不同形态硼对油菜幼苗铝毒的缓解效应及其FTIR特征分析

采用水培法,以油菜品种Cao 221167为试验材料,设置无机态硼酸(BA)和有机态山梨醇硼(SB)及不同Al~(3+)(0、100、200和500μmol L~(–1))处理,研究不同形态硼(B)对油菜幼苗铝(Al)毒的缓解作用及不同形态B之间的缓解效应差异,以及利用FTIR(傅里叶红外光谱)技术分析叶片各物质含量的变化。结果表明,Al毒胁迫下,不同形态B(BA和SB)处理,显著提高植株生物量和根系长度(0、100、200和500μmol L~(–1) Al毒胁迫下BA处理根长分别增加了52.15%、101.45%、366.70%和18.73%;SB处理分别增加了46.80%、133.98%、261.36%和10.77%),提高色素含量和SOD活性,而降低了Al含量、MDA含量和POD活性。不同形态B处理下,油菜幼苗在200μmol L~(–1) Al~(3+)处理下长势、生物量及色素含量最高。在500μmol L~(–1) Al~(3+)处理下,油菜幼苗株高、根长、总干鲜重及色素含量显著低于无Al处理;FTIR分析表明,Al毒胁迫下油菜叶片中蛋白质和低聚糖等含量明显上升,加硼明显降低了蛋白质和低聚糖的含量,且BA处理降低幅度明显高于SB处理。说明不同形态B(BA和SB)的添加均明显缓解Al毒,且BA对Al毒缓解效果优于SB,这为农业生产中施用何种硼肥来缓解Al毒起到一定的指导作用。     

Influencing in vitro clonal propagation of Chonemorpha fragrans(moon) Alston by culture media strength,plant growth regulators,carbon source and photo periodic incubation

Chonemorpha fragrans is an endangered medicinal woody climber,regarded among alternative plant sources of camptothecin.Camptothecin is a monoterpene indole anti-cancer alkaloid with annual trade value of over three billion U.S.dollars in the recent,and is used in the production of its analog drugs approved for the chemotherapy of cancer of varied types.Effects of plant growth regulators,culture media strength and photoperi-odic duration on the micropropagation ef ciency of C.fragrans from nodal segment explants were studied on Murashige and Skoog(MS)medium amended with Thidiazuron(TDZ),Benzylaminopurine(BAP)or Kinetin(Kin).Thidiazuron was more ef cient over BAP and Kin when half basal MS medium was used over full or quarter strength.Results of carbon source experiment showed sucrose as the most effective over glucose,fructose,and maltose in the clonal production.Studies on the photope-riodic incubation duration showed 12 h as the best light period and sub or supra-optimal resulted in the production of abnormal and albino micro shoots.Experimental results on the evaluation of physiological,biochemical parameters showed the role of pigment molecules and antioxidant systems in the production of albino micro shoots.     

Farmer’s Perception of and Factors Influencing Agroforestry Practices in the Indus River Basin,Pakistan

Agroforestry practices of farming communities are investigated in southern Punjab province, Pakistan. It is hypothesized that rural people of this areas are more inclined than elsewhere in the province to practice agroforestry due to greater profitability than cropping. A landholder survey revealed that the majority of farmers are inclined to plant trees on their land. Low accessibility of institutional credit is a constraint for both agroforestry farmers (AF) and non-agroforestry farmers. However, among AF respondents only 24% were found to need credit for agroforestry practice, as against nearly 76% for crop production. Mostly farmers were found to have positive perceptions regarding agroforestry practice, because they understand the multiple benefits from growing trees, compared with cropping where farmers face various constraints, including poor access to credit, natural hazards, and little support from local authorities. Further, effort to sensitize farmers that growing trees has multiple benefits compared to only cultivation of field crops can bring about change in farmer’s perceptions and attitudes in the Indus River basin, resulting in motivation for agroforestry adoption.     

Therapeutic Potential and Nutraceutical Profiling of North Bornean Seaweeds: A Review

Malaysia has a long coastline surrounded by various islands, including North Borneo, that provide a suitable environment for the growth of diverse species of seaweeds. Some of the important North Bornean seaweed species are Kappaphycus alvarezii, Eucheuma denticulatum, Halymenia durvillaei (Rhodophyta), Caulerpa lentillifera, Caulerpa racemosa (Chlorophyta), Dictyota dichotoma and Sargassum polycystum (Ochrophyta). This review aims to highlight the therapeutic potential of North Bornean seaweeds and their nutraceutical profiling. North Bornean seaweeds have demonstrated anti-inflammatory, antioxidant, antimicrobial, anticancer, cardiovascular protective, neuroprotective, renal protective and hepatic protective potentials. The protective roles of the seaweeds might be due to the presence of a wide variety of nutraceuticals, including phthalic anhydride, 3,4-ethylenedioxythiophene, 2-pentylthiophene, furoic acid (K. alvarezii), eicosapentaenoic acid, palmitoleic acid, fucoxanthin, β-carotene (E. denticulatum), eucalyptol, oleic acid, dodecanal, pentadecane (H. durvillaei), canthaxanthin, oleic acid, pentadecanoic acid, eicosane (C. lentillifera), pseudoephedrine, palmitic acid, monocaprin (C. racemosa), dictyohydroperoxide, squalene, fucosterol, saringosterol (D. dichotoma), and lutein, neophytadiene, cholest-4-en-3-one and cis-vaccenic acid (S. polycystum). Extensive studies on the seaweed isolates are highly recommended to understand their bioactivity and mechanisms of action, while highlighting their commercialization potential.     

氮肥配施下不同C/N作物残渣还田对红壤温室气体排放的影响

氮肥配施能够促进还田秸秆的分解,为了解其对不同C/N秸秆还田下温室气体排放的影响,采用培养实验方法,研究了油菜饼(C/N为4)、玉米秸秆(C/N为28)、水稻秸秆(C/N为41)和小麦秸秆(C/N为71)等4种不同C/N植物残渣在不同量氮肥(无氮、低氮和高氮)配施下对红壤温室气体(CO2、CH4和N2O)排放的影响。结果显示,氮肥配施增加了不同植物残渣的CO2-C累积排放量,且仅在高C/N的小麦秸秆处理中发现存在显著性差异,在低氮和高氮下CO2-C累积排放量分别达到1 271.44、1 212.83 mg·kg-1,显著高于无氮肥配施的883.40 mg·kg-1。土壤N2O累积排放量最大的为油菜饼处理组,低氮量的配施进一步增强了N2O的产生,其累积排放量达到5 550.42μg·kg-1,显著高于无氮肥配施的4 430.44μg·kg-1,然而当氮肥施用量进一步增加时却抑制了N2O的排放(3752.84μg·kg-1)。氮肥配施并未显著影响玉米秸秆和小麦秸秆处理组的N2O累积排放量。在培养期内,每一个处理均表现为CH4的吸收现象,氮肥施用能够增加土壤对CH4的累积吸收量,但差异显著性仅在对照和油菜饼处理中发现。     

中亚热带丘陵区茶园和林地土壤春季N2O排放及其影响因素

中亚热带地区春季降雨频繁,茶园施肥量大,该季节茶园土壤氧化亚氮(N_2O)排放量较高,研究春季茶园土壤N_2O排放及其影响因子有一定意义。以中亚热带丘陵区土壤为对象,采用静态箱-气相色谱法,研究了两种植茶年限茶园和林地土壤春季N_2O排放特征及其影响因子。结果表明:茶园N_2O排放量明显高于林地,50年茶园N_2O排放量明显高于20年茶园,林地N_2O的排放量最少;50年茶园、20年茶园和林地土壤春季N_2O累积排放量分别为2.07、1.39、0.22 kg·hm-2。两种植茶年限茶园土壤N_2O排放通量均与土壤NO_3~--N含量呈显著正相关(P0.05),林地土壤N_2O排放通量则与土壤NH_4~+-N含量呈极显著正相关关系(P0.01);茶园和林地土壤N_2O排放通量均与5 d累积降雨量之间存在显著的相关性。多元逐步回归分析显示,茶园土壤N_2O排放通量受土壤温度和NO_3~--N含量影响,共同解释其48%~49%的变化;林地土壤N_2O排放通量受土壤温度和NH_4~+-N含量影响,共同解释其55%的变化。这项研究显示施肥对春季茶园N_2O排放的促进作用与降雨有关。     

药隔期低温胁迫对小麦干物质积累、转运和分配及产量的影响

为探明药隔期低温胁迫对小麦产量的影响,以烟农19、新麦26为供试材料,在小麦药隔期进行不同程度(T1:2℃/4h、T2:0℃/4h、T3:-2℃/4h)的低温处理,研究药隔期低温胁迫对小麦干物质积累、转运和分配及产量的影响.结果 表明:药隔期低温胁迫显著降低小麦干物质积累量,不同抗倒春寒性小麦品种间干物质积累量存在差异,抗倒春寒性弱的小麦品种降幅更大.其中烟农19的T1、T2、T3处理分别降低33.4％、46.2％和54.7％,而新麦26则分别降低了50.1％、59.3％和72.4％.不同处理小麦籽粒、穗轴+颖壳、茎鞘+叶的干物质积累量均低于CK,且随着低温胁迫程度的加重呈明显降低趋势.小麦花前干物质的转运量、转运效率以及花前贮藏干物质对籽粒的贡献率均随着低温胁迫程度加重呈降低趋势.同时低温胁迫显著降低小麦籽粒和穗轴+颖壳的干物质分配比例,增加茎鞘+叶的分配比例.T1、T2和T3处理显著降低了小麦的穗粒数和千粒重及籽粒产量,烟农19的T1、T2和T3处理分别减产56.06％、86.36％和98.10％;新麦26的T1、T2和T3处理分别减产96.15％、98.07％和98.46％.药隔期低温胁迫显著降低小麦干物质的积累量、花前干物质的转运量、转运效率以及花前贮藏干物质对籽粒的贡献率和籽粒干物质分配比例,严重减少光合同化物向穗部的转运和分配,影响穗部小花的正常发育,从而导致穗粒数的减少,这是造成小麦减产的主要原因.     

Total intravenous anesthesia with ketamine–medetomidine–propofol in horses

Propofol is a potentially useful intravenous anesthetic agent for total intravenous anesthesia (TIVA) in horses. The purpose of this study was to compare the anesthetic and cardiorespiratory effects of TIVA following the administration of propofol alone(P–TIVA) and ketamine–medetomidine–propofol (KM–P–TIVA) in adult horses. The carotid artery was translocated to a subcutaneous position during TIVA with P–TIVA (n = 6) or KM–P–TIVA (n = 6). All horses were premedicated with medetomidine [0.005 mg kg^–1, intravenously (IV)]. Anesthesia was induced with midazolam (0.04 mg kg^–1 IV) and ketamine (2.5 mg kg IV). All horses were orotracheally intubated and breathed 100% oxygen. The KM drug combination (ketamine 40 mg mL^–1 and medetomidine 0.05 mg mL^–1) was infused at a rate of 0.025 mL kg^–1 hour^–1. Subsequently, a loading dose of propofol (0.5 mg kg^–1, bolus IV) was administered to all horses; surgical anesthesia (determined by horse response to incision and surgical manipulation, positive response being purposeful or spontaneous movement of limbs or head) was maintained by varying the propofol infusion rate as needed. Arterial blood pressure and HR were also monitored. Both methods of producing TIVA provided excellent general anesthesia for the surgical procedure. Anesthesia time was 115 ± 17 (mean ± SD) and 112 ± 11 minutes in horses anesthetized with KM–P–TIVA and P–TIVA, respectively. The infusion rate of propofol required to maintain surgical anesthesia with KM–P–TIVA was significantly less than for P–TIVA (mean infusion rate of propofol during anesthesia; KM–P–TIVA 0.15 0.02 P–TIVA 0.23 ± 0.03 mg kg^–1 minute^–1, p = 0.004). Apnea occurred in all horses lasting 1–2 minutes and intermittent positive pressure ventilation was started. Cardiovascular function was maintained during both methods of producing TIVA. There were no differences in the time to standing after the cessation of anesthesia (KM–P–TIVA 62 ± 10 minutes versus P–TIVA 87 ± 36 minutes, p = 0.150). The quality of recovery was good in KM–P–TIVA and satisfactory in P–TIVA. KM–P–TIVA and P–TIVA produced clinically useful general anesthesia with minimum cardiovascular depression. Positive pressure ventilation was required to treat respiratory depression. Respiratory depression and apnea must be considered prior to the use of propofol in the horse.