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41.
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.  相似文献   
42.
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.  相似文献   
43.
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。  相似文献   
44.
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   总被引:1,自引:0,他引:1  
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。  相似文献   
45.
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.  相似文献   
46.
47.

Background  

The ultimate goal of proteomic analysis of a cell compartment should be the exhaustive identification of resident proteins; excluding proteins from other cell compartments. Reaching such a goal closely depends on the reliability of the isolation procedure for the cell compartment of interest. Plant cell walls possess specific difficulties: (i) the lack of a surrounding membrane may result in the loss of cell wall proteins (CWP) during the isolation procedure, (ii) polysaccharide networks of cellulose, hemicelluloses and pectins form potential traps for contaminants such as intracellular proteins. Several reported procedures to isolate cell walls for proteomic analyses led to the isolation of a high proportion (more than 50%) of predicted intracellular proteins. Since isolated cell walls should hold secreted proteins, one can imagine alternative procedures to prepare cell walls containing a lower proportion of contaminant proteins.  相似文献   
48.
Seed presoaking improves wheat germination under marginal moisture conditions. The duration of seed presoaking was studied at The University of Arid Agriculture, Rawalpindi, using 10 wheat varieties. Seed presoaking beyond 12 h does not improve germination further, and beyond 21 h, germination rate is drastically reduced.  相似文献   
49.
Four known coumarins, coumarin (1), 7-hydroxy-3-methylcoumarin (2), oreoselone (3) and heraclenin (4), were isolated from aerial part of Halocnemum strobilaceum. Their structures were determined by 1 and 2-D NMR techniques.  相似文献   
50.
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