玉米种质资源对弯孢叶斑病抗性鉴定与评价

2012²013年,采用田间人工接种的方法对新引进的164份国外玉米种质和122份国内常用玉米种质资源进行了玉米弯孢叶斑病的抗性鉴定与评价。鉴定结果表明:玉米种质对弯孢叶斑病的抗性表现存在差异,总体对弯孢叶斑病的抗病能力较低,表现抗病的种质较少,仅有57份,且抗性种质以中等抗病为主,其余229份种质表现感病或高度感病;新引进的国外玉米种质对弯孢叶斑病的抗病能力高于国内常用玉米种质的抗病能力,从新引进的国外玉米种质中筛选出了37份抗性种质,为抗病育种提供了重要基础材料。     

河西走廊制种玉米3种真菌性叶斑病的诊断与识别

玉米大斑病、玉米小斑病和弯孢菌叶斑病是河西走廊制种玉米生育中后期发生的主要叶部病害。为了提高对这3种叶斑病的田间诊断和识别水平,对其发病情况进行了田间调查,归纳总结出3种病害的症状特点,并对引起病害的病原菌进行了分离与鉴定。结果表明,3种叶斑病在发病时期、病斑形态、病斑大小、病状等方面区别明显;在供试的10种玉米自交系品种中,大斑病、小斑病和弯孢菌叶斑病的发病率和病情指数存在明显的差异;分离到引起玉米叶斑病的真菌病原13种,其中玉米弯孢菌叶斑病Curvulairia lunata(Walke)Boedijn、玉米大斑病Exserohilum turcicum(Pass)Leonard et Suggs和玉米小斑病Bipolaris maydis(Nishik.et Miyake)Shoemaker分离率较高。     

玉米弯孢菌叶斑病的研究进展

综述了该病的危害、病原、发生与流行、防治措施、抗源鉴定和抗性遗传研究进展,探讨了存在的主要问题.今后要加强对玉米弯孢菌叶斑病的抗源鉴定和抗性遗传研究,为抗病育种和种质改良研究奠定基础.     

玉米弯孢菌叶斑病抗性的ADAA遗传模型的分析

以P138等8个玉米自交系进行不完全双列杂交, 在1997～1999年用新月弯孢菌的孢子悬液分别对亲本、 F1、 F2、 BC群体进行接种鉴定, 采用加性-显性-上位性(ADAA)模型进行遗传分析. 结果表明: 玉米对弯孢菌叶斑病的抗性遗传以加性效应和显性效应为主, 它们可解释表型变异的69.58%. 从加性效应和显性效应的预测值来看, 自交系P138     

2005—2007年辽宁省玉米区试品种抗病性分析

就2005-2007年辽宁省玉米区试参试品种对大斑病、弯孢菌叶斑病、灰斑病、茎腐病和丝黑穗病的抗病性情况进行了统计分析,结果表明,参试品种对弯孢菌叶斑病和茎腐病表现为中抗以上水平的数量逐年略有下降,对灰斑病和大斑病表现为抗性水平的品种数量逐年提高,对丝黑穗病表现为抗性水平的品种数量保持稳定.     

玉米弯孢病病原菌ISSR-PCR反应体系的建立及优化

为了对玉米弯孢病菌的鉴定、区域发生关系以及遗传多样性等进行研究,采用单因素试验优化玉米弯孢叶斑病菌ISSR-PCR反应体系中模板DNA、引物、dNTPs、Taq酶、Mg~(2+)的用量,并确定每条引物的最佳退火温度。结果表明,最佳反应体系为:模板DNA 1.6μL(25 ng/μL)、引物1.4μL(5μmol/L)、dNTPs 0.25μL(2.5 mmol/L)、Taq酶0.4μL(2.5 U/μL)、Mg~(2+)0.8μL(25 mmol/L)、10×Taq Buffer 2μL、dd H2O 13.55μL。在该体系下选用3个玉米弯孢病菌的全基因组DNA,分别对52条ISSR引物进行筛选,筛选出16条多态性高、扩增稳定的ISSR引物。玉米弯孢病菌ISSR-PCR反应体系的建立为利用ISSR分子标记技术对该病原菌进行遗传分析奠定了基础。     

玉米对弯孢菌叶斑病抗性的遗传效应分析

通过对玉米不同组合F1代对弯孢菌叶斑病抗性的分析,发现抗×感组合F1代的抗性大多介于双亲之间,而抗×抗组合和感×感组合F1代的抗性大多超过双亲,特别是抗×抗组合F1代的抗性具有一定的累加现象。不同正反交组合的抗性分析表明:抗性遗传不具有细胞质效应,属于细胞核遗传。F2代抗性分离检测证明,玉米对弯孢菌叶斑病的抗性是由多基因控制。     

玉米不同品种对弯孢霉叶斑病的抗性与降雨量的关系

试验主要分析了不同玉米品种弯孢霉叶斑病的抗性与降雨量之间的关系，结果表明：近三年来，在聊城玉米弯孢霉叶斑病发生并不严重，其发病程度主要受到7月和8月总降雨量的影响，发病程度随降雨量的增加而明显加重，且品种抗病性越弱病情增加越明显，但6月下旬的降雨量对弯孢霉叶斑病的发病程度的影响不明显。     

H2O2和Ce(NO3)3·6H2O对棉花幼苗抗低温效应的影响

试验分析了H2O2(双氧水)和Ce(NO3)3.6 H2O(硝酸铈)浸种对棉花幼苗抗低温效应的影响。通过对幼苗长度、根系活力、POD(过氧化物酶)活性、CAT(过氧化氢酶)活性和PrO(脯氨酸)含量的测定,结果显示:H2O2和Ce(NO3)3.6 H2O混合液对棉花幼苗抗低温效应有比较显著的影响,其中以0.50 mmol/L H2O2 35μg/ml Ce(NO3)3.6 H2O混合液效果最佳。     

大白菜中保护酶活性及H2O2含量变化与TuMV抗性关系的研究

选取抗TuMV的8407、河304和感TuMV的冠291和春月黄为试验材料,于苗期接种TuMV-C4,接种后测定24 d内叶片中超氧化物岐化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）这3种过氧化氢代谢相关酶的活性以及过氧化氢H2 O2的含量。结果表明：接种TuMV后, POD、CAT的活性及H2 O2含量的变化在不同材料之间存在明显差异。抗病材料在接种后,POD、CAT的活性及H2 O2含量虽有变化,但均能逐渐恢复正常;感病材料在接种后,POD、CAT的活性及H2 O2含量均有较大变化,且始终无法恢复正常。总体而言,叶片中的H2 O2和CAT与大白菜的TuMV抗性关系较为紧密,其次是POD,而SOD与TuMV抗性的关系不大。     

NO对损伤诱导的豌豆幼苗叶片抗氧化系统的影响

为了明确损伤后豌豆幼苗叶片内NO产生的途径及NO对其诱导的抗氧化系统的作用,以豌豆幼苗为试材,研究损伤胁迫下其内源NO含量、NR和NOS活性的变化,以及只有NO供体SNP处理和NO清除剂PTIO、NOS抑制剂L-NAME、NR抑制剂NaN₃喷施后损伤处理过24 h 时对豌豆幼苗叶片内H₂O₂和O₂ ^-·含量变化及对抗氧化酶SOD、POD、CAT、APX等的活性影响。结果表明,损伤处理后0~60 h 内豌豆幼苗叶片内NO含量呈双峰曲线;其中损伤处理早期（第1 峰值）NO的主要来源是NOS酶促途径,而后期（第2 峰值）NO的主要来源是NR酶促途径;损伤处理24 h 豌豆幼苗叶片内NO含量最高,此时H₂O₂和O₂ ^-·含量接近对照水平,而SOD、POD、CAT、APX等的活性显著高于对照,NO供体SNP处理时有类似的结果,NO清除剂PTIO 处理后H₂O₂和O₂ ^-·含量升高,SOD、POD、CAT、APX等的活性降低。以上研究结果表明,NO可能通过增强保护酶的活性来降低损伤诱导的膜脂过氧化程度。     

Exogenous Application of Glycinebetaine Modulates Activities of Antioxidants in Maize Plants Subjected to Salt Stress

The influence of exogenously applied glycinebetaine (0, 50 and 100 m m ) as a foliar spray at different growth stages, i.e. vegetative, reproductive or both at the vegetative and reproductive stages on gas exchange characteristics, glycinebetaine (GB) and the activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) was examined in plants of two maize cultivars, Golden and C-20 grown under saline conditions. Salt stress caused a marked decrease in photosynthetic capacity, chlorophyll contents and SOD activity in both maize cultivars. However, activities of CAT and POD remained almost unchanged in both maize cultivars under salt stress. Accumulation of GB increased with an increase in exogenous level of GB, i.e. 100 m m GB spray caused a greater accumulation of GB in the leaves of maize plants than did 0 or 50 m m . Although exogenously applied GB enhanced photosynthetic capacity of salt-stressed plants of both cultivars, it enhanced the activities of antioxidant enzymes, SOD, CAT and POD, in salt-stressed plants of cv. C-20 only. Overall, the adverse effects of salt stress on maize plants were alleviated by the exogenous application of GB at different growth stages, which up-regulated photosynthetic capacity and the activities of some antioxidant enzymes.     

外源NO供体对水分亏缺下玉米叶片碳同化关键酶及抗氧化系统的影响

为了探讨外源NO供体(硝普钠, SNP)对水分亏缺下玉米叶片碳同化关键酶及抗氧化系统的影响及其调控机制, 在20% PEG-6000模拟水分亏缺胁迫下, 研究了SNP对玉米品种驻玉309幼苗叶片光合碳同化核酮糖-1,5-二磷酸羧化/加氧酶(Rubisco)和Rubisco活化酶(RCA)活性及其基因表达、抗氧化酶活性及其同工酶谱变化的影响。结果表明, 在水分亏缺胁迫下, SNP显著上调玉米叶片rbc L、rbc S、rca β基因的相对表达量, 尤其是叶片rbc S基因的相对表达量增加1.86倍, 叶片Rubisco、RCA活性分别提高32.7%和14.67%; 叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性及其同工酶谱带的宽度和亮度显著增强, 而ROS积累量明显降低。说明在PEG水分亏缺胁迫下, SNP能显著提升玉米幼苗叶片光合碳同化能力及抗氧化酶活性, 降低ROS积累及其对细胞膜造成的损伤, 提高玉米的抗干旱性。     

一氧化氮对双孢蘑菇采后生理及贮藏品质的影响

以硝普钠（SNP）为一氧化氮供体,研究了不同浓度NO在常温（25±1℃）和低温（4±1℃）条件下对双孢蘑菇‘F56’贮藏过程中相关品质（失重率、开伞率、可溶性固形物、维生素C（Vc）、游离氨基酸含量）以及过氧化氢酶（CAT）、过氧化物酶（POD）和多酚氧化酶（PPO）活性的影响。结果表明,0.09 mmol/L SNP释放的NO显著抑制了双孢蘑菇采后失重率和游离氨基酸含量的上升,减缓了可溶性固形物含量的增加、延缓Vc的降解,抑制了开伞率的增大;使CAT、POD的活性显著增强,同时降低PPO活性。因此,0.09mmol/L SNP处理显著提高了常温和低温下双胞蘑菇‘F56’ 贮藏期间的CAT、POD活性,抑制了PPO活性的升高,延缓了菇体品质的下降。     

水杨酸通过一氧化氮信号诱导抗氧化 防护来提高小麦幼苗根部耐盐性

水杨酸和一氧化氮在植物研究中都被认为是调控一系列生理过程的重要内源信号分子。采用药理学和生物化学的方法,研究发现外源水杨酸溶液对盐诱导小麦根部组织的氧化伤害具有保护作用。盐处理(150mmol/L)显著提高根部组织的脂质过氧化水平以及抑制根的生长;同时添加100μmol/L的水杨酸(SA)不仅可以有效的降低脂质过氧化水平以及部分增加根的生长,而且激活了包括SOD、POD和APX等抗氧化酶的活性。此外,一氧化氮(NO)供体硝普钠(SNP)处理能得到与上述SA处理相类似的生物学表型。进一步的研究发现,SA的这种生物学功能很可能与NO有关,因为结合采用NO专一性清除剂cPTIO的处理则不同程度地逆转了SA的各种缓解效应。更重要的是,SA能通过模拟SNP的作用来诱导小麦幼苗根部大量释放NO。上述研究表明,SA通过NO信号上调小麦幼苗根部抗氧化防护来提高耐盐性。     

CMS水稻不同器官的膜脂过氧化水平

比较了ＣＭＳ水稻不育系珍汕９７Ａ及其同核异质保持系珍汕９７Ｂ的叶片、幼穗和花药中的膜脂过氧化、活性氧水平及活性氧清除酶活性。结果表明：与可育花药相比，不育花药中Ｈ２Ｏ２和Ｏ２＾－水平较高，丙二醛（ＭＤＡ）含量也高，而超氧化物歧化酶（ＳＯＤ）、过氧化氢酶（ＣＡＴ）、过氧化酶（ＰＯＤ）和抗坏血酸过氧化物酶（ＡＳＡ－ＰＯＤ）活性则较低；幼穗中，不育系的Ｈ２Ｏ２和ＭＤＡ含量高于保持系，其它指标基本无差异；     

不同破眠处理对油桃休眠芽H2O2含量及 相关酶活性的影响

为进一步探讨H2O2代谢与果树芽自然休眠解除的关系,检测了人工破眠过程中‘曙光’油桃芽内H2O2含量和过氧化氢酶（CAT）、过氧化物酶（POD）活性的影响。选用的人工破眠处理分别为50℃高温（HT）处理、单氰胺（HC）处理和TDZ（TDZ）处理。结果表明,50℃高温和单氰胺效果相似,都能显著打破芽深休眠,并且抑制芽内CAT活性,引起H2O2含量增加,但2个处理对POD活性的影响都不大。TDZ打破深休眠的效果较差,对芽内H2O2含量、CAT活性、POD活性均未表现出显著影响。CAT活性抑制和H2O2积累可能是50℃高温和单氰胺打破自然休眠作用机制的重要组成部分。     

水杨酸对烟草抗黄瓜花叶病毒的诱导效应

通过外源水杨酸（Salicylic acid,SA）处理烟苗,研究了水杨酸处理的烟草接种黄瓜花叶病毒后,其病情指数及抗病相关酶活性和H2O2含量的变化。结果表明：接种CMV后21d,SA处理烟株的病情指数显著低于对照;SA预处理的烟株在接种CMV前后叶片内的过氧化物酶（POD）活性和过氧化氢（H2O2）含量提高,过氧化氢酶（CAT）活性下降。表明水杨酸具有诱导烟草抗黄瓜花叶病毒的效应。     

Induction of Defense Enzymes and Control Effect of Endogenous and Rhizosphere Bacteria on Verticillium Wilt of Cotton

[Objective] The colonization in soil, promoting cotton growth effects, inducing resistance of cotton and controlling effects to cotton Verticillium wilt of Bacillus vanillea SMT-24, B. velezensis BHZ-29, B. subtilis SHT-15 and B. atrophaeus SHZ-24 were studied in this paper, which provides a scientific basis for better control of cotton Verticillium wilt. [Method] The antagonistic resistance of these bacteria to Verticillium dahliae was judged by observing the inhibition zone; the number of colonization in the rhizosphere soil was tested to represent the colonization ability of antagonistic bacteria; the growth promoting effect of strains on cotton was determined by analyzing cotton plant height, root length, root hair number and number of leaves; the effect of antagonistic strains on cotton induced resistance was explored by determining catalase (CAT), superoxide dismutase (SOD), phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), and peroxidase (POD) activities in cotton leaves, and investigating the disease index of cotton after inoculation with antagonistic bacteria solutions. [Result] SMT-24, BHZ-29, SHT-15 and SHZ-24 strains significantly inhibited the growth of V. dahliae and formed a clear zone of inhibition. After 2 to 22 days of the third inoculation, these strains of bacteria could survive in the root soil, increase the plant height, leaf number, and root hair number of cotton plants, as well as the activities of cotton CAT, SOD, PAL and POD enzymes, but reduced the disease index. [Conclusion] SMT-24, BHZ-29, SHT-15 and SHZ-24 strains can promote cotton growth, increase the activities of some related defense enzymes, and effectively control cotton Verticillium wilt.     

Induction of Drought Tolerance in Maize (Zea mays L.) due to Exogenous Application of Trehalose: Growth,Photosynthesis, Water Relations and Oxidative Defence Mechanism

The present investigation was conducted to assess the ameliorative effects of foliar‐applied trehalose on growth, photosynthetic attributes, water relation parameters and oxidative defence mechanism in two maize cultivars under field water deficit conditions. Various components of the experiment comprised two maize cultivars (EV‐1098 and Agaiti‐2002), two water‐stress levels (irrigation after 2 weeks and irrigation after 3 weeks during the entire period of growth), and two levels of trehalose (0 and 30 mm ) and four replicates of each treatment. Water stress significantly reduced the plant biomass production, photosynthetic attributes and water relation parameters in both maize cultivars. In contrast, water stress considerably increased the leaf malondialdehyde (MDA) contents, the activities of antioxidant enzymes such as peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT), and the levels of non‐enzymatic compounds such as ascorbic acid and tocopherols. In contrast, water stress caused a marked reduction in leaf phenolic contents. Foliar‐applied trehalose significantly increased plant biomass production, and improved some key photosynthetic attributes and plant–water relation parameters. The ameliorative effect of exogenously applied trehalose was also observed on the activities of some key antioxidant enzymes (POD and CAT) and non‐enzymatic compounds (tocopherols and phenolics). Overall, exogenously applied trehalose considerably improved drought tolerance of maize plants by up‐regulating photosynthetic and water relation attributes as well as antioxidant defence mechanism.