草坪的冬季管理

冬季来临,草坪草进入休眠期。草坪草的冬季管理好坏,直接影响来年草坪的生长和提高草坪的观赏性。多年来,根据我们绿化养护的经验,并根据草坪草的类型,分别介绍其冬季养护管理的具体措施。 一、暖季型草坪的管理 暖季型草坪草一般有马尼拉草、台湾青和天鹅绒草等。进入冬季,此类草坪草处于休眠状态,地上部分已枯萎,它们除了自身微     

中国的草坪草资源及其开发利用

中国的草坪草资源相当丰富。文章初步分析了草坪草的一般特性、我国草坪草的分类以及主要的草坪草种类,并简要介绍了我国草坪草资源的现状。最后,就如何开发利用我国的草坪草资源并走草坪国产化道路提出建议。     

水肥对草坪草影响的研究进展

施肥和灌溉作为草坪日常养护管理的两大重要措施,是建成高质量草坪的重要保障.从施肥措施中的N、P、K及其三元素配施对草坪草的影响以及灌溉措施中的灌溉频率和灌溉水量对草坪草生长发育的影响等方面,综述近年来草坪草施肥和灌溉研究的热点问题,探讨理想草坪草所需的适合施肥水平和灌溉水平,阐明施肥和灌溉两个措施对草坪草的影响存在一定的互助关系.通过对施肥和灌溉对草坪草生长发育影响的研究作简要的概述,为制定适宜的草坪施肥与灌溉计划,节约水资源利用,减少过量肥料对环境与草坪草生长的不利影响,同时为获得理想的草坪质量提供参考依据.     

草坪蒸散研究进展

草坪蒸散量是指导草坪合理灌溉的重要指标。自20世纪中叶以来,以节水为目的的草坪蒸散研究越来越受到人们的重视。草坪蒸散研究的内容主要包括相互关联的3个方面：草坪蒸散率的测定与比较,草坪蒸散机制的研究和草坪节水灌溉的研究。草坪蒸散率在不同草种间存在不同程度的差异。暖季型草坪草和冷季型草坪草相比普遍具有较低的草坪蒸散率。暖季型草坪草的夏季日平均最大蒸散率为3.0-9.0mm,而冷季型草坪草的为3.6-12.6mm。密度大,生长缓慢的杂交狗牙根、结缕草、野牛草和假俭草的耗水量很低,细羊茅的耗水量中等,而草地早熟禾、高羊茅、1年生早熟禾和匍匐剪股颖的耗水量很大。同种草坪草的不同品种的草坪蒸散率存在差异。有些草种内品种间差异的程度高达64％,不亚于种间。冷季型草坪草品种的蒸散率与留茬量显著相关,但环境因子对品种的蒸散率影响很大,品种的蒸散特性不稳定。与冷季型草坪草相比,暖季型草坪草的种内品种间蒸散率的差异和谐较小。草坪的冠层是草坪蒸散的一个主要外部条件,具有较低蒸散率的草坪往往具备高冠层阻力和低叶面积。土壤水分不受限制时,不同的暖季型草坪草种间的草坪蒸散率与叶片背面的气孔密度显著负相关。但在种内品种间没有表现出相关性。冷季型草坪草种间和种内的叶片气孔数目和草坪的蒸散率不相关。草坪的作物系数是确定最适灌溉量的关键参数,线性梯度灌溉系统比小型蒸渗仪提供的草坪作物系数更接近于实际。当草坪的质量维持在可接受的水平时,以彭曼公式推测的苜蓿的潜在蒸散量为参照蒸散量,高羊茅草坪的作物系数为0.60-0.80,草地早熟禾草坪的作物系数为0.50-0.80。基于草坪冠层温度的作物水分胁迫系数（CWSI）是确定灌溉时机的比较合理的指标。CWSI在不同的季节和不同的草种间表现不稳定,并且这种方法的节水效果也表现不一,还处于发展阶段。草坪蒸散的研究在我国几乎处于空白状态,开展我国的草坪蒸散研究,寻求适合的草坪节水途径已势在必行。     

草坪草种质资源抗旱性及其改良研究进展

本文综述了草坪草抗旱性的形态学、生物学、解剖学和生理学等鉴定方法。介绍了草坪草适应干旱胁迫的形态和生理生化机制。对草坪草种质资源的抗旱性改良进展进行了概述。最后, 对草坪草抗旱性研究中存在的问题和前景进行了讨论。     

冷季型草坪草的耐热性调控研究进展

在非生物胁迫中,高温是影响草坪植物特别是对冷季型草坪草生长和发育最重要的生态因子之一. 高温胁迫会导致冷季型草坪草生长受到抑制、草坪质量下降、草坪植株体内的生理生化代谢紊乱,细胞内产生大量氧自由基,使膜脂过氧化,植株体内蛋白质变性,最后导致细胞死亡. 因此,如何提高冷季型草坪草的耐热性是目前冷季型草坪在热带、亚热带地区建植能否安全越夏的重要问题. 文中综述了国内外冷季型草坪草耐热性调控的研究进展, 在阐明冷季型草坪草耐热性调控原理的基础上,报道了用于草坪草耐热性鉴定的形态、生态、生理和生化等指标,以及通过降低土壤温度、叶面喷施生长调节剂、施肥、灌溉和修剪等养护管理措施来提高冷季型草坪草的耐热性研究进展.     

三种阔叶草坪草对斜纹夜蛾生长发育及营养利用的作用

为了探讨斜纹夜蛾Spodoptera litura对草坪的为害,提供综合治理该虫的理论依据,室内利用白三叶草Trifolium repens、红三叶草T. pratense和马蹄金Dichondra repens 3种阔叶草坪草,分别饲喂斜纹夜蛾幼虫;应用编制实验种群生命表的方法,分析斜纹夜蛾种群生长发育的趋势;同时研究该幼虫对3种草坪草的趋性及营养利用。结果表明：斜纹夜蛾幼虫的趋性表现为白三叶草＞红三叶草＞马蹄金。该虫在3种草坪草上都能够完成生活史;2种三叶草饲喂的该虫幼虫存活率、化蛹率、成蛾率显著高于马蹄金,幼虫期和蛹期则显著短于马蹄金;3种草坪草饲喂的该虫产卵期和平均产卵量相互之间差异不显著,而马蹄金饲喂的产卵前期和雌成虫寿命则显著短于2种三叶草。3种草坪草饲喂的该虫净生长率（Ro）、世代平均周期（T）、内禀生长率（r_m）、周限生长率（λ）、种群加倍时间（DT）及种群增长参数（I）都有差异,其中2种三叶草的各种群增长参数较接近。对5龄幼虫取食3种阔叶草坪草的营养指标测定结果显示：取食马蹄金的相对生长率显著高于取食红三叶草的;取食马蹄金的相对取食量和近似消化率显著高于取食三叶草的;取食马蹄金的食物利用率和食物转化率显著低于取食三叶草的;2种三叶草间无显著差异。综合分析认为,斜纹夜蛾最喜食三叶草,最容易在三叶草草坪上猖獗为害。     

我国暖季型草坪草锈病的研究进展

锈病是暖季型草坪草上的一种重要病害,可明显降低暖季型草坪草的观赏价值和使用价值.综述了目前我国暖季型草坪草锈病的病原物、症状及发生情况、发病规律以及防治方面的研究进展,对目前我国暖季型草坪草锈病研究中存在的问题加以分析,并对暖季型草坪草锈病研究前景加以展望.     

草坪草种质资源抗旱性及其改良研究进展

本文综述了草坪草抗旱性的形态学、生物学、解剖学和生理学等鉴定方法.介绍了草坪草适应干旱胁迫的形态和生理生化机制.对草坪草种质资源的抗旱性改良进展进行了概述.最后,对草坪草抗旱性研究中存在的问题和前景进行了讨论.     

三种暖季型草坪草对二氧化硫抗性的比较

二氧化硫(SO_2)是城市大气污染的重要污染物之一,这已经越来越成为国家迫在眉睫须彻底解决的环境问题,解决SO_2污染问题仍是一个重要的生态与环保课题。草坪植物现已成为城市绿化的主要造景材料,依据植物对大气污染的反应特性来选择城市草坪草种,使之在发挥景观效果的同时,发挥其更好的生态效果。采用人工模拟熏气法,以CK(自然状态)、S1(4.29mg/m~3)、S2(6.44mg/m~3)、S3(8.58mg/m~3)、S4(10.73mg/m~3)5个SO_2浓度水平,对城市常用的3种暖季型草坪草:结缕草(Zoysiajaponica)、百喜草(Paspalum notatum)、狗牙根(Cynodon dactylon)进行SO_2胁迫处理,并测定3种草坪草生理生化指标,最终比较3种草坪草对SO_2的抗性。结果表明:随SO_2浓度增加,3种草坪草的可溶性糖含量(SS)、脯氨酸含量(Pro)、丙二醛(MDA)含量呈增加趋势;结缕草可溶性蛋白(SP)呈先降后升趋势,百喜草则呈先升后降趋势,狗牙根各胁迫处理下其SP含量均低于CK;结缕草和狗牙根过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性呈增加趋势,百喜草SOD和CAT活性呈先升后降趋势,同时其POD活性在各SO_2胁迫处理下均低于CK。将所有测定指标采用模糊数学隶属度公式进行综合相关分析,得出3种草坪草对SO_2的抗性由强到弱的排序为:结缕草狗牙根百喜草。结缕草在SO_2胁迫下与其它两种草坪草相比,表现出了更好的抗性能力,因此,在城市空气不断遭受污染的今天,结缕草可以作为热带和亚热带城市绿化草坪植物的优选草种之一。     

草坪草生物技术研究进展

概述了草坪草植株再生体系和遗传转化体系建立的方法和进展.通过愈伤组织培养、悬浮细胞培养和原生质体培养方法对草坪草的一些种已建立较为完善的植株再生体系.在建立再生体系的基础上,利用原生质体融合、农杆菌介导、基因枪和碳化硅纤维介导等转基因方法在一些草坪草种上建立了遗传转化体系并获得了有一定价值的转基因植株.最后,对草坪草转基因存在的问题和前景作了讨论.     

Controlling Transgene Escape in GM Creeping Bentgrass

Trait improvement of turfgrass through genetic engineering is important to the turfgrass industry and the environment. However, the possible transgene escape to wild and non-transformed species raises ecological and commercial concerns. Male sterility provides an effective way for interrupting gene flow. We have designed and synthesized two chimeric gene constructs consisting of a rice tapetum-specific promoter (TAP) fused to either a ribonuclease gene barnase, or the antisense of a rice tapetum-specific gene rts. Both constructs were linked to the bar gene for selection by resistance to the herbicide glufosinate. Agrobacterium-mediated transformation of creeping bentgrass (cv Penn A-4) with both constructs resulted in herbicide-resistant transgenic plants that were also 100% pollen sterile. Mendelian segregation of herbicide resistance and male sterility was observed in T1 progeny derived from crosses with wild-type plants. Controlled self- and cross-pollination studies showed no gene transfer to non-transgenic plants from male-sterile transgenic plants. Thus, male sterility can serve as an important tool to control transgene escape in bentgrass, facilitating the application of genetic engineering in producing environmentally responsible turfgrass with enhanced traits. It also provides a tool to control gene flow in other perennial species using transgenic technology.     

Expression of a novel antimicrobial peptide Penaeidin4-1 in creeping bentgrass (Agrostis stolonifera L.) enhances plant fungal disease resistance

Background

Turfgrass species are agriculturally and economically important perennial crops. Turfgrass species are highly susceptible to a wide range of fungal pathogens. Dollar spot and brown patch, two important diseases caused by fungal pathogens Sclerotinia homoecarpa and Rhizoctonia solani, respectively, are among the most severe turfgrass diseases. Currently, turf fungal disease control mainly relies on fungicide treatments, which raises many concerns for human health and the environment. Antimicrobial peptides found in various organisms play an important role in innate immune response.

Methodology/Principal Findings

The antimicrobial peptide - Penaeidin4-1 (Pen4-1) from the shrimp, Litopenaeus setiferus has been reported to possess in vitro antifungal and antibacterial activities against various economically important fungal and bacterial pathogens. In this study, we have studied the feasibility of using this novel peptide for engineering enhanced disease resistance into creeping bentgrass plants (Agrostis stolonifera L., cv. Penn A-4). Two DNA constructs were prepared containing either the coding sequence of a single peptide, Pen4-1 or the DNA sequence coding for the transit signal peptide of the secreted tobacco AP24 protein translationally fused to the Pen4-1 coding sequence. A maize ubiquitin promoter was used in both constructs to drive gene expression. Transgenic turfgrass plants containing different DNA constructs were generated by Agrobacterium-mediated transformation and analyzed for transgene insertion and expression. In replicated in vitro and in vivo experiments under controlled environments, transgenic plants exhibited significantly enhanced resistance to dollar spot and brown patch, the two major fungal diseases in turfgrass. The targeting of Pen4-1 to endoplasmic reticulum by the transit peptide of AP24 protein did not significantly impact disease resistance in transgenic plants.

Conclusion/Significance

Our results demonstrate the effectiveness of Pen4-1 in a perennial species against fungal pathogens and suggest a potential strategy for engineering broad-spectrum fungal disease resistance in crop species.     

An efficient method for the production of marker-free transgenic plants of peanut (Arachis hypogaea L.)

Recombinant genes conferring resistance to antibiotics or herbicides are widely used as selectable markers in plant transformation for selecting the primary transgenic events. However, these become redundant once the transgenic plants have been developed and identified. Although, there is no evidence that the selectable marker genes are unsafe for consumers and the environment, it would be desirable if the marker genes can be eliminated from the final transgenic events. The availability of efficient transformation methods can enable the possibility of developing transgenic events that are devoid of the marker gene/s upfront. Taking advantage of the high and consistent transformation potential of peanut, we report a technique for developing its transgenics without the use of any selectable marker gene. Marker-free binary vectors harboring either the phytoene synthase gene from maize (Zmpsy1) or the chitinase gene from rice (Rchit) were constructed and used for Agrobacterium tumefaciens-mediated transformation of peanut. The putative transgenic events growing in vitro were initially identified by PCR and further confirmed for gene integration and expression by dot blots assays, Southern blots, and RT-PCR where they showed a transformation frequency of over 75%. This system is simple, efficient, rapid, and does not require the complex segregation steps and analysis for selection of the transgenic events. This approach for generation of marker-free transgenic plants minimizes the risk of introducing unwanted genetic changes, allows stacking of multiple genes and can be applicable to other plant species that have high shoot regeneration efficiencies.     

草坪草育种研究进展 (综述)

介绍草坪草传统育种和转基因育种的历史与现状,概述草坪转基因育种的操作过程,对植物特别是草坪草转基因过程中存在的一些问题如基因丢失,基因沉默,基因流引起的转基因安全性等进行评述。     

Crossing the divide: gene flow produces intergeneric hybrid in feral transgenic creeping bentgrass population

Gene flow is the most frequently expressed public concern related to the deregulation of transgenic events ( Snow 2002 ; Ellstrand 2003 ). However, assessing the potential for transgene escape is complex because it depends on the opportunities for unintended gene flow, and establishment and persistence of the transgene in the environment ( Warwick et al. 2008 ). Creeping bentgrass (Agrostis stolonifera L.), a turfgrass species widely used on golf courses, has been genetically engineered to be resistant to glyphosate, a nonselective herbicide. Outcrossing species, such as creeping bentgrass (CB), which have several compatible species, have greater chances for gene escape and spontaneous hybridization (i.e. natural, unassisted sexual reproduction between taxa in the field), which challenges transgene containment. Several authors have emphasized the need for evidence of spontaneous hybridization to infer the potential for gene flow ( Armstrong et al. 2005 ). Here we report that a transgenic intergeneric hybrid has been produced as result of spontaneous hybridization of a feral‐regulated transgenic pollen receptor (CB) and a nontransgenic pollen donor (rabbitfoot grass, RF, Polypogon monspeliensis (L.) Desf.). We identified an off‐type transgenic seedling and confirmed it to be CB × RF intergeneric hybrid. This first report of a transgenic intergeneric hybrid produced in situ with a regulated transgenic event demonstrates the importance of considering all possible avenues for transgene spread at the landscape level before planting a regulated transgenic crop in the field. Spontaneous hybridization adds a level of complexity to transgene monitoring, containment, mitigation and remediation programmes.     

Expression of the bacteriophage T4 lysozyme gene in tall fescue confers resistance to gray leaf spot and brown patch diseases

Tall fescue (Festuca arundinacea Schreb.) is an important turf and forage grass species worldwide. Fungal diseases present a major limitation in the maintenance of tall fescue lawns, landscapes, and forage fields. Two severe fungal diseases of tall fescue are brown patch, caused by Rhizoctonia solani, and gray leaf spot, caused by Magnaporthe grisea. These diseases are often major problems of other turfgrass species as well. In efforts to obtain tall fescue plants resistant to these diseases, we introduced the bacteriophage T4 lysozyme gene into tall fescue through Agrobacterium-mediated genetic transformation. In replicated experiments under controlled environments conducive to disease development, 6 of 13 transgenic events showed high resistance to inoculation of a mixture of two M. grisea isolates from tall fescue. Three of these six resistant plants also displayed significant resistance to an R. solani isolate from tall fescue. Thus, we have demonstrated that the bacteriophage T4 lysozyme gene confers resistance to both gray leaf spot and brown patch diseases in transgenic tall fescue plants. The gene may have wide applications in engineered fungal disease resistance in various crops.     

草坪植物遗传转化的研究进展

从草坪植物组织培养与植株再生体系的建立、转基因的研究现状以及转基因育种的应用前景和存在的问题入手,综述了近年来草坪植物遗传转化的研究进展,并对草坪植物遗传转化的几种主要方法作了较为详细的阐述。     

Use of beta-glucuronidase reporter gene for gene expression analysis in turfgrasses

The beta-glucuronidase (GUS) gene has been successfully used as a reporter gene in innumerable number of plant species. The functional GUS gene produces blue coloration in plants upon integration into the plant genome. Because of the ease it provides to analyze the gene expression (as no expensive equipment is needed), GUS gene is surely plant biotechnologist's first choice as a reporter gene. The turfgrass family contains the world's most economically important horticultural crops. There is a world-wide drive for genetic modification of grasses due to its huge economic importance. GUS gene can be transiently or stably expressed in grasses for the purpose of promoter analysis and to study tissue-specific and developmental gene expression. This paper summarizes the use of GUS gene for transient and stable expression studies in various turfgrass species.