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关键词： Agricultural runoff   Organic substrates   Nitrate removal   Bacterial community   Denitrification   Denitrifying bacteria  

摘要： The effects of plant-based carbon source addition on wastewater NO3--N removal and the involved microorganisms, especially denitrifying bacteria, were investigated. A synthetic wastewater (NO3--N, 15 mg/L) was treated through the batch experiment, which included three inoculation cycles (7 days/cycle), and was conducted at 25 degrees C. Four natural plant substrates, namely, rice straw (RS), wheat straw (WS), ryegrass (RG), and reed (RD), were used as carbon sources and supplemented at the rate of 1% (w/v). The results showed that both RS and WS performed well in promoting NO3--N removal (79.55-97.07%). While RG removed only 22.08% of NO3--N in the first cycle, the removal efficiency increased afterward (86.09-95.82%). Conversely, the NO3--N removal rate of RD decreased from 95.10 to 24.77% as a result of its low ability to supply carbon. With respect to the microorganisms, the RS treatment resulted in more bacteria and denitrifying genes such as narG, nirK, nirS, and norB than other treatments, while the highest number of nosZ gene copies was recorded in the WS treatment. Sequencing results revealed that Firmicutes (18.19-56.96%), Proteobacteria (38.82-74.80%), and Bacteroidetes (3.15-4.15%) were three dominant bacterial phyla for RS, WS, and RD treatments. Furthermore, the genera Enterobacter, Massilia, and Bacillus were the main denitrifying bacteria participating in the NO3--N removal. Furthermore, correlation analysis indicated that the denitrifying genus Sphingobacterium played an important role in enhancing nitrogen removal. This study suggested that RS is the superior plant-based carbon source for denitrifying bioreactors used in agricultural runoff treatment.

摘要： Determination and characterization of resistance reactions of crops against fungal pathogens are essential to select resistant genotypes. In plant breeding, phenotyping of genotypes is realized by time consuming and expensive visual plant ratings. During resistance reactions and during pathogenesis plants initiate different structural and biochemical defence mechanisms, which partly affect the optical properties of plant organs. Recently, intensive research has been conducted to develop innovative optical methods for an assessment of compatible and incompatible plant pathogen interaction. These approaches, combining classical phytopathology or microbiology with technology driven methods - such as sensors, robotics, machine learning, and artificial intelligence - are summarized by the term digital phenotyping. In contrast to common visual rating, detection and assessment methods, optical sensors in combination with advanced data analysis methods are able to retrieve pathogen induced changes in the physiology of susceptible or resistant plants non-invasively and objectively. Phenotyping disease resistance aims different tasks. In an early breeding step, a qualitative assessment and characterization of specific resistance action is aimed to link it, for example, to a genetic marker. Later, during greenhouse and field screening, the assessment of the level of susceptibility of different genotypes is relevant. Within this review, recent advances of digital phenotyping technologies for the detection of subtle resistance reactions and resistance breeding are highlighted and methodological requirements are critically discussed.

摘要： In self-incompatible plants the female style rejects self pollen, yet the extent to which the female style in the many self-compatible species can still select between different pollen genotypes and thus bias fertilization success is unclear. A new study identifies the molecular basis for how styles of the self-compatible coyote tobacco bias the fertilization success of pollen genotypes using matching gene expression patterns in a manner analogous to cryptic female choice in animals.

关键词： 初中生物学   信息化   教学资源  

摘要： 伴随着我国社会经济的不断进步和世界经济全球化的步伐，信息技术得到飞速发展，网络与通信技术特别是多媒体通信技术在生产实践中的应用，影响着我们生产生活和学习的方方面面，不断改变着我们生产生活方式和学习方式，信息化时代已经到来。信息化教学资源就是利用信息技术和网络通信技术进行教学资源的设计、开发的资源，可以打破时空的限制，具有多样性、丰富性和趣味性的特点，利于教师教学和学生学习的资源。早在21世纪初，专家学者们就已经认识到了信息化教学资源的开发和建设对于推动课程变革和提高教学质量等方面的重要意义，开始利用信息技术和网络通信技术搭建平台，开发教学资源。事实上，通就目前的研究现状而言，理论层面的研究大于实际进行资源建设的研究，本文将针对初中生物课程标准中“生物全中的绿色植物（二）”这一部分课程内容进行实际的信息化教学资源的设计、开发和应用建议，以此实现理论与实践的结合。　　本文通过文献研究法查阅大量国内外的信息化教学模式与教学资源设计与开发与应用的研究文献，了解研究现状，。通过设计研究法，在建构主义理论、混合式教学理论和混合是教学理论的指导下，对“生物圈中的绿色植物（二）”这个一级主题进行信息化教学资源的设计与开发工作，遵循目标导向原则、对象适应性原则、最小代价原则和科学性原则设计和开发出具有系统性、交互性、直观性、生命性等特性的信息化资源。　　确定按照《初中生物课程标准》的重要概念分为教师“教”的资源与学生“学”的资源来展开进行。其中，教师“教”的资源又包括《初中生物课程标准》、对《初中生物课程标准》的分析、教材、相关研究资料、优秀教学案例以及素材库和练习题六个方面；学生“学”的资源包括自主学习任务单、思维导图、微视频、练习题和拓展资料五个方面，以此来帮助教师和学生来展开“教”和“学”的工作。并对其中的微视频、自主学习任务单和思维导图的开发一《绿色植物的呼吸作用》为例进行了详细介绍。最后给出了信息化教学资源的在应用于课前、课中环节的建议。

关键词： 核心概念   基本理解   基本问题  

摘要： 生物学概念性知识是建立生命观念的基础,是学生能力发展的载体。基于对重要概念的理解,形成基本问题,根据学生能力发展的需求优化问题,落实概念,培养学生能力。

关键词： 生物教学   理性思维   探究活动   误区   引导  

摘要： 理性思维是一种建立在证据与逻辑推理基础上的思维方式,也是生物学科核心素养的重要组成部分,具有重要的教育价值。本文以生物学探究活动为切入点,分析理性思维的内涵,以'绿色植物参与生物圈中的水循环'一课为例,探讨在生物探究活动中学生常见的思维误区及引导策略,旨在为提升初中生物学探究活动教学有效性提供参考。

关键词： 囊果草   生物学特性   种子传播   点格局分析   生态适应  

摘要： 为明确荒漠植物囊果草生物学特性及其种群分布格局的生态适应意义,以北疆地区温性荒漠中的特有植物囊果草为研究对象,对其生物学特性、种子传播方式及野外种群的分布格局进行了观测。结果表明,囊果草具膀胱状膜质果囊和膨大的不规则块状根茎,每株平均具果囊8.29个,果囊底部和侧面具网状脉络,且底部脉络较粗,不易破裂,顶部无脉络但具蓝紫斑,成熟时易破裂,每个果囊内平均包含球形种子2.82个。囊果草的花具有暂时闭合特性。囊果草为风滚式传播植物,一方面,地上果囊随风滚动时释放内部种子完成远距离传播,随着果囊体积的增大,果囊在不同粗糙程度微地形条件下的移动距离呈线性递增趋势,随地面粗糙度的增加,果囊最短移动距离显著减小(P<0.05),散布的种子数量则显著增加(P<0.05),且果囊移动距离与散布种子数量之间显著负相关(r=0.30,P<0.05);另一方面,地下块状根茎以营养生殖的方式在原位萌发。囊果草种群的分布格局与其生殖方式密切相关。在小尺度范围内(0~50m),随着空间尺度的扩大,囊果草种群幼苗和成株的分布格局表现为从均匀分布到聚集分布再到随机分布的特点;在中等尺度范围内(3.0~17.5m),幼苗和成株的空间关联性表现为正关联,随着空间尺度的递增,二者之间的关联性逐渐减小且关联性不显著。

关键词： NAC   生物学功能   调控   综述  

摘要： 在长期进化过程中,植物体内形成精密的调控机制来抵御环境胁迫,转录因子在转录水平调控胁迫相关基因的表达进而参与调控植物的抗逆反应。NAC (NAM、ATAF1/2、CUC2)是植物特有的最大的转录因子家族之一,具有独特的结构特征,由保守的N端结构域和多变的C端转录激活域组成。很多物种的NAC转录因子已经被发现并进行了功能鉴定。一般而言,同源进化关系上属于同一家族的NAC转录因子具有相似的生物学功能。近年来,对NAC转录因子生物学功能的研究不断深入,表明NAC转录因子可以通过植物激素信号通路广泛调控植物的生长发育,如器官边界的建成、次生壁和根的生长、衰老过程等植物生命历程,并响应多种非生物和生物胁迫。本文综述了植物NAC转录因子参与生长发育、响应胁迫等生物学过程的研究进展,为深入探讨其调控机理及更好地将NAC基因应用于农业生产提供参考。