Physiological Basis of Irrigation Scheduling for Seed Production in Egyptian Clover Syn. Berseem (Trifolium alexandrinum L.) Crop

A field experiment was conducted to find out the critical physiological stages of irrigation schedules inducing better growth, physiological efficiency and seed yield potential of berseem ( Trifolium alexandrinum L., Var. S-99-1). For this purpose eight irrigation treatments were made comprised of four treatments of three irrigation (W₁, W₂, W₃ and W₄), three treatments of four irrigation (W₅, W₇ and W₈) and one treatment of five irrigation (W₆) at various physiological stages i. e. regeneration, flower initiation, full bloom, seed initiation and advance seed development stage.
Thus based on the experimental results the physiological role of watering in berseem seed production could be discussed as:
With-holding of irrigation either at regeneration or at full bloom stage developed potential water stress in plants as indicated by high proline content of irrigation treatments — W₄, W₁ and W₇; and further brought out disturbance on the formation of carotene, synthesis of water soluble sugar and translocation of sugar towards reproductive organs during grain development stage. These stresses adversely affected the plant growth and flowering behaviour. The irrigation at seed initiation stage increased the seed yield. Continuous irrigation did not appear to be useful. Thus it can be concluded that irrigation at three critical physiological stages i. e. regeneration, full bloom and seed initiation was found to be essential for obtaining potential seed yield of berseem.     

Processing traits and digestibility of extruded dog foods with soy protein concentrate

Soya bean protein concentrate (SPC) with two particle sizes were evaluated on extrusion parameters, kibble formation, digestibility and palatability of dog foods. Eight diets were extruded: PBM—control diet based on poultry by‐product meal (PBM); GM—a diet in which corn gluten meal (GM) replaced 45% of the diet protein; cSPC15%, cSPC30% and cSPC45%—diets in which SPC of coarse particle size (600 μm) replaced 15%, 30% and 45% of the diet protein; and sSPC15%, sSPC30% and sSPC45%—diets in which SPC of small particle size (200 μm) replaced 15%, 30% and 45% of the diet protein. The digestibility of nutrients was evaluated for the PBM, GM, cSPC45% and sSPC45% diets, using six dogs per food. The PBM, GM and cSPC45% diets were compared for palatability. Data were submitted for analysis of variance, and the means were compared by polynomial contrasts or Tukey's test (p < .05). The cSPC increased the specific mechanical energy (SME) application, extrusion temperature and pressure linearly, resulting in lower kibble density and higher expansion and starch gelatinization (SG) (p < .01). When comparing the PBM, GM, cSPC45% and sSPC45% diets, higher SME, extrusion temperature and pressure, SG and kibble expansion were verified for the cSPC45% diet (p < .05). The DM, fat and crude protein digestibility were similar among diets. Faecal pH, ammonia and lactate did not differ, demonstrating that the removal of oligosaccharides and soluble non‐starch polysaccharides of SPC produces an ingredient with mostly non‐fermentable fibre. Dogs preferred the PBM to the GM diet (p < .05), but consumed the PBM and cSPC45% foods equally. In conclusion, SPC exhibited good extrusion functionality, favouring kibble expansion and SG, with high digestibility, similar to that of PBM. The removal of soluble compounds from soya beans resulted in an ingredient with low fermentable fibre content, which did not alter faecal formation or characteristics.     

红檵木叶色变化的生理生化研究

红檵木(Loropetalum chinense var.rubrum)在春季新叶初发时,花红叶红,且叶片红艳可人,具有很高的观赏价值.但随着叶龄的增大,叶色发生较大变化,在初夏叶色变为暗红色,到了盛夏高温季节,叶色几乎变成了绿色,出现了生产上称之的"高温返青"现象.     

水稻土磷环境敏感临界值的研究

采用室内测试方法研究了3组质地(粘土、重壤土和轻壤土)水稻土水溶性磷(0.01mol·L-1CaCl2-P)与土壤测试磷(Olsen-P和Bray1-P)及土壤磷饱和度的关系。结果表明,水稻土因淹水耕作,其磷释放潜力明显高于旱地土壤,水溶性磷随土壤测试磷的增加而增加。土壤测试磷及磷的饱和度与土壤水溶性磷的关系存在转折点,当土壤磷超过转折点时,土壤水溶性磷和磷的释放潜力明显增加。在好气条件下,供试水稻土磷环境敏感临界值(转折点)在Olsen-P50～75mg·kg-1、Bray1-P90～140mg·kg-1和磷饱和度21%～23%之间;在厌气条件下,供试水稻土磷环境敏感临界值(转折点)在Olsen-P35～45mg·kg-1、Bray1-P75～115mg·kg-1和磷饱和度16%～18%之间,超过临界值土壤磷素可对环境产生非常明显的负影响,不应再施用磷肥和粪肥。     

微囊藻毒素-LR对生菜非结构性碳水化合物代谢的影响

【目的】研究低质量浓度微囊藻毒素-LR（MC-LR）慢性暴露对生菜（Lactuca sativa）叶片及根系非结构性碳水化合物代谢的影响,为富营养化水体在生菜灌溉中的应用提供理论指导。【方法】以散叶生菜为试验材料,采用土培试验方法,设置不同质量浓度（0（对照组）,1,5,10,30 μg/L）MC-LR的水溶液灌溉生菜30 d,通过分析生菜叶片及根系中可溶性糖（葡萄糖、果糖和蔗糖）及淀粉含量、蔗糖和淀粉代谢相关酶活性的变化,探讨生菜非结构性碳水化合物代谢对MC-LR慢性暴露的响应。【结果】10和30 μg/L MC-LR组生菜对MC-LR的富集系数较5 μg/L MC-LR组分别显著上升10.85%和17.83%（P＜0.05）,而对MC-LR的转运系数分别显著下降17.46%和13.85%（P＜0.05）。与对照组相比,1 μg/L MC-LR组生菜净光合速率显著提高了9.17%（P＜0.05）,叶片中果糖含量及根系中葡萄糖含量和淀粉酶（AMS）活性分别显著增加了52.71%,19.13%和37.01%（P＜0.05）;5,10和30 μg/L MC-LR组生菜净光合速率提高,但差异不显著（P＞0.05）,叶片和根系中葡萄糖、果糖和蔗糖含量均显著增加（P＜0.05）,叶片中性转化酶（NI）活性分别显著降低了27.10%,38.01%和37.29%（P＜0.05）,淀粉合成酶活性分别显著增加20.92%,24.57%和30.28%（P＜0.05）,根系蔗糖合成酶、蔗糖磷酸合成酶（SPS）和AMS活性均显著增加（P＜0.05）。【结论】1 μg/L MC-LR水溶液灌溉对生菜叶片和根系中非结构性碳水化合物的分布和代谢影响较弱;而5～30 μg/L MC-LR水溶液灌溉通过促进生菜根系淀粉分解和蔗糖代谢活性,维持体内较高浓度的可溶性糖,从而提高生菜的抗逆性。     

山羊可溶型干细胞因子mRNA在不同毛色皮肤组织中的表达水平简

为探讨可溶性干细胞因子（stem cell factor, SCF）基因表达水平与山羊毛色间的相关性,本试验利用实时荧光定量PCR（QRT-PCR）技术研究了SCF基因mRNA在黑色和白色山羊皮肤中的表达量,并对结果进行统计分析。经内参基因校正后,黑色山羊皮肤中可溶型SCF的相对表达量是白色山羊相对表达量的0.27倍（P>0.05）。可溶型SCF mRNA表达量可能与山羊毛色表型不存在相关性。     

青藏高原不同垂穗披碱草居群营养品质季节动态比较

摘要:对青藏高原地区6个垂穗披碱草（Elymus nutans）居群8个不同生育期的可溶性糖(WSC)和粗蛋白质(CP)含量进行了测定。结果表明,居群间不同生育期WSC和CP含量存在显著差异(P<0.05),种源地来自青海共和县居群和甘肃临潭县居群WSC含量在整个生育期显著高于其他4个居群;CP含量甘肃玛曲县居群显著高于其他居群。整个生育期,WSC含量呈单峰曲线,初花至盛花期最高(P<0.05),初花期WSC含量最高为6.91%,最低为1.58%,CP含量整体表现为下降趋势,完熟期最低。不同居群间WSC和CP含量均表现出一定变异度,其变异系数变幅分别为36.47%～51.29%和4.76%～20.29%。相关性分析表明,WSC与CP含量呈显著负相关。     

牛血清中口蹄疫病毒非结构蛋白抗体时间分辨荧光免疫分析检测方法的建立

为研究快速定量检测牛血清中口蹄疫病毒非结构蛋白抗体的方法,试验通过优化抗原表达条件等步骤,在大肠杆菌原核表达系统中表达可溶性的3A-3B融合蛋白,并基于纯化的可溶性融合蛋白建立口蹄疫病毒非结构蛋白抗体时间分辨荧光免疫分析检测试剂盒。结果表明:建立的方法能够检测牛血清中的口蹄疫病毒非结构蛋白抗体,敏感性高,特异性强,对其他相关的牛类病原无交叉反应,其组内与组间变异系数分别低于10%和15%,具有良好的重复性。对300份临床牛血清样品进行检测,同Procheck公司的口蹄疫非结构蛋白抗体试剂盒进行比较,阳性样品符合率96%,阴性样品符合率93.3%,总的符合率95.7%。重复性试验组内与组间变异系数均小于10%。文章首次建立了口蹄疫病毒非结构蛋白抗体时间分辨荧光免疫分析检测方法,同传统的ELISA方法相比,该检测方法特异性相当、敏感性更高,操作更简单、快速,具有较高的应用推广价值。     

水溶有机肥对水稻促早熟的效果研究

为验证水溶有机肥促进水稻早熟的作用,减轻不利天气对水稻产量的影响,采用对比试验的方法,从水稻生育期、病害发生、茎蘖动态、产量性状和经济效益等方面,分析水溶有机肥对水稻生产的影响.试验结果显示,水溶有机肥能使水稻成熟期提早2 d,增强植株抗逆性,增产增效.     

不同苜蓿品种耐盐性初探

以NaCl为胁迫因子,设置质量分数0、0.3%、0.5%、0.7%和0.9%5个盐浓度梯度,对6个苜蓿Medicago sativa品种进行盐胁迫处理,通过测定发芽势、发芽率、株高、根长、可溶性糖含量和丙二醛含量,对供试苜蓿进行耐盐性研究。试验数据显示:随着盐浓度的增加,苜蓿的发芽势和发芽率逐渐降低,株高和根长逐渐缩短,可溶性糖含量逐渐增加。综合评比表明:新牧1号耐盐性最强,敖汉苜蓿耐盐性最弱。