated that the NE system is an effective and feasible approach for improving NUE and promoting cleaner radish production in North China.  相似文献   

Purification and characterization of three trypsin isoforms from viscera of sardinelle (<Emphasis Type="Italic">Sardinella aurita</Emphasis>)     

Hayet Ben Khaled  Kemel Jellouli  Nabil Souissi  Sofiane Ghorbel  Ahmed Barkia  Moncef Nasri 《Fish physiology and biochemistry》2011,37(1):123-133

Three trypsin isoforms A, B and C were purified to homogeneity from the viscera of sardinelle (Sardinella aurita). Purification was achieved by ammonium sulfate precipitation (20–70% (w/v)), Sephadex G-100 gel filtration and Mono Q-Sepharose anion-exchange chromatography. The molecular weights of these purified enzymes were estimated to be 28.8 kDa by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE). Based on the native PAGE and casein-zymography, each purified trypsin appeared as a single band. Trypsins A and C exhibited the maximal activity at 55°C, while trypsin B at 50°C. All isoforms showed the same optimal pH (pH 9.0) using Nα-benzoyl-dl-arginine-p-nitroanilide (BAPNA) as a substrate. The three trypsins were stable at temperatures below 40°C and over a broad pH range (7.0–11.0). The activities of the three isoforms were strongly inhibited by soybean trypsin inhibitor and phenylmethylsulfonyl fluoride, a serine protease inhibitor, and partially inhibited by ethylenediaminetetraacetic acid, a metalloenzyme inhibitor. Kinetic constants of trypsins A, B and C for BAPNA were evaluated at 25°C and pH 9.0. The values of K _m and k _cat were 0.125, 0.083 and 0.10 mM, and 2.24, 1.21 and 5.76 s⁻¹, respectively. The N-terminal sequences of the first 10 amino acids were “I V G G Y E C Q K Y” for trypsin A and “I V G G Y E A Q S Y” for trypsins B and C. These sequences showed highly homology to other fish trypsins.  相似文献   

Synergetic use of biochar and synthetic nitrogen and phosphorus fertilizers to improves maize productivity and nutrient retention in loamy soil     

Waqas Ahmad Minhas  Noman Mehboob  Ahmad Nawaz  Sami UL-Allah 《Journal of plant nutrition》2020,43(9):1356-1368

Abstract

This study was designed to investigate the effect of biochar on maize production and nutrient retention with recommended full and half dose of nitrogen (N) and phosphorus (P) nutrition in loamy soil. In the first study, maize was grown in pots with four levels of biochar (0, 2, 4, and 6?t?ha^?1) under two levels of NP fertilizer, viz. recommended (200–150?kg?NP?ha^?1) and it’s half (100–75?kg?NP?ha^?1) dose. The prominent improvement in plant roots traits, leaf area, plant growth, morphological and yield-related parameters were observed with addition of biochar at 2 and 4?t?ha^?1; while, plant height, number of grains per cob, grains and biological yield decreased with biochar addition 6?t?ha^?1 along with full dose of NP nutrition. In subsequent field studies, two levels of biochar along with control (0, 2, 4?t?ha^?1) were investigated. The more improvement in root growth, leaf area and crop growth was observed when biochar was applied at 2?t?ha^?1 with full NP nutrition. Biochar application at 2?t?ha^?1 with full NP nutrition produced the highest grain yield (6.64?t?ha^?1); however, biochar addition (2?t?ha^?1) with half NP nutrition resulted in better grain yield than full dose of NP to enhance maize production as compared with full dose of NP without biochar. Therefore, biochar addition (2?t?ha^?1) with half-recommended dose of NP prominently improved the maize productivity in loamy soil and serve as better in replacement of full dose of NP fertilizer.  相似文献   

Response of cotton genotypes to water and heat stress: from field to genes     

Muhammad Iqbal  Sami Ul-Allah  Muhammad Naeem  Muhammad Ijaz  Abdul Sattar  Ahmad Sher 《Euphytica》2017,213(6):131

Cotton is a crop of tropical and subtropical regions but the seed cotton yield is highly influenced by abiotic stresses like drought and heat. Response of cotton genome to abiotic stresses is highly complex and involve many genes. A comprehensive study, involving cotton genotypes developed through conventional and synthetic tetraploid method, was designed to (i) study the introgression of heat and water stress tolerance by using wild relatives (ii) evaluate genetic markers for marker assisted selection against water and heat stress. Two separate experiments for water and heat stress tolerance with a common control were established. Treatments in each experiment include a control and a stress treatment. Heat stress was applied by sowing crop two month earlier than the control treatment, whereas water stress was imposed by withholding alternate irrigation. Analyses of variance depicted highly significant (P ≤ 0.01) effect of genotypes and both stresses on boll retention, boll weight and seed cotton yield. Interaction of genotypes with stress in both experiments was also highly significant (P ≤ 0.01). Genotypes derived from interspecific crosses performed consistently in stress conditions compared to control which prove it a reliable method to introgress stress related genes from wild parents. Four genes reported for water stress tolerance and five genes reported for heat stress tolerance were evaluated by field results for efficient marker assisted selection (MAS). Results verified drought stress genes but heat stress genes could not explain genetic variability caused by heat stress. It is concluded from the results that separate genes may be responsible for heat stress tolerance for vegetative and reproductive stages, therefore, selection criteria should include both the traits.  相似文献   

Efficacy and toxicity of carboplatin in the treatment of macroscopic mesenchymal neoplasia in dogs     

Céleste Pritchard  Sami Al-Nadaf  Robert B. Rebhun  Jennifer L. Willcox  Katherine A. Skorupski  Amandine Lejeune 《Veterinary and comparative oncology》2023,21(4):717-725

Palliative chemotherapy options for dogs with macroscopic non-osseous mesenchymal tumours are limited. The purpose of this study was to assess the response rate of these tumours to carboplatin chemotherapy. Medical records of 28 dogs treated with carboplatin for macroscopic mesenchymal neoplasia between 1990 and 2022 were retrospectively reviewed. Sixteen dogs with soft tissue sarcoma and 12 dogs with haemangiosarcoma were included. Responses observed included one complete response and three partial responses, for an overall response rate of 14.2% (4/28) and median time to progression of 42 days (range 21–259 days). Responses were only seen in patients with haemangiosarcoma, for a response rate of 33.3% (4/12) and median time to progression for responders of 103 days (range 39–252 days). Median time to progression for dogs with metastatic disease was similar to those with only local disease (distant median: 44 days; local median: 23 days, p = 0.56). Dogs with chemotherapy-naïve disease were compared to dogs having received previous chemotherapy treatment and had a median time to progression of 75 days and 40.5 days respectively (p = 0.13). Twenty-two dogs experienced 48 adverse events, with most being grade 1 or 2 (79%). Carboplatin was well tolerated, with variable macroscopic anti-tumour activity and short response duration. Carboplatin may be an acceptable rescue option for dogs with macroscopic haemangiosarcoma, especially those patients that cannot receive doxorubicin.  相似文献