Optimization of rhizosphere cooling airflow for microclimate regulation and its effects on lettuce growth in plant factory

In plant factories, the plant microclimate is affected by the control system, plant physiological activities and aerodynamic characteristics of leaves, which often leads to poor ventilation uniformity, suboptimal environmental conditions and inefficient air conditioning. In this study, interlayer cool airflow(ILCA) was used to introduce room air into plants' internal canopy through vent holes in cultivation boards and air layer between cultivation boards and nutrient solution surface(interlayer). By using optimal operating parameters at a room temperature of 28℃, the ILCA system achieved similar cooling effects in the absence of a conventional air conditioning system and achieved an energy saving of 50.8% while bringing about positive microclimate change in the interlayer and nutrient solution. This resulted in significantly reduced root growth by 41.7% without a negative influence on lettuce crop yield. Future development in this precise microclimate control method is predicted to replace the conventional cooling(air conditioning) systems for crop production in plant factories.     

高寒地区燕麦根际高效PGPR菌培养条件研究

用乙炔还原法及比色法对高寒草地燕麦根际分离的5个PGPR菌株(O3、O5、O6、O7、O8)在不同光照、pH值、盐分浓度和温度梯度下的生长能力进行了研究。结果表明:5株PGPR菌在较低的光照强度下生长受阻,高强度的光照有利于细菌的生长繁殖,其最适生长范围为2 000～3 000 Lx;固氮酶活性在pH 7.0～7.2范围之间表现最高;盐分(NaCl)浓度高于1 % 时PGPR菌生长受阻;PGPR菌最适宜的生长温度范围为25～30 ℃。     

Increased ammonification,nitrogenase, soil respiration and microbial biomass N in the rhizosphere of rice plants inoculated with rhizobacteria

Azospirillum brasilense and Pseudomonas fluorescens are well-known plant growth promoting rhizobacteria. However, the effects of A. brasilense and P. fluorescens on the N cycles in the paddy field and rice plant growth are little known. This study investigated whether and how A. brasilense and P. fluorescens contribute to the N transformations and N supply capacities in the rhizosphere, and clarified the effects of A. brasilense and P. fluorescens on the N application rate in rice cultivation. Inoculations with A. brasilense and P. fluorescens coupled with N application rate trials were conducted in the paddy field in 2016 and 2017. The inoculations of rice seedlings included four treatments: sterile saline solution(M_0), A. brasilense(Mb), P. fluorescens(Mp), and co-inoculation with a mixture of A. brasilense and P. fluorescens(Mbp). The N application rate included four levels: 0 kg N ha~(–1)(N_0), 90 kg N ha~(–1)(N_(90)), 180 kg N ha~(–1)(N_(180)), and 270 kg N ha~(–1)(N_(270)). The results indicated that the Mbp and Mp treatments significantly enhanced the ammonification activities in the rhizosphere compared with the M_0 treatment, especially for higher N applications, while the Mbp and Mb treatments greatly enhanced the nitrogenase activities in the rhizosphere compared with the M_0 treatments, especially for lower N applications. Azospirillum brasilense and P. fluorescens did not participate in the nitrification processes or the denitrification processes in the soil. The soil respiration rate and microbial biomass N were greatly affected by the interactions between the rhizobacteria inoculations and the N fertilizer applications. In the Mbp treatment, N supply capacities and rice grain yields showed no significant differences among the N_(90), N_(180), and N_(270) applications. The N application rate in the study region can be reduced to 90 kg N ha~(–1) for rice seedlings co-inoculated with a mixture of A. brasilense and P. fluorescens.     

农用植物酵素的生态效应研究进展

为明确农用植物酵素发酵机理及生态效应,本研究分析2005—2018年国内外已发表75篇文献,总结现有农用植物酵素发酵机理、工艺、成分、农业应用和问题挑战,重点分析农用植物酵素生态效应特点及作用机制。结果表明,农用植物酵素是富含矿质养分、代谢活性物质和有益微生物菌群的复杂而稳定的生态系统,在土壤改良、促进作物生长及防虫抑菌等方面均发挥重要作用。展望未来,农用植物酵素是获得当地土著有益微生物的一项简便易行的方法,也是变废为宝且便于推广的一项新兴技术。     

植物类甜蛋白基因家族研究进展

植物受到生物或非生物胁迫时,病程相关蛋白（pathogenesis-related proteins,PRs）PR-5家族（又称类甜蛋白,thaumatin-like proteins,TLPs） 在植物组织内迅速表达并积累,从而快速提高植物抗性。研究发现许多植物的TLPs具有抗真菌活性,而且转TLPs基因的植物能够抑制病害发展进程。介绍了TLPs基因的分布起源和进化特征、结构特征、生理功能;分析了TLPs基因在不同植物中的差异表达特征、TLPs的抗真菌机制以及TLPs基因在植物抗病遗传改良中的应用;提出了植物TLPs未来研究的主要问题以及TLPs基因在林木病理学和林木抗病遗传育种中的应用前景。参81     

杀虫剂在木本植物体内传导理论研究进展

杀虫剂通过在植物体内输导而使其通体带药来控制害虫。药剂进入植物体内 ,通过植物蒸腾作用产生的拉力随液流到达作用部位 ,在植物体内呈不均匀分布 ,从而达到控制害虫的目的 ;性质不同的杀虫剂在不同植物体内传导机理不同 ;传导速度与植物生理状态、气候因子、药剂的理化性质等诸因素有关 ;杀虫剂在植物体内的代谢不同于常规施药方法 ,一般在植物代谢旺盛的部位残留量较大 ;通过该技术控制害虫的大量试验表明 ,植物体内注药的方法是行之有效的 ,且对环境的污染显著小于常规施药方法     

森林土壤微生物生物量动态变化研究进展

土壤微生物生物量是土壤有机质中最为活跃的部分,它调节着陆地生态系统的生物地球化学过程.不少研究表明,森林土壤微生物生物量具有明显的季节动态变化特征.本文在综合前人研究的基础上,对森林土壤微生物生物量的季节动态变化规律及其影响因子进行了归纳和总结,发现森林土壤微生物生物量的季节波动主要有夏高冬低型、夏低冬高型和干-湿季节交替循环型3种模式,这些变化类型主要与土壤温度、土壤湿度、季节干-湿交替循环或与植物的生长节律等有关.在今后的相关研究中,要加强对森林土壤微生物生物量季节动态变化调控机理的研究,并注重对土壤微生物生物量C 与土壤微生物生物量N、P动态变化的耦合关系的研究.     

Recent advances in plant immunity with cell death: A review

Cell death is an important physiological phenomenon in life. It can be programmed or unprogrammed. Unprogrammed cell death is usually induced by abiotic or biotic stress. Recent studies have shown that many proteins regulate both cell death and immunity in plants. Here, we provide a review on the advances in plant immunity with cell death, especially the molecular regulation and underlying mechanisms of those proteins involved in both cell death and plant immunity. In addition, we discuss potential approaches toward improving plant immunity without compromising plant growth.     

气候变化及人为活动驱动下的西南喀斯特生态水文研究评述

喀斯特地区地表关键带结构十分复杂,土层浅薄且持水能力弱,地下裂隙多而渗透速率快,导致地表水分亏缺频繁、生态脆弱、污染物扩散快速等一系列生态环境问题。喀斯特地区的合理开发利用和生态环境保护,对深刻理解其生态水文过程有着极大的诉求。迄今为止,喀斯特生态水文学已经获得了重要进展,极大地提升了人们对植被水分来源与耗散机理、坡面水文快速过程、环境变化的生态水文效应等方面的认识,并构建了多种模型,为喀斯特地区生态治理、环境保护和水资源合理利用等提供了理论依据和技术支撑。但受限于喀斯特地表结构的复杂性,目前所获得的结论也存在很多不足和不确定性。本文从喀斯特生态水文过程与机理、喀斯特流域生态水文和喀斯特生态水文模型研究三个方面概述了喀斯特生态水文研究进展,介绍了课题组在相关方面的主要成果,并提出了未来研究中应进一步重视的问题。     

茶树根系XTHs和伸展蛋白对不同浓度铝的响应

为探索铝对茶树根系生长的影响,以一年生安吉白茶扦插苗为研究材料,比较不同铝浓度处理28 d后茶树根系生长的表型差异、生长参数,以及细胞壁相关蛋白XTHs[木葡聚糖内转糖苷酶(XET)/水解酶(XEH)]和伸展蛋白(Expansins)的响应。结果表明,与无铝对照相比,加铝处理的茶树根系在表型、生长参数上均表现出了促进生长的现象,尤其是0.4、1.0 mmol·L^-1的铝处理下与对照差异显著(P<0.05),根系总长分别增加了206%和209%、根尖数分别增加了175%和166%、根系表面积分别增加了227%和286%、根系体积分别增加了246%和385%。相应地,茶树根系中CsEXPB14、CsEXLA8基因表达量在0.4 mmol·L^-1铝处理下显著(P<0.05)高于对照与4.0 mmol·L^-1铝处理组。Expansins活性也在0.4 mmol·L^-1铝浓度下最高,较不加铝处理提高了84.3%。CsXTH14基因表达量在0.4、1.0 mmol·L^-1铝浓度下较对照显著(P<0.05)上调,XET酶活性亦表现出随铝浓度升高而增加的趋势,直至4.0 mmol·L^-1的铝浓度下才受到显著抑制。XTHs和 Expansins基因表达、XET和Expansins活性与根系生长呈正相关关系,表明一定浓度的铝(≤1 mmol·L^-1)处理,可以通过诱导XTHs和Expansins基因表达上调,提高XET和Expansins活性,促进茶树根系的生长。     

王朗自然保护区紫果云杉径向生长与气候因子的关系

紫果云杉林Picea purpuea是四川王朗国家级自然保护区的重要群落类型。在其主要分布的原始林内设置10个半径为8m的样圆进行树轮取样与分析。研究结果发现:大部分紫果云杉都出现了一次以上的生长释放现象,通过ARSTAN方法建立年表同气候因子进行显著性相关分析发现,影响紫果云杉生长的气象因子是上年7、8月和当年6、10月的气温以及上一年12月的降雨,其中温度是影响树木径向生长的主要气候因子,通过单年分析进一步印证了这种关系。通过开展紫果云杉树轮年代学研究,了解该云杉生长状况,科学认识树木生长对气候变化的响应机制,为预测气候变化对该树种生长、分布影响及保育提供科学依据。     

土壤类型和树种对根际土丛枝菌根真菌群落及其根系侵染率的影响

为合理利用丛枝菌根(Arbuscular Mycorrhiza,AM)真菌促进喀斯特退化土地植被恢复,采用形态学方法研究了土壤类型(石灰土和黄壤)和宿主植物种类(紫弹树(Celtis biondii Pamp)、红锥(Castanopsis hystrix)和单性木兰(Kmeria septentrionalis Dandy))对AM真菌群落结构的影响。研究共分离鉴定了2属14种AM真菌,其中幼套球囊霉(Glomus etunicatum)是石灰土和黄壤共有的优势种,石灰土特有的AM真菌包括地球囊霉(G.geosporum)、白色球囊霉(G.albidum)、双型球囊霉(G.ambisporum)、象牙白球囊霉(G.eburneum)和细凹无梗囊霉(G.scrobiculata),而波状无梗囊霉(A.undulata)是黄壤特有的AM真菌。土壤类型对AM真菌孢子密度,Shannon多样性指数以及侵染率具有显著影响;宿主植物种类与AM真菌Shannon多样性指数呈显著相关。石灰土紫弹树和单性木兰根际土AM真菌孢子丰度显著高于黄壤相同植物的,而红锥无显著差异;石灰土紫弹树和红锥的AM真菌物种丰富度及Shannon多样性指数均高于黄壤同种植物的。土壤类型对AM真菌孢子密度、物种丰富度、Shannon多样性指数和侵染率均有显著影响,对均匀度指数也有显著影响;植物种类对Shannon多样性指数有显著影响,且AM真菌物种丰富度、Shannon多样性指数和侵染率受土壤类型与植物种类交互作用的显著影响;土壤p H和全钾含量对AM真菌群落影响显著。因此,利用AM真菌促进喀斯特植物定植生长与植被恢复过程中,应该考虑喀斯特土壤AM真菌具有区域特异性和物种偏好性。     

根际微生态防治作物土传真菌病害的机制研究进展

土传真菌病害分布范围广、传播速度快且危害性大,已成为世界性难题.化学杀菌剂一直被认为是防治土传真菌病害的重要手段,但是长期大量使用化学杀菌剂不仅会造成农药残留、病原菌的抗药性增加,而且还会造成食品安全、粮食安全及土壤、环境污染等问题,严重制约农业健康可持续发展.根际微生态是与植物根系发生紧密联系和相互作用的土壤微域,是...     

植物生长调节剂对无花果高空压条繁殖的影响

以无花果为试材,选择2年生健壮枝条进行高空压条,用不同质量浓度的IBA、IAA处理环剥伤口,观测了不同处理的生根情况,结果表明:质量浓度为600mg/L的NAA处理效果最好.     

The cytochrome P450 superfamily: Key players in plant development and defense

The cytochrome P450(CYP) superfamily is the largest enzymatic protein family in plants, and it also widely exists in mammals, fungi, bacteria, insects and so on. Members of this superfamily are involved in multiple metabolic pathways with distinct and complex functions, playing important roles in a vast array of reactions. As a result, numerous secondary metabolites are synthesized that function as growth and developmental signals or protect plants from various biotic and abiotic stresses. Here, we summarize the characterization of CYPs, as well as their phylogenetic classification. We also focus on recent advances in elucidating the roles of CYPs in mediating plant growth and development as well as biotic and abiotic stresses responses, providing insights into their potential utilization in plant breeding.     

居住区植物景观对老年人邻里社交的影响——以上海虹口区为例

居住区绿地是老年人日常生活中最常使用的活动场所之一,为老年人的社会交往提供了重要的场所。为了更好地了解居住区绿地植物景观与老年人社交活动的相关性,本文以上海市虹口区2000年以后建成的3个居住区为例,采用问卷调查收集居住区绿地中老年人邻里社交的相关数据,并使用SPSS与贝叶斯网络模型分析居住区绿地植物景观与老年人邻里社交之间的关系。结果表明,居住区中邻里社交主要受老年人对居住区绿地植物景观的感知水平与居住区绿地植物景观的维护感知的影响,居住区中拥有较多绿地植物景观能够促进老年人邻里间的社会交往。     

内生菌定殖、促生及降低作物有机污染的机理研究（Ⅰ）：定殖与促生

随着社会经济快速发展,土壤污染和退化问题日益突出。内生菌不仅在促进植物生长、适应逆境和维持植物健康等方面具有明显优势,而且能够有效降低植物体内有机污染物含量,是微生态领域研究的热点。利用功能内生菌研发相关产品与技术,对高效利用污染土壤生产安全农产品具有重要意义,为此本研究通过系列论文进行了总结论述。论文Ⅰ着重从内生菌的来源、定殖于植物体内的途径及影响因素、促生作用机制等方面进行综述,提出了当前内生菌-植物互作研究中存在的问题与今后重点研究的方向。后续的论文Ⅱ将重点论述内生菌降低作物体内有机污染物含量的机理。     

Improving the efficiency and effectiveness of global phosphorus use: focus on root and rhizosphere levels in the agronomic system

Phosphorus (P) is essential for life and for efficient crop production, but global P use with limited recycling is inefficient in several sectors, including agronomy. Unfortunately, plant physiologists, agronomists, farmers and end users employ different measures for P use efficiency (PUE), which often masks their values at different scales. The term P use effectiveness, which also considers energetic and sustainability measures in addition to P balances, is also a valuable concept. Major physiological and genetic factors for plant P uptake and utilization have been identified, but there has been limited success in genetically improving PUE of modern crop cultivars. In maize, studies on root architectural and morphological traits appear promising. Rhizosphere processes assist in mobilizing and capturing sparingly soluble phosphate from rock phosphate. Combinations of phosphate-solubilizing microorganisms with ammonium-based nitrogen fertilizer, as well as strategies of fertilizer placement near the roots of target crops, can moderately enhance PUE. The desired concentration of P in the products differs, depending on the final use of the crop products as feed, food or for energy conversion, which should be considered during crop production.     

冰糖橙低产劣质的原因及对策

目的筛选促进柑橘砧木资阳香橙盆栽幼苗生长的丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF),为柑橘菌根种苗应用提供参考,也为利用菌根柑橘种苗抑制柑橘黄龙病探索新途径。方法采用盆栽试验,利用资阳香橙幼苗接种从广西土壤分离纯化获得的15株AMF菌株,研究不同AMF对根系的侵染及对植株的促生效应。结果15株AMF均能与资阳香橙根系形成共生关系。其中,黄雷德克囊霉1 (Redeckera fulvum 1)对植株根系的侵染率最高,达到81.27%;脆无梗囊霉(Acaulospora delicata)的侵染率最低,为8.57%;15株菌株的平均侵染率为50.97%。幼套近明球囊霉(Claroideoglomus etunicatum)和摩西斗管囊霉(Funneliformis mosseae)可促进资阳香橙的生长,其株高、茎粗、叶片数和叶绿素SPAD值均显著高于对照(P<0.05)。结论幼套近明球囊霉和摩西斗管囊霉是促进资阳香橙生长的优势菌株。     

植物生长调节物质对饵料微藻蛋白质和氨基酸的影响

在三角褐指藻、牟氏角毛藻、湛江等鞭藻的f／2培养液中分别添加植物生长调节物质三十烷醇(TA)、6-糠基腺嘌呤(6-FA)和生长素(2，4-D)，在指数生长后期采收微藻，测定三种微藻的蛋白质和氨基酸含量。结果表明，分别添加0．1μg/LTA、0．05μg/L6-FA、0．05μg/L2，4-D能够极显著提高三角褐指藻的蛋白质及必需氨基酸的含量，分别添加0．1μg/LTA、0．25μg／L6-FA、0．05μg/L2，4-D能够显著或极显著提高牟氏角毛藻的蛋白质及必需氨基酸的含量，而三种植物生长调节物质使湛江等鞭藻的蛋白质及必需氨基酸的含量显著减少。